Re: [EVDL] How crazy am I?
There is quite a bit of information here, http://liionbms.com/php/bms_options.php and here, http://liionbms.com/php/bms-selector.php http://liionbms.com/php/battery_modules.php This is the main page that has several different categories listed, including motor controls http://liionbms.com/php/index.php On Thursday, July 24, 2014 1:14 AM, Ben Goren via EV ev@lists.evdl.org wrote: On Jul 23, 2014, at 3:45 AM, Ben Apollonio via EV ev@lists.evdl.org wrote: On the contrary. Tesla cells discharge at a very LOW current. When you have 85kWh of battery, you only need 3.5C to make 300kW, and C/5 to cruise at 55MPH. Even the 120kW 'supercharger' tops out at about 2C (for the smaller 60kWh battery). I would hazard this is why larger cells are not designed for large currents. RC cars are designed to run for 2 minutes and are trying to maximize power/weight. Most real world applications need more capacity and have to optimize energy/weight, so there's significantly less market for cells at 100Ah and 300C (not to mention that you would then have to find a way to manage 30,000 amps!!). You would seem to be correct. Judging by the battery packs I've found being sold for BEVs at the types of places listed as authorized dealers for Netgain and HPEVS, it looks like the assumption is that you're going to be throwing lots of batteries at the car so you don't need to worry much about individual battery discharge capability. I haven't by any stretch of the imagination done any sort of thorough investigation, but the first pass suggests that something along these lines might be the direction I'd have to head in: http://www.all-battery.com/tenergy3.2v1300mah4.16whlifepo4ifr18650prechargeablebattery-30065.aspx It's a single 18650-sized cell (Wikipedia says that's what the Tesla uses; looks to be a bit bigger than a AA) with a 1.35 Ah capacity. If my math is right, to get to ~10 kWh I'd need 1 kWh / (1.35 Ah * 3.2 V) ~= 2300 cells. Each cell supports up to 10 A continuous discharge...and 23,000 A is not only wy more than I'd need, it sounds positively terrifying. 2300 * 3.2 V ~= 7,400 V, which is again scary overkill -- and, obviously, they'd have to be wired in combinations of series and parallel banks to get that down to a reasonable range. Make the math easy, and do it as 50 packs of 45 batteries each for 144 V, 9.7 kWh, and don't think about it maximum current draw...and ~200 pounds of batteries. And about $9000 in batteries (almost 4x the cost of 144 V of CALB 40 Ah packs), before the cost of the hardware to wire them up and the time that would go into doing the wiring. At that point, what I was thinking of as the advantage of a small pack is long gone. This kind of a n homebrew system still might make more sense for this particular project than an off-the-shelf product, but it would mean a bunch of re-thinking Has anybody here already done this type of research? Is there a graceful way to get to high current capacity with a small pack size? Maybe a different size cell to build the packs from? I'm obviously not an expert on battery technology Thanks again, b -- next part -- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 801 bytes Desc: Message signed with OpenPGP using GPGMail URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140723/295e652d/attachment.pgp ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140724/c0d2a649/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] How crazy am I?
On Jul 24, 2014, at 5:54 AM, Rod Hower rodho...@ameritech.net wrote: This is the main page that has several different categories listed, including motor controls http://liionbms.com/php/index.php Wow -- that is an amazing resource, one that'll keep me quite busy for a while. Thanks! b -- next part -- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 801 bytes Desc: Message signed with OpenPGP using GPGMail URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140724/91978ed8/attachment.pgp ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] How crazy am I?
On Jul 22, 2014, at 8:21 AM, EVDL Administrator via EV ev@lists.evdl.org wrote: For example, the CALB 40ah cells I mentioned are rated for a maximum discharge of 2C (80 amps). At 144v, 80a is 11.5kW. Allowing for losses, that's only about 12hp from your motor! I think I may be a bit confused. If a single 40 Ah cell can provide 80 A (for a little while), shouldn't 45 of those 40 Ah cells be able to provide 80 A * 45 = 3600 A? That 80 A would be at 3.2 V for 256 W. All 45 cells would be at 144 V, for 518.4 kW or ~ 500 hp. That's three times the power of the 260 Windsor engine in the car today, and substantially more than you're going to get in a stock muscle car of any era -- and way more than even a pair of AC-50s or WarP 9s is rated for. So...does discharge scale with the number of batteries, or is it limited by the discharge of a single cell? If the former, I should be more than fine with a 45-cell pack of CALB 40 Ah batteries or equivalent. If the latter...I'm likely screwed Thanks, b -- next part -- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 801 bytes Desc: Message signed with OpenPGP using GPGMail URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140724/f9e034e8/attachment.pgp ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] How crazy am I?
Amps add in parallel, volts add in series. Given your assumptions, you can put 45 of those 40Ah cells can produce 3.2v at 3600A if you arrange them in parallel, but 80 A at 144V if you arrange them in series. But you can't have your cake and eat it too and get 3600A at 144V... On Thu, Jul 24, 2014 at 5:37 PM, Ben Goren via EV ev@lists.evdl.org wrote: On Jul 22, 2014, at 8:21 AM, EVDL Administrator via EV ev@lists.evdl.org wrote: For example, the CALB 40ah cells I mentioned are rated for a maximum discharge of 2C (80 amps). At 144v, 80a is 11.5kW. Allowing for losses, that's only about 12hp from your motor! I think I may be a bit confused. If a single 40 Ah cell can provide 80 A (for a little while), shouldn't 45 of those 40 Ah cells be able to provide 80 A * 45 = 3600 A? That 80 A would be at 3.2 V for 256 W. All 45 cells would be at 144 V, for 518.4 kW or ~ 500 hp. That's three times the power of the 260 Windsor engine in the car today, and substantially more than you're going to get in a stock muscle car of any era -- and way more than even a pair of AC-50s or WarP 9s is rated for. So...does discharge scale with the number of batteries, or is it limited by the discharge of a single cell? If the former, I should be more than fine with a 45-cell pack of CALB 40 Ah batteries or equivalent. If the latter...I'm likely screwed Thanks, b -- next part -- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 801 bytes Desc: Message signed with OpenPGP using GPGMail URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140724/f9e034e8/attachment.pgp ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] How crazy am I?
Ben, I'm not an engineer but I don't think you can add up the amps in a series configuration. If the batteries are connected in series, the same current flows through all of them at the same time (it doesn't spread out the current load). Think of a chain is only as strong as its weakest link - in this case the whole string can only handle 80A amps. If you put 3600 amps through the pack each battery would get that same load at the same time and would fry them all spectacularly! - Peter Flipsen Jr On Thu, Jul 24, 2014 at 2:37 PM, Ben Goren via EV ev@lists.evdl.org wrote: On Jul 22, 2014, at 8:21 AM, EVDL Administrator via EV ev@lists.evdl.org wrote: For example, the CALB 40ah cells I mentioned are rated for a maximum discharge of 2C (80 amps). At 144v, 80a is 11.5kW. Allowing for losses, that's only about 12hp from your motor! I think I may be a bit confused. If a single 40 Ah cell can provide 80 A (for a little while), shouldn't 45 of those 40 Ah cells be able to provide 80 A * 45 = 3600 A? That 80 A would be at 3.2 V for 256 W. All 45 cells would be at 144 V, for 518.4 kW or ~ 500 hp. That's three times the power of the 260 Windsor engine in the car today, and substantially more than you're going to get in a stock muscle car of any era -- and way more than even a pair of AC-50s or WarP 9s is rated for. So...does discharge scale with the number of batteries, or is it limited by the discharge of a single cell? If the former, I should be more than fine with a 45-cell pack of CALB 40 Ah batteries or equivalent. If the latter...I'm likely screwed Thanks, b -- next part -- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 801 bytes Desc: Message signed with OpenPGP using GPGMail URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140724/f9e034e8/attachment.pgp ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA ( http://groups.yahoo.com/group/NEDRA) -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140724/500e1965/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] How crazy am I?
Ben, Are you putting the cells in series or in parallel? 45 cells in parallel will indeed allow you to draw 45 times as much current - but at the same voltage as a single cell (3.2V) 3600A still gives 11kW. If yo uare putting the cells in series, then each cell can only do as much currrent as a single cell and since all cells are stacked, that current runs through *all* the cells, so the same 80A through them all, but at 45 times the voltage of a single cell, so the same 11kW. It is real simple - each cell contributes a certain amount of power: 3.2V x 80A = 256W. So, 45 cells can do 45 times as much power: 45 x 256W = 11.5kW Depending how you wire those cells, they can increase the total voltage by stacking cells in series, or they can increase the current by wiring them in parallel, you can even create a mix of series/parallel, for example 3 strings of 15 series cells for 15 times higher voltage (48V) and 3 times higher current by adding up the currents through the 3 parallel strings for a total of 3x80A = 240A. 48V x 240A = 11.5kW because the power can never be more than the sum of what each cell can deliver... Hope this clarifies, Cor van de Water Chief Scientist Proxim Wireless Corporation http://www.proxim.com Email: cwa...@proxim.com Private: http://www.cvandewater.info Skype: cor_van_de_water Tel: +1 408 383 7626 -Original Message- From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of Ben Goren via EV Sent: Thursday, July 24, 2014 2:38 PM To: Electric Vehicle Discussion List Subject: Re: [EVDL] How crazy am I? On Jul 22, 2014, at 8:21 AM, EVDL Administrator via EV ev@lists.evdl.org wrote: For example, the CALB 40ah cells I mentioned are rated for a maximum discharge of 2C (80 amps). At 144v, 80a is 11.5kW. Allowing for losses, that's only about 12hp from your motor! I think I may be a bit confused. If a single 40 Ah cell can provide 80 A (for a little while), shouldn't 45 of those 40 Ah cells be able to provide 80 A * 45 = 3600 A? That 80 A would be at 3.2 V for 256 W. All 45 cells would be at 144 V, for 518.4 kW or ~ 500 hp. That's three times the power of the 260 Windsor engine in the car today, and substantially more than you're going to get in a stock muscle car of any era -- and way more than even a pair of AC-50s or WarP 9s is rated for. So...does discharge scale with the number of batteries, or is it limited by the discharge of a single cell? If the former, I should be more than fine with a 45-cell pack of CALB 40 Ah batteries or equivalent. If the latter...I'm likely screwed Thanks, b -- next part -- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 801 bytes Desc: Message signed with OpenPGP using GPGMail URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140724/f9e0 34e8/attachment.pgp ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] How crazy am I?
Thanks, Michael, Peter, and Cor. Your explanations are perfect. Now to do some more math and more research b On Jul 24, 2014, at 3:12 PM, Cor van de Water via EV ev@lists.evdl.org wrote: Ben, Are you putting the cells in series or in parallel? 45 cells in parallel will indeed allow you to draw 45 times as much current - but at the same voltage as a single cell (3.2V) 3600A still gives 11kW. If yo uare putting the cells in series, then each cell can only do as much currrent as a single cell and since all cells are stacked, that current runs through *all* the cells, so the same 80A through them all, but at 45 times the voltage of a single cell, so the same 11kW. It is real simple - each cell contributes a certain amount of power: 3.2V x 80A = 256W. So, 45 cells can do 45 times as much power: 45 x 256W = 11.5kW Depending how you wire those cells, they can increase the total voltage by stacking cells in series, or they can increase the current by wiring them in parallel, you can even create a mix of series/parallel, for example 3 strings of 15 series cells for 15 times higher voltage (48V) and 3 times higher current by adding up the currents through the 3 parallel strings for a total of 3x80A = 240A. 48V x 240A = 11.5kW because the power can never be more than the sum of what each cell can deliver... Hope this clarifies, Cor van de Water Chief Scientist Proxim Wireless Corporation http://www.proxim.com Email: cwa...@proxim.com Private: http://www.cvandewater.info Skype: cor_van_de_water Tel: +1 408 383 7626 -Original Message- From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of Ben Goren via EV Sent: Thursday, July 24, 2014 2:38 PM To: Electric Vehicle Discussion List Subject: Re: [EVDL] How crazy am I? On Jul 22, 2014, at 8:21 AM, EVDL Administrator via EV ev@lists.evdl.org wrote: For example, the CALB 40ah cells I mentioned are rated for a maximum discharge of 2C (80 amps). At 144v, 80a is 11.5kW. Allowing for losses, that's only about 12hp from your motor! I think I may be a bit confused. If a single 40 Ah cell can provide 80 A (for a little while), shouldn't 45 of those 40 Ah cells be able to provide 80 A * 45 = 3600 A? That 80 A would be at 3.2 V for 256 W. All 45 cells would be at 144 V, for 518.4 kW or ~ 500 hp. That's three times the power of the 260 Windsor engine in the car today, and substantially more than you're going to get in a stock muscle car of any era -- and way more than even a pair of AC-50s or WarP 9s is rated for. So...does discharge scale with the number of batteries, or is it limited by the discharge of a single cell? If the former, I should be more than fine with a 45-cell pack of CALB 40 Ah batteries or equivalent. If the latter...I'm likely screwed Thanks, b -- next part -- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 801 bytes Desc: Message signed with OpenPGP using GPGMail URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140724/f9e0 34e8/attachment.pgp ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) -- next part -- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 801 bytes Desc: Message signed with OpenPGP using GPGMail URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140724/d8b3b1f3/attachment.pgp ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] How crazy am I?
I have been looking at this, seemed to me that for the capacity, smaller batteries can discharge a higher current, I guess that's why Tesla uses 7000 small cells? R/C batteries are often rated at 90C or even greater, I have seen 300C. Look at this: http://www.hobbyking.com/hobbyking/store/__51838__Turnigy_nano_tech_Ultimate _6000mah_2S2P_90C_Hardcase_Lipo_Pack.html 6 Ah and 90C gives 540 Amps! From a 2 Cell battery you can wrap your hand around. -Original Message- From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of EVDL Administrator via EV Sent: Tuesday, 22 July 2014 8:21 p.m. To: Electric Vehicle Discussion List Subject: Re: [EVDL] How crazy am I? Another factor to consider is that while power capability varies by design, as a general rule, smaller cells are usually capable of lower power output. For example, the CALB 40ah cells I mentioned are rated for a maximum discharge of 2C (80 amps). At 144v, 80a is 11.5kW. Allowing for losses, that's only about 12hp from your motor! Not being a lithium expert, I don't know how much more than this you can actually draw before voltage sag really kicks in. But I'm pretty sure that pushing them too hard will shorten their lives significantly. If you expect sporty, Mustang-y EV performance, but don't want to carry around much of a battery, you'll need to find some cells designed for high power. The 90ah Winstons I mentioned are rated for only 1C continuous, but they say you can draw 10C for 10 seconds. It looks like you then need to allow at least 50 seconds of either zero or much lower current for the cell to recover (how often you can do this isn't clear from the spec). Other folks here may know how realistic this is, and/or have some recommendations for high power lithium cells. David Roden - Akron, Ohio, USA EVDL Administrator = = = = = = = = = = = = = = = = = = = = = = = = = = = = = EVDL Information: http://www.evdl.org/help/ = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Note: mail sent to evpost and etpost addresses will not reach me. To send a private message, please obtain my email address from the webpage http://www.evdl.org/help/ . = = = = = = = = = = = = = = = = = = = = = = = = = = = = = ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] How crazy am I?
On Jul 22, 2014, at 7:47 PM, EVDL Administrator via EV ev@lists.evdl.org wrote: On 22 Jul 2014 at 10:24, Ben Goren via EV wrote: Wikipedia says curb weight is 2,445. I don't see this ending up at 3,500 after conversion...but I also like estimating pessimistically. I see that too. But that's probably for an early 170 six with 3-speed stick and no options. Remember, in those days, even a radio was optional. I'm a bit young to remember those days...but, regardless, I'll go with your 3500 lbs after-conversion figure for estimating this stuff. Worst case, the car isn't that heavy and I wind up with more range and / or performance than expected. b -- next part -- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 801 bytes Desc: Message signed with OpenPGP using GPGMail URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140723/60fe0b2c/attachment.pgp ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] How crazy am I?
On Jul 23, 2014, at 3:45 AM, Ben Apollonio via EV ev@lists.evdl.org wrote: On the contrary. Tesla cells discharge at a very LOW current. When you have 85kWh of battery, you only need 3.5C to make 300kW, and C/5 to cruise at 55MPH. Even the 120kW 'supercharger' tops out at about 2C (for the smaller 60kWh battery). I would hazard this is why larger cells are not designed for large currents. RC cars are designed to run for 2 minutes and are trying to maximize power/weight. Most real world applications need more capacity and have to optimize energy/weight, so there's significantly less market for cells at 100Ah and 300C (not to mention that you would then have to find a way to manage 30,000 amps!!). You would seem to be correct. Judging by the battery packs I've found being sold for BEVs at the types of places listed as authorized dealers for Netgain and HPEVS, it looks like the assumption is that you're going to be throwing lots of batteries at the car so you don't need to worry much about individual battery discharge capability. I haven't by any stretch of the imagination done any sort of thorough investigation, but the first pass suggests that something along these lines might be the direction I'd have to head in: http://www.all-battery.com/tenergy3.2v1300mah4.16whlifepo4ifr18650prechargeablebattery-30065.aspx It's a single 18650-sized cell (Wikipedia says that's what the Tesla uses; looks to be a bit bigger than a AA) with a 1.35 Ah capacity. If my math is right, to get to ~10 kWh I'd need 1 kWh / (1.35 Ah * 3.2 V) ~= 2300 cells. Each cell supports up to 10 A continuous discharge...and 23,000 A is not only wy more than I'd need, it sounds positively terrifying. 2300 * 3.2 V ~= 7,400 V, which is again scary overkill -- and, obviously, they'd have to be wired in combinations of series and parallel banks to get that down to a reasonable range. Make the math easy, and do it as 50 packs of 45 batteries each for 144 V, 9.7 kWh, and don't think about it maximum current draw...and ~200 pounds of batteries. And about $9000 in batteries (almost 4x the cost of 144 V of CALB 40 Ah packs), before the cost of the hardware to wire them up and the time that would go into doing the wiring. At that point, what I was thinking of as the advantage of a small pack is long gone. This kind of a n homebrew system still might make more sense for this particular project than an off-the-shelf product, but it would mean a bunch of re-thinking Has anybody here already done this type of research? Is there a graceful way to get to high current capacity with a small pack size? Maybe a different size cell to build the packs from? I'm obviously not an expert on battery technology Thanks again, b -- next part -- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 801 bytes Desc: Message signed with OpenPGP using GPGMail URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140723/295e652d/attachment.pgp ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] How crazy am I?
David, I can corroborate your numbers on pack sizing. You pretty much summed up my conversion. I have 45 cells of ThunderSky 100Ah cells in a Honda del Sol for a nominal 144V pack and 13 kWh. In that car, I have a 50 mile range (barely). When new, I drove it 46 miles without issues, but I wouldn't try that on a regular basis. The car weighs 2550 pounds after electric conversion. I need a little more than 250 wh/mile with LRR tires and fairly conservative driving. From my experience, I would say your estimates for a hybrid conversion are quite close. My pack takes up about 1/2 the trunk (20 cells in 2 rows of 10) and two places under the hood (10 cells in front of the grill and 15 cells in front of the firewall along with the charger). See www.evalbum.com/2778 for more details and pictures. Mike On July 21, 2014 11:21:14 PM MDT, EVDL Administrator via EV ev@lists.evdl.org wrote: On 21 Jul 2014 at 14:12, Ben Goren via EV wrote: I'm really only looking for a battery pack big enough for local trips; a couple dozen miles would be plenty. I suspect that the smallest pack that puts out the necessary voltage is going to be just about the right size ... Hmm. Maybe. Let's do some math. A typical subcompact conversion uses around 250 Wh/mi. (Some have done as well as 150-160 Wh/mi, carefully driven.) You're not going to match that with a heavier, less aerodynamic car that wasn't designed with fuel efficiency in mind, however. What can you do? Well, in the EV Photo Album I found a '66 Mustang conversion that does 375 Wh/mi. http://www.evalbum.com/733 Here's a '65 ragtop that does 330 Wh/mi. That sounds a little better. http://www.evalbum.com/2056 One other similar Mustang entry estimated his energy use as at most 500 Wh/mi, but we'll take that with a grain of salt that since he doesn't seem to have measured it accurately yet. Now, these are BEV conversions. You're leaving in all the ICE bits for a car that will probably weigh in the 2800-3000lb range before conversion, maybe 3500 or more after. You'll might also pass up the skinny LRR tires for sticky high performance ones. So let's be conservative (and assume you probably won't drive like I do ;-) and allow 400 Wh/mi. You want about 25 miles of range. So you need 10 kWh, but you don't want to size your battery to that. You probably want to not exceed 80% DOD for good life, but let's say you're OK with giving up a little battery life, and go to 90%. So you actually need a battery capacity of about 11.1kWh. Doing that with lead in the space you have is going to be a non-starter, so I guess we'll go right to lithium. A LiFePO4 cell has a nominal voltage of 3.2v. Let's say you're going to use a 144v drive system, so you'll need 45 cells. (In a more reasonable world, you'd determine how much energy and power you need, and size the battery from that. THEN you'd decide what motor and controlller would work with that battery. However, we'll assume for now that you've already chosen a motor and controller, because it makes the calculations easier.) We'll start with, as you suggest, the smallest pack that puts out the necessary voltage. The laptop-size cells are obvously too small unless you go to massive paralleling a la Tesla, so let's jump to something like Headway 38140 cells. I'm no lithium expert, but I'd guess that these are about the smallest lithium cells practical for an EV (and a pretty light one at that). The 38140s are 12ah cells, 38mm in diameter and 152mm long. Because they're cylindrical, packaging isn't optimum, but (allowing a little wiggle room) a 5x9 matrix would be 152mm (6) high, 200mm (7.9) wide, and 360mm (14.2) long. Your battery box will need to be at least 25-50mm (1-2) larger in all dimensions than this, to allow for wiring, ventilation, and (in the winter) insulation. So you're looking at maybe 8h x 10w x 16l. I don't know how that compares to a banker's box, not being familiar with such a critter. Each cell is good for about 38.4 Wh, so 45 of them would be ... 1.73kWh. Hmm. That would get you about 4.3 miles of range. We're going to need something larger. How about CALB? The smallest one EVSource sells (that's not an endorsement, it's just one place I found offering them online) is 40ah. Each cell is 181mm x 115mm x 46mm. Again allowing a couple mm per cell for breathing room between (the lithium experts here can give you more info on whether this is necessary), your battery is now 181mm (7.1) high x 585mm (23) long x 432mm (17) wide. Again add at least 25-50mm (1-2) to each dimension to allow for battery box sizing, to get to around 9h x 25l by 19w, maybe even a little higher to allow for installing a BMS. Now with 45 cells we're talking 5.8kWh and a practical range of 13 miles with new cells, declining to perhaps 9.8 miles after a few years of use. Still only about half what you want. (But can you live with it?) Let's see
Re: [EVDL] How crazy am I?
Another factor to consider is that while power capability varies by design, as a general rule, smaller cells are usually capable of lower power output. For example, the CALB 40ah cells I mentioned are rated for a maximum discharge of 2C (80 amps). At 144v, 80a is 11.5kW. Allowing for losses, that's only about 12hp from your motor! Not being a lithium expert, I don't know how much more than this you can actually draw before voltage sag really kicks in. But I'm pretty sure that pushing them too hard will shorten their lives significantly. If you expect sporty, Mustang-y EV performance, but don't want to carry around much of a battery, you'll need to find some cells designed for high power. The 90ah Winstons I mentioned are rated for only 1C continuous, but they say you can draw 10C for 10 seconds. It looks like you then need to allow at least 50 seconds of either zero or much lower current for the cell to recover (how often you can do this isn't clear from the spec). Other folks here may know how realistic this is, and/or have some recommendations for high power lithium cells. David Roden - Akron, Ohio, USA EVDL Administrator = = = = = = = = = = = = = = = = = = = = = = = = = = = = = EVDL Information: http://www.evdl.org/help/ = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Note: mail sent to evpost and etpost addresses will not reach me. To send a private message, please obtain my email address from the webpage http://www.evdl.org/help/ . = = = = = = = = = = = = = = = = = = = = = = = = = = = = = ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] How crazy am I?
The discharge rate of the cells should play into the calculations as well. If the cells have a 3C max rate, 45 90 ah cells could produce about 52 HP (270 amps max@144v), resulting in a somewhat underpowered vehicle. How much does exceeding the discharge rate reduce the life of the pack? Is there a discharge rate that, once passed, makes the pack subject to random cell failures (i.e. more than 10C will damage the internal structure of a certain brand cell )? Tom Keenan On Jul 21, 2014, at 11:21 PM, EVDL Administrator via EV ev@lists.evdl.org wrote: On 21 Jul 2014 at 14:12, Ben Goren via EV wrote: I'm really only looking for a battery pack big enough for local trips; a couple dozen miles would be plenty. I suspect that the smallest pack that puts out the necessary voltage is going to be just about the right size ... Hmm. Maybe. Let's do some math. A typical subcompact conversion uses around 250 Wh/mi. (Some have done as well as 150-160 Wh/mi, carefully driven.) You're not going to match that with a heavier, less aerodynamic car that wasn't designed with fuel efficiency in mind, however. What can you do? Well, in the EV Photo Album I found a '66 Mustang conversion that does 375 Wh/mi. http://www.evalbum.com/733 Here's a '65 ragtop that does 330 Wh/mi. That sounds a little better. http://www.evalbum.com/2056 One other similar Mustang entry estimated his energy use as at most 500 Wh/mi, but we'll take that with a grain of salt that since he doesn't seem to have measured it accurately yet. Now, these are BEV conversions. You're leaving in all the ICE bits for a car that will probably weigh in the 2800-3000lb range before conversion, maybe 3500 or more after. You'll might also pass up the skinny LRR tires for sticky high performance ones. So let's be conservative (and assume you probably won't drive like I do ;-) and allow 400 Wh/mi. You want about 25 miles of range. So you need 10 kWh, but you don't want to size your battery to that. You probably want to not exceed 80% DOD for good life, but let's say you're OK with giving up a little battery life, and go to 90%. So you actually need a battery capacity of about 11.1kWh. Doing that with lead in the space you have is going to be a non-starter, so I guess we'll go right to lithium. A LiFePO4 cell has a nominal voltage of 3.2v. Let's say you're going to use a 144v drive system, so you'll need 45 cells. (In a more reasonable world, you'd determine how much energy and power you need, and size the battery from that. THEN you'd decide what motor and controlller would work with that battery. However, we'll assume for now that you've already chosen a motor and controller, because it makes the calculations easier.) We'll start with, as you suggest, the smallest pack that puts out the necessary voltage. The laptop-size cells are obvously too small unless you go to massive paralleling a la Tesla, so let's jump to something like Headway 38140 cells. I'm no lithium expert, but I'd guess that these are about the smallest lithium cells practical for an EV (and a pretty light one at that). The 38140s are 12ah cells, 38mm in diameter and 152mm long. Because they're cylindrical, packaging isn't optimum, but (allowing a little wiggle room) a 5x9 matrix would be 152mm (6) high, 200mm (7.9) wide, and 360mm (14.2) long. Your battery box will need to be at least 25-50mm (1-2) larger in all dimensions than this, to allow for wiring, ventilation, and (in the winter) insulation. So you're looking at maybe 8h x 10w x 16l. I don't know how that compares to a banker's box, not being familiar with such a critter. Each cell is good for about 38.4 Wh, so 45 of them would be ... 1.73kWh. Hmm. That would get you about 4.3 miles of range. We're going to need something larger. How about CALB? The smallest one EVSource sells (that's not an endorsement, it's just one place I found offering them online) is 40ah. Each cell is 181mm x 115mm x 46mm. Again allowing a couple mm per cell for breathing room between (the lithium experts here can give you more info on whether this is necessary), your battery is now 181mm (7.1) high x 585mm (23) long x 432mm (17) wide. Again add at least 25-50mm (1-2) to each dimension to allow for battery box sizing, to get to around 9h x 25l by 19w, maybe even a little higher to allow for installing a BMS. Now with 45 cells we're talking 5.8kWh and a practical range of 13 miles with new cells, declining to perhaps 9.8 miles after a few years of use. Still only about half what you want. (But can you live with it?) Let's see what we can do to get closer to your target range. The Winston WB- LYP90AHA is a 90ah cell. This will give you nearly 13kWh for a practical range of 29 miles, perhaps 22 miles as they age. Now we're talking. Each cell is 218mm high x 143mm long x 61mm wide.
Re: [EVDL] How crazy am I?
I would consider my ThunderSky cells as 1C normal draw with bursts of 2C or maybe a little more. I have rarely seen 3C even in the best conditions. If they are cold, don't even expect 2C. They work OK, but they are not a high performance pack. Mike On July 22, 2014 2:20:42 AM MDT, EVDL Administrator via EV ev@lists.evdl.org wrote: Another factor to consider is that while power capability varies by design, as a general rule, smaller cells are usually capable of lower power output. For example, the CALB 40ah cells I mentioned are rated for a maximum discharge of 2C (80 amps). At 144v, 80a is 11.5kW. Allowing for losses, that's only about 12hp from your motor! Not being a lithium expert, I don't know how much more than this you can actually draw before voltage sag really kicks in. But I'm pretty sure that pushing them too hard will shorten their lives significantly. If you expect sporty, Mustang-y EV performance, but don't want to carry around much of a battery, you'll need to find some cells designed for high power. The 90ah Winstons I mentioned are rated for only 1C continuous, but they say you can draw 10C for 10 seconds. It looks like you then need to allow at least 50 seconds of either zero or much lower current for the cell to recover (how often you can do this isn't clear from the spec). Other folks here may know how realistic this is, and/or have some recommendations for high power lithium cells. David Roden - Akron, Ohio, USA EVDL Administrator = = = = = = = = = = = = = = = = = = = = = = = = = = = = = EVDL Information: http://www.evdl.org/help/ = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Note: mail sent to evpost and etpost addresses will not reach me. To send a private message, please obtain my email address from the webpage http://www.evdl.org/help/ . = = = = = = = = = = = = = = = = = = = = = = = = = = = = = ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] How crazy am I?
I assumed people know, but guess I should specifically point out that ThunderSky is the previous name for the company now known as Winston. I don't know how much their chemistry varies between the two company names. My cells are more than 4 years old, so it is quite possible for new cells to be improved over mine. Mike On July 22, 2014 2:20:42 AM MDT, EVDL Administrator via EV ev@lists.evdl.org wrote: Another factor to consider is that while power capability varies by design, as a general rule, smaller cells are usually capable of lower power output. For example, the CALB 40ah cells I mentioned are rated for a maximum discharge of 2C (80 amps). At 144v, 80a is 11.5kW. Allowing for losses, that's only about 12hp from your motor! Not being a lithium expert, I don't know how much more than this you can actually draw before voltage sag really kicks in. But I'm pretty sure that pushing them too hard will shorten their lives significantly. If you expect sporty, Mustang-y EV performance, but don't want to carry around much of a battery, you'll need to find some cells designed for high power. The 90ah Winstons I mentioned are rated for only 1C continuous, but they say you can draw 10C for 10 seconds. It looks like you then need to allow at least 50 seconds of either zero or much lower current for the cell to recover (how often you can do this isn't clear from the spec). Other folks here may know how realistic this is, and/or have some recommendations for high power lithium cells. David Roden - Akron, Ohio, USA EVDL Administrator = = = = = = = = = = = = = = = = = = = = = = = = = = = = = EVDL Information: http://www.evdl.org/help/ = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Note: mail sent to evpost and etpost addresses will not reach me. To send a private message, please obtain my email address from the webpage http://www.evdl.org/help/ . = = = = = = = = = = = = = = = = = = = = = = = = = = = = = ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] How crazy am I?
On 07/22/2014 08:29 AM, Mike Nickerson via EV wrote: I would consider my ThunderSky cells as 1C normal draw with bursts of 2C or maybe a little more. I have rarely seen 3C even in the best conditions. If they are cold, don't even expect 2C. With my ~2008 vintage TS-LFP260s, I can pull at least 800 amps in warm conditions without creating low voltage events. I would guess well over 10 seconds though the limiting factor is how fast you end up going rather than voltage sag. At temperatures of around 40 deg and below, they do start alarming at around 1C, 200-300 amps. ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] How crazy am I?
On Jul 21, 2014, at 10:21 PM, EVDL Administrator via EV ev@lists.evdl.org wrote: On 21 Jul 2014 at 14:12, Ben Goren via EV wrote: I'm really only looking for a battery pack big enough for local trips; a couple dozen miles would be plenty. I suspect that the smallest pack that puts out the necessary voltage is going to be just about the right size ... Hmm. Maybe. Let's do some math. Thanks -- this really, really helps! You're leaving in all the ICE bits for a car that will probably weigh in the 2800-3000lb range before conversion, maybe 3500 or more after. Wikipedia says curb weight is 2,445. I don't see this ending up at 3,500 after conversion...but I also like estimating pessimistically. You'll might also pass up the skinny LRR tires for sticky high performance ones. Yes, likely -- especially if this winds up being the type of performance vehicle I suspect it might. I'm thinking bicycle tires on something with this much torque and power likely would only increase my chances for a Darwin award How about CALB? The smallest one EVSource sells (that's not an endorsement, it's just one place I found offering them online) is 40ah. That's actually what I was using for my own back-of-the-envelope calculations, but from EVWest's site. Each cell is 181mm x 115mm x 46mm. Again allowing a couple mm per cell for breathing room between (the lithium experts here can give you more info on whether this is necessary), your battery is now 181mm (7.1) high x 585mm (23) long x 432mm (17) wide. Again add at least 25-50mm (1-2) to each dimension to allow for battery box sizing, to get to around 9h x 25l by 19w, maybe even a little higher to allow for installing a BMS. That's again about what I came up with. A banker's box is one of those cardboard boxes that acts as a portable filing cabinet, mostly to store documents in a warehouse. It's about 10 x 12 x 15 -- a bit smaller, but not hugely. Now with 45 cells we're talking 5.8kWh and a practical range of 13 miles with new cells, declining to perhaps 9.8 miles after a few years of use. Still only about half what you want. (But can you live with it?) I had roughly guesstimated a bit less than twice that range...considering you're assuming worse efficiency than I had been guessing at, that puts the numbers in the same ballpark. Especially considering that press release posted here earlier this morning about, in that example, LG planning 200 mile packs in a couple years, I'm starting to think that it might not be such a terrible idea to start with a smaller pack that's merely good enough and figure on upgrading as battery technology improves. Those 45 of those CALB 40 Ah batteries are going to cost about $2500. If I planned on replacing them in 4 - 5 years with something that cost as much but had significantly more capacity, that'd work out to about the cost of a tank of gas per month. If I could put those batteries to good use at their end of life (I'm guessing they wouldn't have much resale value), that'd further mitigate that cost. Sticking with our 5 x 9 configuration, we now have 218mm (8.6) x 1100mm (43) x 567mm (22.3) for a battery box about 11h x 45w x 24d. ...or about one by two by four feet. Would there be enough room for this battery in the forward part of the trunk, between the wheel wells and above the rear axle? Possibly...but something like that might make sense as a pair of, say, one by two by two feet blocks at the outside edge of the trunk, or even four one by one by two blocks at the four corners of the car -- the engine compartment has lots of empty space in it. Or split the difference between the pack sizes, or some other variation on the theme. Regardless, the math seems to show that the physical dimensions of the batteries aren't going to be a show-stopper, which I think is the most important thing for me to worry about with this type of exercise at this stage. Thanks again for the help! b -- next part -- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 801 bytes Desc: Message signed with OpenPGP using GPGMail URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140722/ee3b1147/attachment.pgp ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] How crazy am I?
On Tue Jul 22 10:24:59 PDT 2014 ev@lists.evdl.org said: How about CALB? The smallest one EVSource sells (that's not an endorsement, it's just one place I found offering them online) is 40ah. That's actually what I was using for my own back-of-the-envelope calculations, but from EVWest's site. Have you thought about Leaf modules? That's what I'm using in my truck. http://hybridautocenter.com/HAC4/index.php?option=com_hikashopctrl=producttask=showcid=4name=new-11kw-h-battery-block-182v-60ahItemid=605 -- Try my Sensible Email package! https://sourceforge.net/projects/sensibleemail/ ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] How crazy am I?
On Jul 22, 2014, at 1:20 AM, EVDL Administrator via EV ev@lists.evdl.org wrote: Another factor to consider is that while power capability varies by design, as a general rule, smaller cells are usually capable of lower power output. Um. I was unaware that that was something that needed to be taken into consideration. Is that a matter of heat dissipation, and therefore something that'd get worse in summer and be helped with active cooling? Or does it have more to do with chemistry, or...? b -- next part -- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 801 bytes Desc: Message signed with OpenPGP using GPGMail URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140722/4ab9662b/attachment.pgp ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] How crazy am I?
On 07/22/2014 12:33 PM, John Lussmyer via EV wrote: Have you thought about Leaf modules? That's what I'm using in my truck. http://hybridautocenter.com/HAC4/index.php?option=com_hikashopctrl=producttask=showcid=4name=new-11kw-h-battery-block-182v-60ahItemid=605 -- Try my What are the BMS options for the Leaf modules? ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] How crazy am I?
Ben, Consider the Micro-hybrid with a electric motorcycle motor belt driven from a belt from the harmonic balancer in the front end of the crank of the ICE and placed in the location of the original alternator. The electric motor is used to start the ICE after pausing and eliminates the need to idle saving fuel. Also the motor gives a boost when accelerating from a stop, minimising extra fuel consumption when starting out. The battery pack need be only 48V. and recharged by the motor acting as a generator. A 25 HP AC motor can do: starting, charging, power boost, and with a DC/DC charge the 12V battery too. And it will cost less and be more easily fit in the Mustang. Then when you restore the Mustang to sell it, you can use the motorcycle motor, controller, and batteries, you can make a yard tractor, atv, or motorcycle into an electric. Dennis Lee Miles (EVprofessor) *Founder:**EV Tech. Institute Inc.** (www.evti.org http://www.evti.org) * *You Tube Video Link: http://youtu.be/T-FVjMRVLss http://youtu.be/T-FVjMRVLss * *E-Mail:* *evprofes...@evprofessor.com* evprofes...@evprofessor.com *Phone #* *(863) 944-9913* in Central Florida (Office hours: 12:00 Noon to 10:00 pm, New York time) On Tue, Jul 22, 2014 at 1:24 PM, Ben Goren via EV ev@lists.evdl.org wrote: On Jul 21, 2014, at 10:21 PM, EVDL Administrator via EV ev@lists.evdl.org wrote: On 21 Jul 2014 at 14:12, Ben Goren via EV wrote: I'm really only looking for a battery pack big enough for local trips; a couple dozen miles would be plenty. I suspect that the smallest pack that puts out the necessary voltage is going to be just about the right size ... Hmm. Maybe. Let's do some math. Thanks -- this really, really helps! You're leaving in all the ICE bits for a car that will probably weigh in the 2800-3000lb range before conversion, maybe 3500 or more after. Wikipedia says curb weight is 2,445. I don't see this ending up at 3,500 after conversion...but I also like estimating pessimistically. You'll might also pass up the skinny LRR tires for sticky high performance ones. Yes, likely -- especially if this winds up being the type of performance vehicle I suspect it might. I'm thinking bicycle tires on something with this much torque and power likely would only increase my chances for a Darwin award How about CALB? The smallest one EVSource sells (that's not an endorsement, it's just one place I found offering them online) is 40ah. That's actually what I was using for my own back-of-the-envelope calculations, but from EVWest's site. Each cell is 181mm x 115mm x 46mm. Again allowing a couple mm per cell for breathing room between (the lithium experts here can give you more info on whether this is necessary), your battery is now 181mm (7.1) high x 585mm (23) long x 432mm (17) wide. Again add at least 25-50mm (1-2) to each dimension to allow for battery box sizing, to get to around 9h x 25l by 19w, maybe even a little higher to allow for installing a BMS. That's again about what I came up with. A banker's box is one of those cardboard boxes that acts as a portable filing cabinet, mostly to store documents in a warehouse. It's about 10 x 12 x 15 -- a bit smaller, but not hugely. Now with 45 cells we're talking 5.8kWh and a practical range of 13 miles with new cells, declining to perhaps 9.8 miles after a few years of use. Still only about half what you want. (But can you live with it?) I had roughly guesstimated a bit less than twice that range...considering you're assuming worse efficiency than I had been guessing at, that puts the numbers in the same ballpark. Especially considering that press release posted here earlier this morning about, in that example, LG planning 200 mile packs in a couple years, I'm starting to think that it might not be such a terrible idea to start with a smaller pack that's merely good enough and figure on upgrading as battery technology improves. Those 45 of those CALB 40 Ah batteries are going to cost about $2500. If I planned on replacing them in 4 - 5 years with something that cost as much but had significantly more capacity, that'd work out to about the cost of a tank of gas per month. If I could put those batteries to good use at their end of life (I'm guessing they wouldn't have much resale value), that'd further mitigate that cost. Sticking with our 5 x 9 configuration, we now have 218mm (8.6) x 1100mm (43) x 567mm (22.3) for a battery box about 11h x 45w x 24d. ...or about one by two by four feet. Would there be enough room for this battery in the forward part of the trunk, between the wheel wells and above the rear axle? Possibly...but something like that might make sense as a pair of, say, one by two by two feet blocks at the outside edge of the trunk, or even four one by one by two blocks at the four corners of the car -- the engine compartment has lots of empty space in it.
Re: [EVDL] How crazy am I?
On 22 Jul 2014 at 10:24, Ben Goren via EV wrote: Wikipedia says curb weight is 2,445. I don't see this ending up at 3,500 after conversion...but I also like estimating pessimistically. I see that too. But that's probably for an early 170 six with 3-speed stick and no options. Remember, in those days, even a radio was optional. In the same article, I read 2570 lb for a 1965 6-cylinder, and 3000 lb for a fully equipped V8 model. That seems like more difference than I'd expect for a 260 or 289 vs a 170 or 200, but I suppose they'd have beefed up other drivetrain components. The designers were working this all out by hand - they had no computer modeling in those days. They also apparently had some early problems with excessive body flexing, so stiffening the body probably added some weight. Another factor to consider is that while power capability varies by design, as a general rule, smaller cells are usually capable of lower power output. Um. I was unaware that that was something that needed to be taken into consideration. Is that a matter of heat dissipation, and therefore something that'd get worse in summer and be helped with active cooling? Or does it have more to do with chemistry, or...? It's a design decision, I guess. In lead batteries you're balancing cost, cycle life, specific power, and specific energy. You can't optimize for all of them at once. I would think that lithium battery designers make similar tradeoffs. David Roden - Akron, Ohio, USA EVDL Administrator = = = = = = = = = = = = = = = = = = = = = = = = = = = = = EVDL Information: http://www.evdl.org/help/ = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Note: mail sent to evpost and etpost addresses will not reach me. To send a private message, please obtain my email address from the webpage http://www.evdl.org/help/ . = = = = = = = = = = = = = = = = = = = = = = = = = = = = = ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] How crazy am I?
David, Thanks for your detailed and thoughtful analysis! I *think* I'm dodging most of the worst pitfalls you caution against. Specifically: The result is that your hybrid isn't going to be optimized as either an ICEV or an EV. It's likely that its EV range will be less than a similar BEV's, and its fuel efficiency less than a similar ICEV's. It's a very safe bet that you're spot on...but, as wonderful as fuel economy is, that's actually something that I think is reasonably quite far down the list on this particular project. The EV's efficiency is most important in terms of range and battery pack size (and therefore cost, volume, weight, etc.) and secondarily in terms of cents per mile. The ICEV's efficiency is pretty much all about cents per mile. For this project, I'm really only looking for a battery pack big enough for local trips; a couple dozen miles would be plenty. I suspect that the smallest pack that puts out the necessary voltage is going to be just about the right size, even with those batteries having to lug around all the extra weight of the combustion engine and transmission and fuel and the like. And, even if it's right on the edge of being enough for some particular trip, having to use the combustion engine for the last mile or two of a twenty-mile trip really isn't a big deal. So, for practical reasons, electric economy isn't (much of) a concern. For financial reasons...well, I'm already generating so much surplus electricity from my solar roof that the electricity for the vehicle is going to be free, pretty much regardless -- and, again, even if I have to buy the last couple kWh or so from the utility, that's again a rounding error. The combustion engine's efficiency when working alone will certainly suffer, both from the added weight of the electric motor system and from having to spin them. However, I don't anticipate ever wanting to use only the combustion engine in isolation (save for emergencies). Rather, I'd use the electric motor as a traditional Prius-style hybrid, for acceleration and regenerative braking; that alone should significantly more than make up for any losses introduced into the system. Will it be as efficient as a new car, especially a new hybrid? Not even close. But it'll be a lot more efficient than a classic Mustang, and the total efficiency (when considering all-electric driving) will be so insanely more efficient that, again, the fact that it doesn't do so great in an absolute sense in certain limited situations isn't going to be worth worrying about. From what I can see, it's (not surprisingly) any hybrid is tougher and more expensive than a straight BEV conversion. I think this is especially true of a parallel hybrid, because you have somewhat less flexibility in positioning components. This has certainly been a big challenge in getting to this point. The initial thought was something mounted in place of the generator, then something mounted to the front of the crankshaft. But I *think* it's (potentially) solved with the direct-drive configuration. Even if the tunnel has to be enlarged a bit, there's about 50 of driveshaft in the car that's nothing but a spinning rod. Replacing a passive linkage with something that provides power makes a lot of sense to me, and there's the physical room to fit it in. That still leaves the question of where to put the controllers and the batteries, but I'm less concerned about that. The controllers aren't all that big, and likely would even fit under a seat. The batteries would need more room...but I don't think the battery pack is going to be much larger than a banker's box, and I can certainly spare that much volume from the trunk. (One possibly more flexible parallel hybrid variant is the through the road hybrid, where you drive the front wheels with one fuel and the rear wheels with another.) I've investigated this, too. Using HPEVS- or NetGain-style motors to provide power to the front wheels...I just don't see that happening. That leaves hub wheel motors, and all the ones I've found that are readily available (and not solely the plaything of a research lab somewhere) aren't anywhere near powerful enough for a car the weight of a Mustang. If I'm mistraken on that and there really are hub wheel motors available that would work, that would be a *very* attractive option to consider. But a pair such wheels would have to be at least as powerful as an AC-35 or Warp 9, and I've not found such a beast. To get a final result that's as efficient and as seamless as one where a team of automotive engineers designed it (Volt or Plug-in Prius), you probably need to have some automotive engineer chops yourself. Agreed -- and, fortunately, I'm not looking for something with the efficiency or engineering elegance of those cars, and I don't mind throwing a bit of brute force at the job (such as a pair of AC-50s) in lieu of sophistication. Just remember
Re: [EVDL] How crazy am I?
On Jul 19, 2014, at 2:58 PM, Dennis Miles via EV ev@lists.evdl.org wrote: On the question, I have an opinion. The only very successful Real Hybrid conversions have been those which replace the ICE with a smaller unit and transmission and added an Electric (AC) Motor. May I ask...what do you mean by both real and successful...? The latter, particularly...not every project has the same goals for success, and something that one person might consider a complete waste would be the ideal solution for another. Witness most commercial EVs on the road today; many people would call them overpriced and so lacking in range as to be toys, yet many people reading these words can't imagine going back to burning gasoline. b -- next part -- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 801 bytes Desc: Message signed with OpenPGP using GPGMail URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140721/3f7e7c41/attachment.pgp ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] How crazy am I?
On 21 Jul 2014 at 14:12, Ben Goren via EV wrote: I'm really only looking for a battery pack big enough for local trips; a couple dozen miles would be plenty. I suspect that the smallest pack that puts out the necessary voltage is going to be just about the right size ... Hmm. Maybe. Let's do some math. A typical subcompact conversion uses around 250 Wh/mi. (Some have done as well as 150-160 Wh/mi, carefully driven.) You're not going to match that with a heavier, less aerodynamic car that wasn't designed with fuel efficiency in mind, however. What can you do? Well, in the EV Photo Album I found a '66 Mustang conversion that does 375 Wh/mi. http://www.evalbum.com/733 Here's a '65 ragtop that does 330 Wh/mi. That sounds a little better. http://www.evalbum.com/2056 One other similar Mustang entry estimated his energy use as at most 500 Wh/mi, but we'll take that with a grain of salt that since he doesn't seem to have measured it accurately yet. Now, these are BEV conversions. You're leaving in all the ICE bits for a car that will probably weigh in the 2800-3000lb range before conversion, maybe 3500 or more after. You'll might also pass up the skinny LRR tires for sticky high performance ones. So let's be conservative (and assume you probably won't drive like I do ;-) and allow 400 Wh/mi. You want about 25 miles of range. So you need 10 kWh, but you don't want to size your battery to that. You probably want to not exceed 80% DOD for good life, but let's say you're OK with giving up a little battery life, and go to 90%. So you actually need a battery capacity of about 11.1kWh. Doing that with lead in the space you have is going to be a non-starter, so I guess we'll go right to lithium. A LiFePO4 cell has a nominal voltage of 3.2v. Let's say you're going to use a 144v drive system, so you'll need 45 cells. (In a more reasonable world, you'd determine how much energy and power you need, and size the battery from that. THEN you'd decide what motor and controlller would work with that battery. However, we'll assume for now that you've already chosen a motor and controller, because it makes the calculations easier.) We'll start with, as you suggest, the smallest pack that puts out the necessary voltage. The laptop-size cells are obvously too small unless you go to massive paralleling a la Tesla, so let's jump to something like Headway 38140 cells. I'm no lithium expert, but I'd guess that these are about the smallest lithium cells practical for an EV (and a pretty light one at that). The 38140s are 12ah cells, 38mm in diameter and 152mm long. Because they're cylindrical, packaging isn't optimum, but (allowing a little wiggle room) a 5x9 matrix would be 152mm (6) high, 200mm (7.9) wide, and 360mm (14.2) long. Your battery box will need to be at least 25-50mm (1-2) larger in all dimensions than this, to allow for wiring, ventilation, and (in the winter) insulation. So you're looking at maybe 8h x 10w x 16l. I don't know how that compares to a banker's box, not being familiar with such a critter. Each cell is good for about 38.4 Wh, so 45 of them would be ... 1.73kWh. Hmm. That would get you about 4.3 miles of range. We're going to need something larger. How about CALB? The smallest one EVSource sells (that's not an endorsement, it's just one place I found offering them online) is 40ah. Each cell is 181mm x 115mm x 46mm. Again allowing a couple mm per cell for breathing room between (the lithium experts here can give you more info on whether this is necessary), your battery is now 181mm (7.1) high x 585mm (23) long x 432mm (17) wide. Again add at least 25-50mm (1-2) to each dimension to allow for battery box sizing, to get to around 9h x 25l by 19w, maybe even a little higher to allow for installing a BMS. Now with 45 cells we're talking 5.8kWh and a practical range of 13 miles with new cells, declining to perhaps 9.8 miles after a few years of use. Still only about half what you want. (But can you live with it?) Let's see what we can do to get closer to your target range. The Winston WB- LYP90AHA is a 90ah cell. This will give you nearly 13kWh for a practical range of 29 miles, perhaps 22 miles as they age. Now we're talking. Each cell is 218mm high x 143mm long x 61mm wide. Sticking with our 5 x 9 configuration, we now have 218mm (8.6) x 1100mm (43) x 567mm (22.3) for a battery box about 11h x 45w x 24d. This is a significant distance from the smallest pack that puts out the necessary voltage, unfortunately, but still smaller than a lead pack would be. The specs in Wikipedia say the Mustang Mk I is about 68 wide. Would there be enough room for this battery in the forward part of the trunk, between the wheel wells and above the rear axle? I'm thinking that otherwise you'd lose a fair bit of trunk space. Or maybe you could fit a half-size gas tank, and use some of the freed-up space for part of the
Re: [EVDL] How crazy am I?
Someone on this list did a Ford F-350 IIRC and I am not sure if that was a straight EV, my memory seems to suggest that he added an electric motor in between engine and driveshaft (transmission?), just like you are planning. I believe it was one of the Johns on this list, forgot which one. Cor van de Water Chief Scientist Proxim Wireless Corporation http://www.proxim.com Email: cwa...@proxim.com Private: http://www.cvandewater.info Skype: cor_van_de_water Tel: +1 408 383 7626 -Original Message- From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of Ben Goren via EV Sent: Monday, July 21, 2014 2:12 PM To: EVDL Administrator; Electric Vehicle Discussion List Subject: Re: [EVDL] How crazy am I? David, Thanks for your detailed and thoughtful analysis! I *think* I'm dodging most of the worst pitfalls you caution against. Specifically: The result is that your hybrid isn't going to be optimized as either an ICEV or an EV. It's likely that its EV range will be less than a similar BEV's, and its fuel efficiency less than a similar ICEV's. It's a very safe bet that you're spot on...but, as wonderful as fuel economy is, that's actually something that I think is reasonably quite far down the list on this particular project. The EV's efficiency is most important in terms of range and battery pack size (and therefore cost, volume, weight, etc.) and secondarily in terms of cents per mile. The ICEV's efficiency is pretty much all about cents per mile. For this project, I'm really only looking for a battery pack big enough for local trips; a couple dozen miles would be plenty. I suspect that the smallest pack that puts out the necessary voltage is going to be just about the right size, even with those batteries having to lug around all the extra weight of the combustion engine and transmission and fuel and the like. And, even if it's right on the edge of being enough for some particular trip, having to use the combustion engine for the last mile or two of a twenty-mile trip really isn't a big deal. So, for practical reasons, electric economy isn't (much of) a concern. For financial reasons...well, I'm already generating so much surplus electricity from my solar roof that the electricity for the vehicle is going to be free, pretty much regardless -- and, again, even if I have to buy the last couple kWh or so from the utility, that's again a rounding error. The combustion engine's efficiency when working alone will certainly suffer, both from the added weight of the electric motor system and from having to spin them. However, I don't anticipate ever wanting to use only the combustion engine in isolation (save for emergencies). Rather, I'd use the electric motor as a traditional Prius-style hybrid, for acceleration and regenerative braking; that alone should significantly more than make up for any losses introduced into the system. Will it be as efficient as a new car, especially a new hybrid? Not even close. But it'll be a lot more efficient than a classic Mustang, and the total efficiency (when considering all-electric driving) will be so insanely more efficient that, again, the fact that it doesn't do so great in an absolute sense in certain limited situations isn't going to be worth worrying about. From what I can see, it's (not surprisingly) any hybrid is tougher and more expensive than a straight BEV conversion. I think this is especially true of a parallel hybrid, because you have somewhat less flexibility in positioning components. This has certainly been a big challenge in getting to this point. The initial thought was something mounted in place of the generator, then something mounted to the front of the crankshaft. But I *think* it's (potentially) solved with the direct-drive configuration. Even if the tunnel has to be enlarged a bit, there's about 50 of driveshaft in the car that's nothing but a spinning rod. Replacing a passive linkage with something that provides power makes a lot of sense to me, and there's the physical room to fit it in. That still leaves the question of where to put the controllers and the batteries, but I'm less concerned about that. The controllers aren't all that big, and likely would even fit under a seat. The batteries would need more room...but I don't think the battery pack is going to be much larger than a banker's box, and I can certainly spare that much volume from the trunk. (One possibly more flexible parallel hybrid variant is the through the road hybrid, where you drive the front wheels with one fuel and the rear wheels with another.) I've investigated this, too. Using HPEVS- or NetGain-style motors to provide power to the front wheels...I just don't see that happening. That leaves hub wheel motors, and all the ones I've found that are readily available (and not solely the plaything of a research lab somewhere) aren't anywhere near powerful enough for a car the weight of a Mustang. If I'm mistraken on that and there really are hub
Re: [EVDL] How crazy am I?
Ben, Sounds like a fun project that surely would be possible. Probably complex, but surely possible! I can comment about owning a conversion in Phoenix as this is the third summer I've had my EV on the road (http://evalbum.com/2358). My pack is large, 45x CALB 180's and is in the trunk. I just installed some temperature sensors in between cells in a few places in my pack before this summer started. Some observations during the summer: - Driving 50 miles straight (about half the pack capacity) causes a temperature rise of about 15F - When parked in the sun all day while at work, cell temp is usually about equal to the forecasted high for that day. - When parked in the sun all day with a car cover, cell temp is still usually about equal to the forecasted high for that day (but the cabin is a bit cooler!) - The next morning after parking the car outside, the cell temps read about 5F above the forecasted low. - My charger is in the trunk which has just a few holes to passively let air in/out. When charging overnight, the cell temp the next morning has only dropped a few degrees from the previous day's forecasted high. - If I crack open the trunk at night and put in a small computer muffin fan to circulate air inside, cell temps read equivalent to the forecasted low the next morning. - My cells are grouped in a large bank of 33 cells (3x11) and two small banks of 6. The two small banks seem to cool faster likely because they have more exposed surface area. They are cooler in the morning than the large bank. - It's tough to measure, but I think I've lost about 10-12% capacity in 3 years so far. I'm sure the heat plays a role in that. A friend of mine here converted a porsche with 70 cells of CALB 60's, about half the capacity of my pack. His cells are exposed to ambient air so he gets some passive cooling during driving. He typically sees about a 10F rise above ambient. Take from this what you will, but my conclusions are that active cooling would be minimally effective in lowering the temperature of a large mass of batteries for the short amount of time you'd be driving. This is especially true since presumably you won't be cooling the cells while the car is parked. If I were to rebuild my pack, I'd probably space out the bank of 33 cells to expose some more surface area. I'd also automate a vent fan that cooled that pack down at night by drawing in outside air and I'd change the charger cooling scheme so it wasn't dumping heat into the same space as the batteries. Joe On Mon, Jul 21, 2014 at 2:16 PM, Ben Goren via EV ev@lists.evdl.org wrote: On Jul 19, 2014, at 2:58 PM, Dennis Miles via EV ev@lists.evdl.org wrote: On the question, I have an opinion. The only very successful Real Hybrid conversions have been those which replace the ICE with a smaller unit and transmission and added an Electric (AC) Motor. May I ask...what do you mean by both real and successful...? The latter, particularly...not every project has the same goals for success, and something that one person might consider a complete waste would be the ideal solution for another. Witness most commercial EVs on the road today; many people would call them overpriced and so lacking in range as to be toys, yet many people reading these words can't imagine going back to burning gasoline. b -- next part -- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 801 bytes Desc: Message signed with OpenPGP using GPGMail URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140721/3f7e7c41/attachment.pgp ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA ( http://groups.yahoo.com/group/NEDRA) -- next part -- An HTML attachment was scrubbed... URL: http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140721/1c3535f9/attachment.htm ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] How crazy am I?
On Mon Jul 21 22:23:18 PDT 2014 ev@lists.evdl.org said: Someone on this list did a Ford F-350 IIRC and I am not sure if that was a straight EV, my memory seems to suggest that he added an electric motor in between engine and driveshaft (transmission?), just like you are planning. I believe it was one of the Johns on this list, forgot which one. I have a pure EV Ford F-250. -- Worlds only All Electric F-250 truck! http://john.casadelgato.com/Electric-Vehicles/1995-Ford-F-250 ___ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
Re: [EVDL] How crazy am I?
Hi Ben, I'm a little surprised at the light response you've gotten to your question. I would have thought there'd be more folks here who at least have put some thought into homebrewing a hybrid this way, if not done it themselves. So, even though I'm about the worst person to do so since I'm a EE dropout and have never built a hybrid, I'll post a few random ideas about them that have popped into my head over the years. First, some thoughts on why or why not. ICEVs' efficiency has improved immensely from microprocessor engine control, but it's still pretty abysmal on short trips. For some folks, short trips can amount to a lot of driving - take the kids to school, come home, run to the store, come home, pick the kids up, come home ... repeat to 40 or 50 significant digits. That kind of use is also hard on an ICE, because it never gets properly warmed up. OTOH, EVs excel at short trips. They don't need to warm up, they don't idle, and many have regen to claw back some kinetic energy normally wasted as heat in the brakes.. For folks who need to make both short and long trips, intuitively the true hybrid seems like an ideal compromise. However, the devil is in that little word, compromise. It's because you have two vehicles in one. To stick with conversions here, you're in effect doing a full EV conversion, but still leaving the engine and all its supporting hardware in place. You have to find a place to mount the EV drive components and the battery; but unlike a BEV conversion, you don't have nice big chunks of space where the ICE and gas tank used to be. So you have a packaging challenge. Your vehicle also gains a fair bit of weight. And there are other little places where you miss out on efficiency. For example, with the exhaust still there, you probably can't add a belly pan to smooth out the underbody aerodynamics, as you could with a BEV. The result is that your hybrid isn't going to be optimized as either an ICEV or an EV. It's likely that its EV range will be less than a similar BEV's, and its fuel efficiency less than a similar ICEV's. So after thinking all this over, I've decided that I'm more in favor of having multiple vehicles. Each can be optimized for different needs - an EV for local trips, and an ICEV for long trips, for example. This is a great solution where you have two drivers and two cars. With just one driver, I guess it depends partly on what it costs to license and insure two vehicles in your area. I also really like the station car concept, where you commute using mass transit, and lease an EV for daily use between your house and the train station. In the best of these proposals, you can also swap your EV for an ICEV car or van or truck, when you need that instead (you want to go on vacation with the kids, or to fetch a load of lumber). Alas, I don't see many of these on the horizon. Not that I'm trying to talk you out of this project, just presenting some things to consider. Now, again, I'm not really the right person to advise you. But maybe if I cast out some ideas here, someone else will pop up and disagree with me ;-) First a little of my somewhat quirky nomenclature. I'm an old guy, so hybrid still means to me what it meant in 1969. To me, a hybrid is a vehicle that can use multiple energy sources. The cars most folks call hybrids today get all their energy from gasoline. Others here disagree with me on this point, which is fine, but I don't consider a car like a non-plug-in Prius a true hybrid. In my book, most of the factory hybrids are really ICEVs with electric superchargers and/or sophisticated transmissions. The Prius power splitting device is a really clever gadget that amounts to an electomechanical torque converter, for example. So let me use the term true hybrid here for the real stuff. You may already know this, but true hybrids come in two flavors, series and parallel. A series hybrid has its motor (only) permanently linked to the driveline. The ICE drives a generator or alternator that supplements or replaces the battery's energy. Diesel-electric locomotives are series hybrids. The downside of the series hybrid is that you lose some efficiency in the conversion of mechanical energy to electrical energy. Back in the 1960s and 1970s, before the days of microprocessor ICE control, you gained ICE efficiency by running the ICE at a constant speed and load. This helped to make up for the conversion losses. With today's computer engine control, that's not true any more. ICEs are now much more efficient over a wider range of speeds and loads. So there are fewer situations where a series hybrid is apt to give you improved efficiency. This is where the parallel hybrid comes in. A parallel hybrid can mechanically link either the motor or the ICE to the driveline - sometimes both. This is the system you're proposing. In theory, you should get the best of both
Re: [EVDL] How crazy am I?
Ben, I'll diverge a bit from David's ideas. First, disclaimer: I bought a leaf and have no hands-on experience. One way you could have an ICE and room for EV components is to completely take out the existing ICE and replace it with something much smaller. Even though David claims the parallel configuration is more optimal, and I agree, you could do a series configuration with the electric motor heading the drive train. You then use the ICE to power the electric motor. I imagine several benefits of this: 1. smaller ICE - it only needs to be large enough to maintain constant speed up a long grade. Say you're on a 5% freeway grade and want to maintain 60mph. That determines your ICE size, considering losses for elec. generation, etc. You get acceleration from the electric motor; e.g. the leaf is 80kw and I think the volt is around 100kw; the ICE needs to be just big enough to provide elec. power for long-average loads. 2. more flexibility on how to use the space under the hood. The ICE could even be in the trunk. 3. You can run electric only and never use the ICE for short trips - depending on your battery size. Disadvantages: 1. most of the things David relates. 2. you might have issues with the engine computer since you probably would still need it for running the dash accessories, etc. Peri -- Original Message -- From: EVDL Administrator via EV ev@lists.evdl.org To: Electric Vehicle Discussion List ev@lists.evdl.org Sent: 19-Jul-14 1:16:45 PM Subject: Re: [EVDL] How crazy am I? Hi Ben, I'm a little surprised at the light response you've gotten to your question. I would have thought there'd be more folks here who at least have put some thought into homebrewing a hybrid this way, if not done it themselves. So, even though I'm about the worst person to do so since I'm a EE dropout and have never built a hybrid, I'll post a few random ideas about them that have popped into my head over the years. First, some thoughts on why or why not. ICEVs' efficiency has improved immensely from microprocessor engine control, but it's still pretty abysmal on short trips. For some folks, short trips can amount to a lot of driving - take the kids to school, come home, run to the store, come home, pick the kids up, come home ... repeat to 40 or 50 significant digits. That kind of use is also hard on an ICE, because it never gets properly warmed up. OTOH, EVs excel at short trips. They don't need to warm up, they don't idle, and many have regen to claw back some kinetic energy normally wasted as heat in the brakes.. For folks who need to make both short and long trips, intuitively the true hybrid seems like an ideal compromise. However, the devil is in that little word, compromise. It's because you have two vehicles in one. To stick with conversions here, you're in effect doing a full EV conversion, but still leaving the engine and all its supporting hardware in place. You have to find a place to mount the EV drive components and the battery; but unlike a BEV conversion, you don't have nice big chunks of space where the ICE and gas tank used to be. So you have a packaging challenge. Your vehicle also gains a fair bit of weight. And there are other little places where you miss out on efficiency. For example, with the exhaust still there, you probably can't add a belly pan to smooth out the underbody aerodynamics, as you could with a BEV. The result is that your hybrid isn't going to be optimized as either an ICEV or an EV. It's likely that its EV range will be less than a similar BEV's, and its fuel efficiency less than a similar ICEV's. So after thinking all this over, I've decided that I'm more in favor of having multiple vehicles. Each can be optimized for different needs - an EV for local trips, and an ICEV for long trips, for example. This is a great solution where you have two drivers and two cars. With just one driver, I guess it depends partly on what it costs to license and insure two vehicles in your area. I also really like the station car concept, where you commute using mass transit, and lease an EV for daily use between your house and the train station. In the best of these proposals, you can also swap your EV for an ICEV car or van or truck, when you need that instead (you want to go on vacation with the kids, or to fetch a load of lumber). Alas, I don't see many of these on the horizon. Not that I'm trying to talk you out of this project, just presenting some things to consider. Now, again, I'm not really the right person to advise you. But maybe if I cast out some ideas here, someone else will pop up and disagree with me ;-) First a little of my somewhat quirky nomenclature. I'm an old guy, so hybrid still means to me what it meant in 1969. To me, a hybrid is a vehicle that can use multiple energy sources. The cars most folks call hybrids today get all their energy from gasoline. Others here disagree
[EVDL] How crazy am I?
For quite some time, I've had vague plans of getting an electric vehicle of some sort. When I put the solar array on my roof a couple years ago, I intentionally oversized it so I'd have enough extra to charge a car and still have (roughly, of course) net zero electric use. Until recently, the thought has been to get a Karmann Ghia and do a traditional straight-ahead full electric conversion. However, I have the chance to buy a 1964 1/2 Mustang in good shape for very little money...and that's led me on a rather interesting investigation. I came across a Web site of a guy with a '66 Mustang who replaced his alternator with an electric motor, and uses it to take some of the load off the internal combustion engine and get a gas mileage boost. (No perpetual motion; the motor is battery-powered, with the batteries charged from a wall socket and regen.) I know I wouldn't at all be happy with such weak sauce for a system, so I've done a lot of research and thinking about various options, including many that I've figured out wouldn't work (bigger motor with Gilmer belt, mounting the motor to the front of the crankshaft, etc.). I'm now down to a last hope, but one that I think might actually not be unreasonable. I should take a moment and describe what I have in mind for the goal of the project: something with a driving experience not unlike the Chevy Volt. It should have an all-electric range of a couple dozen miles or so, and a total range limited only by gasoline availability. After the batteries run down enough, it should work like a traditional hybrid, with at least some regen braking and acceleration assist. And if it winds up being more than merely peppy when running with a full battery charge plus the internal combustion motor, that's fine as well. ...and this would also be a good place to mention that I'm fully aware that everything is about compromises, and the farther one strays from the beaten path, the more one must compromise. So, with that out of the way, the idea is to keep the internal combustion motor and its transmission basically unmodified, and to mount the electric motor inline between the transmission and the differential. My hope is that, if I approach this as an high-performance direct-drive all-electric system with a big enough motor and controller, the only compromises will be cost and the expected complexity of a high-performance system (cooling, power transfer, that sort of thing). That is, design it as if I were creating a direct-drive racer (though perhaps an entry-level one rather than a record-breaker) with the electric motor mounted to the (appropriately geared) differential, and then connect the ICE's transmission to the forward end of the electric motor with a shortened drive shaft. My biggest question: is this completely crazy? Am I setting myself up for an expensive white elephant? Some of the questions and compromises that I'm already aware that I'm going to have to face... Picking a motor and controller that can handle the load of direct drive: what do I actually need? I'm kinda drawn to a dual AC-35 setup; would that work, or do I need even more? Could I get away with less? Again, I don't need something that'll win races, but I'm well aware that I might need something race-worthy just to get something that won't melt and / or burn up under low-speed current loads. What kind of gearing am I going to need for the differential? Can I get something low enough with stock options, or would I need a custom differential? This would also obviously affect the gearing for the internal combustion engine...again, are there reasonable stock transmission options, or am I going to need a transmission with custom gear ratios? (The car currently has a three-speed auto, which I've long since assumed would go.) How programmable are the motor controllers? I have in mind using the internal combustion motor's vacuum pressure rather than foot pedal position to set the electric motor's power when in hybrid modes, and I'd probably want different mappings depending on battery charge -- and, of course, there wouldn't be *any* vacuum in pure electric mode. I pay my bills by doing database programming. That's a different beast from this type of embedded system, I know, but I'm not afraid to dive into a new language...assuming it's something that's possible. I live in the Valley of the Sun, so I already know cooling is going to be a problem. Worse, I have no garage, so the car is going to be outside in the heat when charging. I'm assuming chill plates will take care of the controller(s). The car doesn't currently have A/C, so I'm thinking of getting something that runs purely electrically, and making it oversized, and running a duct to the batteries and motor (in addition to the cabin). When plugged in to the wall, I could then run the car's A/C to keep the batteries happy; when driving, the A/C could provide cooling to the batteries and
Re: [EVDL] How crazy am I?
PM Subject: [EVDL] How crazy am I? For quite some time, I've had vague plans of getting an electric vehicle of some sort. When I put the solar array on my roof a couple years ago, I intentionally oversized it so I'd have enough extra to charge a car and still have (roughly, of course) net zero electric use. Until recently, the thought has been to get a Karmann Ghia and do a traditional straight-ahead full electric conversion. However, I have the chance to buy a 1964 1/2 Mustang in good shape for very little money...and that's led me on a rather interesting investigation. I came across a Web site of a guy with a '66 Mustang who replaced his alternator with an electric motor, and uses it to take some of the load off the internal combustion engine and get a gas mileage boost. (No perpetual motion; the motor is battery-powered, with the batteries charged from a wall socket and regen.) I know I wouldn't at all be happy with such weak sauce for a system, so I've done a lot of research and thinking about various options, including many that I've figured out wouldn't work (bigger motor with Gilmer belt, mounting the motor to the front of the crankshaft, etc.). I'm now down to a last hope, but one that I think might actually not be unreasonable. I should take a moment and describe what I have in mind for the goal of the project: something with a driving experience not unlike the Chevy Volt. It should have an all-electric range of a couple dozen miles or so, and a total range limited only by gasoline availability. After the batteries run down enough, it should work like a traditional hybrid, with at least some regen braking and acceleration assist. And if it winds up being more than merely peppy when running with a full battery charge plus the internal combustion motor, that's fine as well. ...and this would also be a good place to mention that I'm fully aware that everything is about compromises, and the farther one strays from the beaten path, the more one must compromise. So, with that out of the way, the idea is to keep the internal combustion motor and its transmission basically unmodified, and to mount the electric motor inline between the transmission and the differential. My hope is that, if I approach this as an high-performance direct-drive all-electric system with a big enough motor and controller, the only compromises will be cost and the expected complexity of a high-performance system (cooling, power transfer, that sort of thing). That is, design it as if I were creating a direct-drive racer (though perhaps an entry-level one rather than a record-breaker) with the electric motor mounted to the (appropriately geared) differential, and then connect the ICE's transmission to the forward end of the electric motor with a shortened drive shaft. My biggest question: is this completely crazy? Am I setting myself up for an expensive white elephant? Some of the questions and compromises that I'm already aware that I'm going to have to face... Picking a motor and controller that can handle the load of direct drive: what do I actually need? I'm kinda drawn to a dual AC-35 setup; would that work, or do I need even more? Could I get away with less? Again, I don't need something that'll win races, but I'm well aware that I might need something race-worthy just to get something that won't melt and / or burn up under low-speed current loads. What kind of gearing am I going to need for the differential? Can I get something low enough with stock options, or would I need a custom differential? This would also obviously affect the gearing for the internal combustion engine...again, are there reasonable stock transmission options, or am I going to need a transmission with custom gear ratios? (The car currently has a three-speed auto, which I've long since assumed would go.) How programmable are the motor controllers? I have in mind using the internal combustion motor's vacuum pressure rather than foot pedal position to set the electric motor's power when in hybrid modes, and I'd probably want different mappings depending on battery charge -- and, of course, there wouldn't be *any* vacuum in pure electric mode. I pay my bills by doing database programming. That's a different beast from this type of embedded system, I know, but I'm not afraid to dive into a new language...assuming it's something that's possible. I live in the Valley of the Sun, so I already know cooling is going to be a problem. Worse, I have no garage, so the car is going to be outside in the heat when charging. I'm assuming chill plates will take care of the controller(s). The car doesn't currently have A/C, so I'm thinking of getting something that runs purely electrically, and making it oversized, and running a duct to the batteries and motor (in addition to the cabin). When plugged in to the wall, I could then run the car's A/C to keep the batteries happy
Re: [EVDL] How crazy am I?
for a engine with a sweet spot in that range, the 11 inch motor has a sweet spot at 1800 rpm, so I use a torque converter that has full lock up at 1700 rpm which is close enough. The sweet spot of a prime mover is where the horse power and torque are at is maximum. Therefore the motor ampere will be at the lowest at this point. When I design my EV for motor only drive, I contacted George Hamstra at NetGain to verify the engineering of a EV using a WarP 11 motor. His email address is: host...@go-ev.com or host...@comcast.net or ghams...@g0-ev.com You send him the type of vehicle you want to use, the estimate weight without the motor and battery pack, wheel size, tire diameter, transmission gear ratios in each gear, the estimate average speed and range you want. If you want to have the vehicle as a hybrid that can work as a full EV only, than you will need the weight of the vehicle with the engine and its components. He will then send you a spread sheet with the size of motor either in straight EV or using a TransWarP motor set up, the battery pack size for a TransWarP system or for a EV only battery pack which will be size in ampere hour and voltage. The battery pack for a TransWarP system will be less ah and voltage if you only attend to use the engine/electric all the time. If you want to have the engine either idle down or shut down, than the battery pack will have to be size as for a EV only. The spreadsheet will give you a estimated speed, rpm, motor amp, battery amp, battery voltage, and range of the vehicle. The TransWarp motor is normally use with its own controller which interfaces with a computer in the vehicles with a computer control transmission which detects the engine load and thus shifts the transmission at the ideal rpm and load. If your vehicle does not have a computer control transmission, you than could use engine vacuum load sensors like I did back in the 80's. Roland - Original Message - From: Ben Goren via EV To: ev@lists.evdl.org Sent: Thursday, July 17, 2014 9:58 PM Subject: [EVDL] How crazy am I? For quite some time, I've had vague plans of getting an electric vehicle of some sort. When I put the solar array on my roof a couple years ago, I intentionally oversized it so I'd have enough extra to charge a car and still have (roughly, of course) net zero electric use. Until recently, the thought has been to get a Karmann Ghia and do a traditional straight-ahead full electric conversion. However, I have the chance to buy a 1964 1/2 Mustang in good shape for very little money...and that's led me on a rather interesting investigation. I came across a Web site of a guy with a '66 Mustang who replaced his alternator with an electric motor, and uses it to take some of the load off the internal combustion engine and get a gas mileage boost. (No perpetual motion; the motor is battery-powered, with the batteries charged from a wall socket and regen.) I know I wouldn't at all be happy with such weak sauce for a system, so I've done a lot of research and thinking about various options, including many that I've figured out wouldn't work (bigger motor with Gilmer belt, mounting the motor to the front of the crankshaft, etc.). I'm now down to a last hope, but one that I think might actually not be unreasonable. I should take a moment and describe what I have in mind for the goal of the project: something with a driving experience not unlike the Chevy Volt. It should have an all-electric range of a couple dozen miles or so, and a total range limited only by gasoline availability. After the batteries run down enough, it should work like a traditional hybrid, with at least some regen braking and acceleration assist. And if it winds up being more than merely peppy when running with a full battery charge plus the internal combustion motor, that's fine as well. ...and this would also be a good place to mention that I'm fully aware that everything is about compromises, and the farther one strays from the beaten path, the more one must compromise. So, with that out of the way, the idea is to keep the internal combustion motor and its transmission basically unmodified, and to mount the electric motor inline between the transmission and the differential. My hope is that, if I approach this as an high-performance direct-drive all-electric system with a big enough motor and controller, the only compromises will be cost and the expected complexity of a high-performance system (cooling, power transfer, that sort of thing). That is, design it as if I were creating a direct-drive racer (though perhaps an entry-level one rather than a record-breaker) with the electric motor mounted to the (appropriately geared) differential, and then connect the ICE's transmission to the forward end of the electric motor with a shortened drive shaft. My
