Re: [EVDL] Lawn tractor conversion: lessons learned
New lesson learned this weekend. On Mon, Jul 28, 2014 at 10:59 PM, Michael K Johnson mcda...@gmail.com wrote: Talking myself into doubling my 4awg welding cable for the equivalent cross sectional area of 1awg was almost certainly overkill. Joe Lorenzi has 8awg in his JD with the same motor, and he told me that it gets a little warm and thicker than 8awg would be useful, but I really don't think I need 1awg equivalent. Even immediately after mowing through thick grass with no breaks for nearly half an hour (down to 50%DoD) my cables are cold. If I were doing it over, I would just use the 4awg cable. Would be easier and use lighter, easier-to-manage lugs, and routing would be less of a challenge than it was. I changed my mind this weekend. To prepare for aeration and overseeding, I mowed my lawn short. I normally mow with the deck raised to maximum height (good for fescue lawns), but to prepare to aerate and overseed, I nearly scalped the lawn. I still mulched while doing this to create cover for the seeds when overseeding. Cutting the grass low takes far more power; so much so that a few times the cutting blades nearly stalled. Normally I can mow front and back without exceeding 50% DoD while mowing up to 26 minutes. Cutting just the front, taking well under 20 minutes (going slowly), I significantly exceeded 50% DoD. Don't know exactly how much because I couldn't let the battery rest to get a precise measurement; I had to charge right away to keep going in order to finish the project this weekend. What clued me in to bring the mower back in to charge very early was that the 2 4awg cables (1awg cross sectional equivalent) were quite warm to the touch. Not too hot to touch, but perhaps 50⁰C. I don't know how much current I was drawing, but in any case I now feel that 1awg equivalent was a good choice, and if I ever get stiffer batteries, I'll want to consider even larger wires. Roland, thanks for recommending that I double the wires! I bought both 400A and 200A fuses, not sure whether it would blow the 200A fuse. I needn't have worried. I do see over 100A continuous, but the 200A fuse hasn't blown. The batteries just can't push that much current through that motor... Even while bogged down, with the blades occasionally almost stallling when the deck started getting clogged, and the wires getting warm, the 200A fuse did not blow. ___ 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] Protecting DC PWM Controller from low inductance/resistancemotors
On Mon, Aug 11, 2014 at 11:24 PM, Lee Hart leeah...@earthlink.net wrote: Yes, you need to remove the magnetic shunts. These are rectangular blocks of laminations tack-welded into the space between the primary and secondary. This restores the core to a normal E-I laminated stack. I wasn't referring to the shunts. If you remove both the primary and secondary in order to use the core to make an inductor, it would be hard to leave the shunts in place, at least in my experience... I meant the center bar of the E, leaving a C shape. Since the wire will be carrying 100s of amps, it needs to be very thick. It's hard to wind such thick wire. A better alternative is to use many smaller strands in parallel. Or, use a long strip of sheet copper flashing. Put a paper cuff around it, or tape or other insulation. The voltage per turn is low, so not much insulation is needed between turns. For my spot welder, I found it difficult enough to wind three turns of two parallel 8awg wires into the secondary space that I had cut out of a 1500W GE microwave oven transformer. That was before I found myself with leftover 4awg welding cable from my tractor conversion, so if I use that spot welder any more I'll probably change to the welding wire to be able to carry more current and not get as hot. ☺ ___ 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] Protecting DC PWM Controller from low inductance/resistancemotors
Cor, How many turns did you wind? I'm assuming you removed the center portion of the EI in order to get a rectangular shape? Adam, Check http://www.geepglobal.com/locations/usa/north-carolina/ if you don't find anything high-power on craigslist. I suppose if you need more room for wire you could get two and discard the I sections as well as the center bars of the E sections and hold them together with the openings facing each other... On Mon, Aug 11, 2014 at 5:51 PM, Cor van de Water via EV ev@lists.evdl.org wrote: Adam, I added a (free) inductor by wrapping the motor wires around the core of the biggest microwave transformer that I could find. You can pick up old microwaves most days from Craigslist and the like for free. I occasionally get one, disassemble it if I can't get it to work to give to a needy friend, so I have a stash of components to fix the next one. Note that it is required to put a very thin spacer between the two core halves to avoid saturation and you need something (I used a very large hose clamp plus 1 or 2 steel wires cross-wise along the core) to keep the two halves together and aligned. 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 Adam Chasen via EV Sent: Monday, August 11, 2014 2:16 PM To: ev@lists.evdl.org Subject: [EVDL] Protecting DC PWM Controller from low inductance/resistancemotors I recently purchased a 1980 Lectric Leopard (Renault 5 Le Car http://www.evalbum.com/190) with the following specifications: * original Presolite 6.7(?) series wound DC motor (presumably advanced for higher voltages) * 16kWh LiPo NMC packs in 24s4p arrangement for 90V nominal with 150A semiconductor on each of the 4 packs * Curtis 1231C controller with PB-6 2 weeks ago I heard a loud pop as I depressed the throttle out of a rolling stop/turn and my voltmeter read 0. Seemed like my semiconductor fuses did the job and all 4 were popped ($100 worth of fuses mind you). Unfortunately in my distressed mindset I bypassed the fuse on one pack and the car lurched a few inches as soon as I flipped my breaker and then stopped (I know, bad call). I disassembled the Curtis controller and discovered 2 gently blown mosfets and 1 catastrophic mosfet failure. I ordered replacement mosfets IXTH50N20. One trace on the power board looks like it overheated and there appears to be some damage (a resistor?) on the control board. There is possibly damage to a trace in an internal layer, but not sure if it is a 2 layer board and some surface heating caused some damage. I have since swapped the Curtis out for a 750A Logisystems which I am aware are plagued with (similar?) issues. These failures appear to be due to low resistance/low inductance motors causing a overcurrent condition. The logisystems doesn't provide for a 1.5kHz during startup. That is a bit concerning as that was the workaround for the Curtis. I have since measured the motor side of the controller with an inrush current sensor and measured 645A max even with being very careful to slowly depress the throttle. My concern centers around this happening again, especially on my larger 1989 BWM 535i with a directly coupled FB1-4001a motor. There are a few proposed solutions I read about and a few I came up with on my own which I am soliciting opinions on. A big unknown to me is how much resistance or inductance needs to be introduced to prevent this kind of inrush/runaway. One solution is to use the clutch in the Leopard to ensure there is no starting load on the motor. I still measured inrushes of 300A with no load! That will not work for my directly coupled 1989 BMW. I am curious if Lee Hart (with his Leopard) and others with series wound DC motors drive using the clutch. I have since modified my shifting behavior to much higher RPMs after reading some about his driving style. Another is to control the current with a large inductor. There was a lot of talk, but no pictures of these inductors. I am not sure how much inductance is necessary to help, but haven't done much research into this. There was some mention of using surplus transformers with insulated layers, but wasn't able to get a good picture in my head of size and process. Someone mentioned a 30 lbs choke on an older PMC, but that also doesn't provide me a good picture in my head other than it will likely be bigger than any non-power system transformer I have ever seen. Where can I get one (or the materials for) of these inductors and how much will the cost? There are two other passive electronic components which can control current I didn't see mentioned. * Resistors * Thermistor I am not sure about the practicality of using a thermistor for this purpose.
Re: [EVDL] EVDL biz: H2 and FCEV discussion
Speaking as a newbie to the list (last November), I've been surprised by the levels of invective levelled at H2. There have been a lot of assumptions that it cannot possibly ever be efficiently produced without a bad carbon footprint, and lots (my perception) of ad hominem attacks. I'd like to think that if we can find ways to efficiently and cleanly produce new battery technologies, we could have our minds open to the possibility of clean H2 generation, separating the issue that in practice right now most H2 generation is very dirty from the question of different forms of chemically storing electrical energy in the long run. Change to allow H2 discussion, or continue to ban it, but the derogatory language about it gets tiresome and I'll bet it turns off more people than just me. When looking for problems to police, if you want to police H2 discussions, I would suggest to include in the policing derogatory comments about the technology and people as well as promotion and technical discussion thereof. Complaining only about the promotion and letting the derogatory comments slide is kind of a one-sided enforcement of the rules. My 2¢, do what you like, I'm hardly a major contributor here. ☺ On Tue, Jul 29, 2014 at 1:30 PM, EVDL Administrator via EV ev@lists.evdl.org wrote: The original EVDL charter, written by our founder Clyde Visser back in the internet's dim past (1991) says, the energy storage device [for an EV] ... can [be a] ... fuel cell ... But not too far into this long history of the EVDL - I think about 1995 or so - we had a pretty detailed discussion about discussion of FCEVs and H2. We even took a vote, and folks decided that we'd minimize FCEV and H2 discussion. Was that a mistake? Is it a mistake to continue on that road? The folks who say that H2 is the way forward surely think so. Well, if it is, we're still making it today. (Hint, hint.) You know, one of the huge advantages of the internet is that, unlike broadcast spectrum, it's effectively just about infinite. Unlike newspapers and magazines, it's dirt-cheap to make your voice heard, at least so far. There's room for lots more internet discussion forums like this one. Somewhere there has to be a place where H2 and FCEV enthusiasts can congregate. If not, it's almost trivial to start one. Thus I will refer y'all to the EVDL conventions: http://www.evdl.org/help/index.html#conv Please read point 2f. Thanks, 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] Lawn tractor conversion: lessons learned
On Tue, Jul 29, 2014 at 1:30 PM, Lee Hart leeah...@earthlink.net wrote: Michael K Johnson via EV wrote: I'd seriously consider getting together with friends on a scavenged Volt battery... That could be fun as an experiment, but could cost more and require more finesse to get it all to work. Dumb old lead-acids are easier, and a reasonable first-EV solution. Well, a few months after I bought my batteries, a friend bought a few scavenged volt batteries, and it literally would have cost me less than the $1K I paid for the SLAs to have more capacity with greater available discharge. So I'm not being crazy here. I would have needed a different charger for lithium, though. That's where the money would have gone. Putting the motor in a pressurized box is an interesting solution. The foam filters apparently have a low enough pressure drop to work with propeller-type fans. The more common approach uses a squirrel-cage blower with a higher-drop filter element. The plenum exhaust area is about 2x12 and the frame around it stays clean; it's clearly moving a lot of air. I do brush off the filter after each mowing session because it collects detritus around the intakes. I sized the frame just small enough for a good interference fit. Is it real plexiglass (brittle acrylic), or the more common polycarbonate (slightly flexible, nearly unbreakable)? Polycarbonate is so strong that even 1/8 would be indestructible. Acrylic. Polycarbonate is more expensive and really hard to work, as your point about the indestructibility of 1/8 stock attests to. If I had gone with 1/4 acrylic for the whole box, I could have used simple butt joints and screwed the pieces together and it would have been far less work. I did find out a couple weeks too late that I could have brought the acrylic to a friend and co-worker who would have cut it for me with his laser cutter. Maybe next winter... ☺ Well, it's a small matter. Your wire lengths are short, so not a lot of loss no matter how you do it. What ulitmately matters is that the wire doesn't get hot, and you've certainly achieved that. It's a small amount of extra money in the grand scheme of the conversion, and I don't really regret it. I'm merely recording for the next person that my impression was that it was overkill for the tractor. I don't think these batteries can source enough current to overheat 4awg; they start noticeably sagging around 140A-150A. Might be different with lithium. Buying SB50 anderson connectors for charging at 48V 6A max was silly; But, they are very robust and will last. They can carry 6a even when dirty, worn, and corroded. Maybe you'll get a higher current charger someday. (Your AGMs might like higher-current charging anyway). I cut the female end off a C15-C15 extension, and used the male C15 end of the cord for my charging circuit. I used liquid electrical tape (many layers) to cover the conductors coming out of the cut-off end of the cord, and keep the male end plugged into that cut-off plug to keep the male connector clean when I am not charging the traction batteries. But if I ever make one of the open source chargers that can dump more than 6A into the batteries, I'll keep the SB50s in mind, of course. $1200-1400 for the EMW kit is more than I want to spend on that right now. I'm still recovering from blowing the budget in the first place. 48v input to 12v output DC/DC converters are pretty common; the Telco industry used them in quantity. You can probably find one surplus for $10-$20 that can run fans, contactor coils, and your amphour meter. As it turns out, the old 12V battery is toast. But I have some SLA batteries that UPS units were complaining about but which have lots of life left in them and I'll use them for house. Even cheaper than buying an isolated converter. Of course I don't have a 12V charger handy, so I cobbled together the power supply from a dead laptop, a buck converter with a CV regulator, some wires scavenged from a dying coffee mater, and my meter to make sure I'm within spec, and voila, a charger! Someone else could use a converter to run fans and contactor coils, but since I have 48V fans and contactor coils, I'd have to replace them to switch, and that doesn't seem worthwhile. The 48V fans came out of telco gear where 48V is, as you point out, common. If that's a worry, 48v contactor coils are very common. That's what I have. I just seem to recall that the 48V contactor coils drew more current than the 12V in the same series (Alltrax). On snowmobiles and other users of this variable-pulley-size method, they sometimes use metal belts (chains) with little friction pads on the sides. They are more efficient than the typical rubber v-belts. Maybe one is available for the size needed here? I doubt it. This is a long belt and needs to flex and runs through frankly poorly-guided space. I'll stick with OEM and would suggest the same for anyone trying to convert similar tractors
[EVDL] Lawn tractor conversion: lessons learned
I got lots of useful help here on my lawn tractor conversion project — http://www.evalbum.com/4841 — so I thought I'd post some lessons learned, both positive and negative. None of this is intended as advice for anyone else, for obvious reasons. I'm not doing everything as safely as I might! This is just the brain dump I wish someone else had written for me to read when I was getting started. Biting the bullet and buying real batteries (Deka Intimidator 9A31) was a good idea. Mowing my half-acre lot that's not much more than half lawn sometimes brings me close to 50% DoD, occasionally perhaps very slightly below. It took a bit of convincing myself to spend $1K on batteries—almost twice what I spent on the Motenergy ME1004 motor. Part of what got in the way of accepting that reality early on was a silly idea that I could fit everything under the existing hood and it would look the same, just be quieter. Things got a lot easier when I decided to ditch the hood and embrace as part of the conversion the fact that this was going to look way different when I was done. If I were starting over today, I'd seriously consider getting together with friends on breaking a scavenged Volt battery and doing a 2p15s or 3p15s arrangement (I don't recall the capacity of the volt cells). Scavenged Volt batteries seem to be going for around $2K so if enough people wanted to get together on it, this would have been an opportunity to get more capacity for less money. I hope that by the time my current batteries are going downhill, lithium cells are a dime a dozen. Installing muffin fans pulling cooling air through a reticulated foam filter (like they use for aquariums) to provide positive pressure cleaned air in a plenum around the motor was a good idea. The motor stays clean. I don't know if it matters for cooling, since I'm running the motor well under rated load. But cleaned air can't hurt brush life. I count that as worth the 1.2A continuous draw. Using plexiglass to make that plenum was a great idea. Using 1/8 plexiglas for the sides and 1/4 only for the top where the muffin fans were mounted was a false economy; if I were doing it again I would make the whole plenum out of the more expensive, but more robust and easier to work 1/4 plexiglass. Given the frame I had to build to support the 1/8 plexiglass, I think that it would have taken me less than half the time if I'd done it all in 1/4 plexiglass. However, using a sectional picture frame (the kind where you purchase two packages to make one frame, one package for each dimension) as the holder for the reticulated foam worked quite well. I'd do the same thing again even if I weren't so incredibly lucky as to find the frame packages on sale for 95% off... I used a combination of glue and brass screws to hold the plexiglass together; if I were doing it again I'd just use the brass screws. They look pretty cool in the plexiglass box if I do say so myself. Talking myself into doubling my 4awg welding cable for the equivalent cross sectional area of 1awg was almost certainly overkill. Joe Lorenzi has 8awg in his JD with the same motor, and he told me that it gets a little warm and thicker than 8awg would be useful, but I really don't think I need 1awg equivalent. Even immediately after mowing through thick grass with no breaks for nearly half an hour (down to 50%DoD) my cables are cold. If I were doing it over, I would just use the 4awg cable. Would be easier and use lighter, easier-to-manage lugs, and routing would be less of a challenge than it was. I bought both 400A and 200A fuses, not sure whether it would blow the 200A fuse. I needn't have worried. I do see over 100A continuous, but the 200A fuse hasn't blown. The batteries just can't push that much current through that motor... Hooking up my power switch so that the charging cable is connected in one direction, and the contactor in the other, means that I can't accidentally try to charge it and run it at the same time, and makes it less likely that I'll drive away and leave the charger connected. Buying SB50 anderson connectors for charging at 48V 6A max was silly; the charger came with C15 (just like in the back of your computer) which works fine. So I have some unused SB50 anderson connectors... I was originally going to connect both sides of the motor through an SB350 anderson connector for a disconnect. Instead, I put a single pole PP disconnect (using exactly the same internals as the SB350) inline next to the fuse as my emergency disconnect / safety maintenance disconnect. Requires only half the effort to pull it open in an emergency, and the loop of wire that doubles as the emergency disconnect handle is also convenient for my clamp ammeter! So I also have some unused SB350 anderson connectors... I wanted to avoid a 12V house battery and run everything off of 48V due to my initial expectation to install one of my batteries under the seat, before I settled on the 9A31 batteries that couldn't possibly fit.
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] Miles Remaining
Found an ebay listing for WRB4812S which has 36-72V input and 12V output. Bought it. Then re-read and found that it's a 1W part and the meter is listed at 2W. Oops. Guess I'll measure what it actually draws; I assume that's for the relays that I don't even want to drive. Maybe I can configure the setpoints so that it doesn't draw power for the relays and it lives on 1W... On Thu, May 15, 2014 at 8:59 PM, Michael K Johnson mcda...@gmail.com wrote: Well, my system floats from the frame, but lightobject responded: : The power of the JLD404 is isolated and the ground of the : power negative has no common to the Input ground. You do : NOT want to common ground the power and the INPUT ground. : Otherwise, the amp meter won't work and that is the pretty of the : JLD404 with isolated Ground So I guess it's off to ebay for an isolating power supply. I haven't seen one yet that can handle 48V and output 12V, so it looks like I'll have to put it downstream from my buck converter. On Thu, May 15, 2014 at 1:34 PM, Rick Beebe r...@beebe.org wrote: Jack's concern was that the meter might make a connection between frame ground and the high voltage pack so he put the DC-DC in for isolation. I did have that problem on the analog volt meter I used to have in the truck so I put one in as well. However I don't have any evidence to suggest it's really necessary for this meter. I haven't found any continuity between the 12v power and high voltage connections on the meter. But the DC-DC was only a couple bucks so it was cheap insurance. --Rick On 05/14/2014 08:17 PM, Michael K Johnson wrote: Thank you! That's perfect! All you are really doing is programming mV/A with a max of 75mV, so that makes sense. The EVTV diagram says Isolated 12v to 12v DC-DC Converter. I didn't see anywhere else that the negative power terminal on the JLD404AH cannot be tied to the COM terminal. And all my 12V regulated supplies are common negative. I don't have a separate 12V house battery in the lawn tractor. Are you using an isolated dc-dc converter in your truck? On Wed, May 14, 2014 at 9:10 AM, Rick Beebe via EV ev@lists.evdl.org wrote: I have one in my truck and it works great. It wants a 75mV shunt but I have a 50mV/500A. You just lie the meter--I.e. I said it was connected to a 75mV/750A shunt. The manual is available here: http://www.lightobject.info/viewtopic.php?f=14t=1074 Jack Rickard of EVTV has written a plain english one here: http://media3.evtv.me/JLD404AH.pdf. --Rick ___ 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] Miles Remaining
Well, my system floats from the frame, but lightobject responded: : The power of the JLD404 is isolated and the ground of the : power negative has no common to the Input ground. You do : NOT want to common ground the power and the INPUT ground. : Otherwise, the amp meter won't work and that is the pretty of the : JLD404 with isolated Ground So I guess it's off to ebay for an isolating power supply. I haven't seen one yet that can handle 48V and output 12V, so it looks like I'll have to put it downstream from my buck converter. On Thu, May 15, 2014 at 1:34 PM, Rick Beebe r...@beebe.org wrote: Jack's concern was that the meter might make a connection between frame ground and the high voltage pack so he put the DC-DC in for isolation. I did have that problem on the analog volt meter I used to have in the truck so I put one in as well. However I don't have any evidence to suggest it's really necessary for this meter. I haven't found any continuity between the 12v power and high voltage connections on the meter. But the DC-DC was only a couple bucks so it was cheap insurance. --Rick On 05/14/2014 08:17 PM, Michael K Johnson wrote: Thank you! That's perfect! All you are really doing is programming mV/A with a max of 75mV, so that makes sense. The EVTV diagram says Isolated 12v to 12v DC-DC Converter. I didn't see anywhere else that the negative power terminal on the JLD404AH cannot be tied to the COM terminal. And all my 12V regulated supplies are common negative. I don't have a separate 12V house battery in the lawn tractor. Are you using an isolated dc-dc converter in your truck? On Wed, May 14, 2014 at 9:10 AM, Rick Beebe via EV ev@lists.evdl.org wrote: I have one in my truck and it works great. It wants a 75mV shunt but I have a 50mV/500A. You just lie the meter--I.e. I said it was connected to a 75mV/750A shunt. The manual is available here: http://www.lightobject.info/viewtopic.php?f=14t=1074 Jack Rickard of EVTV has written a plain english one here: http://media3.evtv.me/JLD404AH.pdf. --Rick ___ 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] Miles Remaining
That AH meter at lightobject looks very interesting. It doesn't say what shunt or range of shunts it can use that I can see. I have a buck converter that I can put on my tractor to power the meter, but obviously I'd need to use a shunt to measure current. I have a 50mV/500A shunt installed; do you have docs to check whether it would work? On Wed, May 14, 2014 at 12:21 AM, John Lussmyer via EV ev@lists.evdl.org wrote: On Tue May 13 21:11:33 PDT 2014 ev@lists.evdl.org said: Thanks, Denis. It looks like a pretty simple display. I'm sorta hoping for something with more numbers on it. There seem to be a number of units on eBay that only go to 100 V and 30 A: http://www.ebay.ca/itm/5-in-1-Digital-Combo-Panel-Meter-DC100V30A-Volt-Amp-kWh-Watt-Working-Time-/181403417248?pt=LH_DefaultDomain_2hash=item2a3c7c7aa0_uhb=1 but I'm hoping for something more like this that will do 196V and up to 500 A: http://www.accuenergy.com/?discography=acudc-240-series This unit could display volts, amps, and kWH simultaneously, but I haven't found a supplier nor even a price! I'm going to try one of these: http://www.lightobject.com/Programmable-Digital-AH-meter-Ideal-for-battery-monitoring-P278.aspx I have it on my desk, but haven't hooked it up to anything yet. -- 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) ___ 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] Miles Remaining
Thank you! That's perfect! All you are really doing is programming mV/A with a max of 75mV, so that makes sense. The EVTV diagram says Isolated 12v to 12v DC-DC Converter. I didn't see anywhere else that the negative power terminal on the JLD404AH cannot be tied to the COM terminal. And all my 12V regulated supplies are common negative. I don't have a separate 12V house battery in the lawn tractor. Are you using an isolated dc-dc converter in your truck? On Wed, May 14, 2014 at 9:10 AM, Rick Beebe via EV ev@lists.evdl.org wrote: I have one in my truck and it works great. It wants a 75mV shunt but I have a 50mV/500A. You just lie the meter--I.e. I said it was connected to a 75mV/750A shunt. The manual is available here: http://www.lightobject.info/viewtopic.php?f=14t=1074 Jack Rickard of EVTV has written a plain english one here: http://media3.evtv.me/JLD404AH.pdf. --Rick On 05/14/2014 06:35 AM, Michael K Johnson via EV wrote: That AH meter at lightobject looks very interesting. It doesn't say what shunt or range of shunts it can use that I can see. I have a buck converter that I can put on my tractor to power the meter, but obviously I'd need to use a shunt to measure current. I have a 50mV/500A shunt installed; do you have docs to check whether it would work? On Wed, May 14, 2014 at 12:21 AM, John Lussmyer via EV ev@lists.evdl.org wrote: I'm going to try one of these: http://www.lightobject.com/Programmable-Digital-AH-meter-Ideal-for-battery-monitoring-P278.aspx I have it on my desk, but haven't hooked it up to anything yet. ___ 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] EV Digest, Vol 19, Issue 19
I don't use manganin battery leads (no one does), but I like a temperature-stable reference, and 10-15mV drop in normal operation is noise. ☺ And my longest battery lead is in the middle of my pack so it's biased by half the pack, which would mean that it would be more of a pain to measure since they wouldn't be common. Finally, my battery leads are 2x4ga (equivalent to 1ga) so they don't drop much. In any case, I already installed a shunt in the original build because I knew I wanted one. I just haven't bought a meter yet. I had been thinking of op amps and beaglebone black, but so far the only thing I've connected to the shunt has been my good voltmeter (which has enough accuracy and precision for the measurement to be meaningful). On Wed, May 14, 2014 at 2:11 PM, Jan Steinman via EV ev@lists.evdl.org wrote: From: Michael K Johnson via EV ev@lists.evdl.org That AH meter at lightobject looks very interesting. It doesn't say what shunt or range of shunts it can use that I can see. I have a buck converter that I can put on my tractor to power the meter, but obviously I'd need to use a shunt to measure current. I have a 50mV/500A shunt installed; do you have docs to check whether it would work? My favourite shunt is the longest battery lead. :-) Why drop any more voltage than you already are dropping? But you need a system that can be calibrated. If your longest lead drops at least 50 mV, you can put a trimpot across it to bring it down to exactly 50 mV. I've done this on two different house battery systems for campers, and it worked well. I put an amp clamp meter on the cable, together with a constant load (turning all the lights on in the camper works well), then trimming the pot until the readings were the same. Jan On Wed, May 14, 2014 at 12:21 AM, John Lussmyer via EV ev@lists.evdl.org wrote: On Tue May 13 21:11:33 PDT 2014 ev@lists.evdl.org said: Thanks, Denis. It looks like a pretty simple display. I'm sorta hoping for something with more numbers on it. There seem to be a number of units on eBay that only go to 100 V and 30 A: http://www.ebay.ca/itm/5-in-1-Digital-Combo-Panel-Meter-DC100V30A-Volt-Amp-kWh-Watt-Working-Time-/181403417248?pt=LH_DefaultDomain_2hash=item2a3c7c7aa0_uhb=1 but I'm hoping for something more like this that will do 196V and up to 500 A: http://www.accuenergy.com/?discography=acudc-240-series This unit could display volts, amps, and kWH simultaneously, but I haven't found a supplier nor even a price! I'm going to try one of these: http://www.lightobject.com/Programmable-Digital-AH-meter-Ideal-for-battery-monitoring-P278.aspx I have it on my desk, but haven't hooked it up to anything yet. -- 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) It is only the great men who are truly obscene. If they had notdared to be obscene, they could never have dared to be great. -- Havelock Ellis Jan Steinman, EcoReality Co-op ___ 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)
