Re: [EVDL] Charging my Volt from 100' of zip cord
To do stuff like this, one must also be sure the wire is fully unreeled so that it can dissipate heat. Excess heat will ruin your day. Wire that is still on a reel, or otherwise coiled up or in contact with another section of warm wire, must be heavily derated. Or more specifically, the insulation must be able to handle the heat buildup. After all, the insulation's temperature limits determine the maximum heat that can be handled (up to the point that the wire itself melts), and the resistance of the wire will lead to I^2R watts lost as heat. (And you can divide that by the wire length to get watts per foot.) Bob, have you ever charged an EV via a SWER connection? On Sun, Jul 25, 2021, 12:52 Robert Bruninga via EV wrote: > TIP: Never be caught without wire! > > You can charge a Volt (8 amps default) via 100' of simple #18 > lamp zip cord if you wanted to. (and had the 3rd GND wire). > The 5v line drop is within the standard for acceptable voltage drop. > > I routinely carry hundreds of feet of #18 zip cord for backup > and emergency power in all my vehicles because I can carry > four times as much wire under the seat in the same volume > as the standard stiff double insulated orange extension cords. > > See my spool: http://aprs.org/prius/photos/220cord3x.JPG > Ignore the 220V label, this image was for when I remotely power > things (universal power supplies) from the 220V prius battery. > > When I find such a spool, I pull off the 15' or 20' of stiff plastic orange > cord and re-wind it with 100' to 120' of #18 lamp zip cord. Note: to get > 120',you have to be very careful and obsessive in acting like a fishing > reel and laying in the zip cord flat and adjacent (no twists). But you > can do it. [But for dual wire use only - No GND wire] > > I showed up once at a downed tree and was able to plug in TWO > of these 100' cords of #18 zip cord in series to run a small > chain saw and save the day. Yes, there was noticible voltage drop > but still plenty of power to run the saw. I have even run an electric > lawnmower through one when it was more convenient than digging > out all the old orange and green cords "from around back". > > Oh, also I was able to use two of these at a rest stop for a small > space heater (on low-power (700W) and sleep in the car overnight > (well, several hours anyway) because the black zip cord just kind-of > disappeared in the joint to cross the sidewalk and then along the > edge of the sidewalk around to the back of the building where the > vending machines were plugged in. > > I would never have gotten away with that using 200' of bright > thick orange extension cords. > > Anyway, just some tall tales from the armchair > (never be caught without wire!) > Bob, WB4APR > -- next part -- > An HTML attachment was scrubbed... > URL: < > http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20210725/b264f612/attachment.html > > > ___ > Address messages to ev@lists.evdl.org > No other addresses in TO and CC fields > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > ARCHIVE: http://www.evdl.org/archive/ > LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org > -- next part -- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20210725/b697ac8b/attachment.html> ___ Address messages to ev@lists.evdl.org No other addresses in TO and CC fields UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/ LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org
Re: [EVDL] LiFePO4 EOL behavior
Some of you know this, and the info is not current, but is good for LiFePO. Anyhow, just to be complete in the discussion: When a cell is discharged, the lithium ions are on the anode and the cathode is depleted of ions. This is a pretty benign state chemically. But as the cathode loads up Li ions from charging the anode becomes very reactive. So reactive that it starts to tear up the electrolyte. Heat just makes it worse. With advancements in additives to help the electrolyte stay healthy Li cells became steadily more durable. Older CALB and other brands cells are liable to be deficient after many years. Buyer beware. Maya WoulfeiFEPO and circa 2015 On Sun, Jul 25, 2021 at 12:20 AM Michael Ross wrote: > For LiFePO, a parasitic load might be protective. It's that full charge > that is destructive. > > On Sat, Jul 24, 2021 at 11:40 PM EVDL Administrator via EV < > ev@lists.evdl.org> wrote: > >> On 24 Jul 2021 at 21:04, Michael Ross via EV wrote: >> >> > The worst thing you can do to LiFPO is to charge it fully, and let it >> sit >> > around, especially in a hot location. >> >> Isn't that the case for lithium batteries of any chemistry? I'm not a >> lithium expert by any means; I'm just asking. >> >> It occurs to me that some of Chris's parasitic loads could be coming from >> "inside the house," so to speak. That is, they might be from the BMS. >> >> I have 24v and 36v 10ah LiFePO4 batteries with a BMS with logic that's >> powered by a 12v tap (not the optimum design), and the 4 cells that power >> the BMS always take longer than the others to reach full charge. For >> long >> term storage I have read a suggestion to disconnect the BMS if possible - >> but don't forget to reconnect it when taking the battery out of storage. >> >> David Roden, EVDL moderator & general lackey >> >> To reach me, don't reply to this message; I won't get it. Use my >> offlist address here : http://evdl.org/help/index.html#supt >> >> = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = >> First they came for the journalists. We don't know what >> happened after that. >> >> -- Unknown >> = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = >> >> ___ >> Address messages to ev@lists.evdl.org >> No other addresses in TO and CC fields >> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub >> ARCHIVE: http://www.evdl.org/archive/ >> LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org >> > > > -- > Michael E. Ross > (919) 585-6737 Land > (919) 901-2805 Cell and Text > (919) 576-0824 <https://www.google.com/voice/b/0?pli=1#phones> Tablet, > Google Phone and Text > > > > -- Michael E. Ross (919) 585-6737 Land (919) 901-2805 Cell and Text (919) 576-0824 <https://www.google.com/voice/b/0?pli=1#phones> Tablet, Google Phone and Text -- next part -- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20210725/70898883/attachment.html> ___ Address messages to ev@lists.evdl.org No other addresses in TO and CC fields UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/ LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org
Re: [EVDL] LiFePO4 EOL behavior
I have a 9 year old pack of CALB blue 100Ah cells. I am seeing cells with very high self discharge. Probably 10's of milliamps. I am concerned that these high resistance shorts will become low resistance shorts and burn my garage down. (There is no excessive BMS loading) Al On 7/24/2021 9:01 AM, Christopher Darilek via EV wrote: Hi Guys, I have an 8 year old LiFePO4 pack in my car and wonder if anyone knows what the end of life failure mode is for these? Over the pandemic lock down I was not driving the car for 3 months and noticed one day that all the cells were flat, ~2V. I attributed this to some parasitic loads over the 3mo, and charged it back up. Then, with a full charge I drove ~10 miles (about 25% of my 'old' range) and parked, and after a couple weeks noticed I was back ~2V per cell. I put it on charge and it seems to have charged up and is holding voltage now. Is this how LiFePO4 batteries toss in the towel or do I still have a parasitic load to debug? What is the failure mode? Thanks for any tips. Chris http://www.evalbum.com/4743 ___ Address messages to ev@lists.evdl.org No other addresses in TO and CC fields UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/ LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org ___ Address messages to ev@lists.evdl.org No other addresses in TO and CC fields UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/ LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org
Re: [EVDL] LiFePO4 EOL behavior
For the 8 years I've had this pack my practice has been to charge it at a C/15 rate and stop when the first cell hits 3.45V. Its a 18kWh CALB. You could watch the cells go from ~3.32V to 3.45V pretty quickly, once they left 3.32V they'd be at 3.45V in <2mins and the charge stops. It's been hot, central Texas. I just got back from a range test and it's at 20 miles now. When the pack was new I claimed it had a 50 mile range, but I never went more than about 40 miles. I somewhat eliminated the parasitic load issue (reducing range?) by not letting it sit long after charge. But I plan to borrow a meter from work to check it. I'm going to cycle it a few more times, to see if capacity recovers after the lockdown sitting period, I think someone suggested that. 26236 miles total -Chris ps. I must confess, my EV grin is wider driving our Chevy Bolt, even if it does plan to catch fire someday.. On Saturday, July 24, 2021, 11:21:27 PM CDT, Michael Ross via EV wrote: For LiFePO, a parasitic load might be protective. It's that full charge that is destructive. On Sat, Jul 24, 2021 at 11:40 PM EVDL Administrator via EV < ev@lists.evdl.org> wrote: > On 24 Jul 2021 at 21:04, Michael Ross via EV wrote: > > > The worst thing you can do to LiFPO is to charge it fully, and let it sit > > around, especially in a hot location. > > Isn't that the case for lithium batteries of any chemistry? I'm not a > lithium expert by any means; I'm just asking. > > It occurs to me that some of Chris's parasitic loads could be coming from > "inside the house," so to speak. That is, they might be from the BMS. > > I have 24v and 36v 10ah LiFePO4 batteries with a BMS with logic that's > powered by a 12v tap (not the optimum design), and the 4 cells that power > the BMS always take longer than the others to reach full charge. For long > term storage I have read a suggestion to disconnect the BMS if possible - > but don't forget to reconnect it when taking the battery out of storage. > > David Roden, EVDL moderator & general lackey > > To reach me, don't reply to this message; I won't get it. Use my > offlist address here : http://evdl.org/help/index.html#supt > > = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = > First they came for the journalists. We don't know what > happened after that. > > -- Unknown > = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = > > ___ > Address messages to ev@lists.evdl.org > No other addresses in TO and CC fields > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > ARCHIVE: http://www.evdl.org/archive/ > LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org > -- Michael E. Ross (919) 585-6737 Land (919) 901-2805 Cell and Text (919) 576-0824 <https://www.google.com/voice/b/0?pli=1#phones> Tablet, Google Phone and Text -- next part -- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20210725/a87a408c/attachment.html> ___ Address messages to ev@lists.evdl.org No other addresses in TO and CC fields UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/ LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org ___ Address messages to ev@lists.evdl.org No other addresses in TO and CC fields UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/ LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org
[EVDL] Charging my Volt from 100' of zip cord
TIP: Never be caught without wire! You can charge a Volt (8 amps default) via 100' of simple #18 lamp zip cord if you wanted to. (and had the 3rd GND wire). The 5v line drop is within the standard for acceptable voltage drop. I routinely carry hundreds of feet of #18 zip cord for backup and emergency power in all my vehicles because I can carry four times as much wire under the seat in the same volume as the standard stiff double insulated orange extension cords. See my spool: http://aprs.org/prius/photos/220cord3x.JPG Ignore the 220V label, this image was for when I remotely power things (universal power supplies) from the 220V prius battery. When I find such a spool, I pull off the 15' or 20' of stiff plastic orange cord and re-wind it with 100' to 120' of #18 lamp zip cord. Note: to get 120',you have to be very careful and obsessive in acting like a fishing reel and laying in the zip cord flat and adjacent (no twists). But you can do it. [But for dual wire use only - No GND wire] I showed up once at a downed tree and was able to plug in TWO of these 100' cords of #18 zip cord in series to run a small chain saw and save the day. Yes, there was noticible voltage drop but still plenty of power to run the saw. I have even run an electric lawnmower through one when it was more convenient than digging out all the old orange and green cords "from around back". Oh, also I was able to use two of these at a rest stop for a small space heater (on low-power (700W) and sleep in the car overnight (well, several hours anyway) because the black zip cord just kind-of disappeared in the joint to cross the sidewalk and then along the edge of the sidewalk around to the back of the building where the vending machines were plugged in. I would never have gotten away with that using 200' of bright thick orange extension cords. Anyway, just some tall tales from the armchair (never be caught without wire!) Bob, WB4APR -- next part -- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20210725/b264f612/attachment.html> ___ Address messages to ev@lists.evdl.org No other addresses in TO and CC fields UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/ LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org
[EVDL] Electric mower - small question
Friends, I have a quick question about figuring out the current capacity of a Consumer-marketed LiOn battery. I have been "driving" a small used B&D Lawn Hog mower for a number of years. A few years ago, I changed the switch in the handle, and now the rectifier needs to be replaced. While I am waiting for Amazon, I borrowed my neighbor's mower, which turns out to be a Ryobi running on 40V Lithium. Which started me thinking - considering my mower's motor is DC - what would it take to replace the cord + rectifier with some number of these 40V packs which are available at 6Ah? The motor has no plate but a search showed that it is rated for 12amps. If I use 3 of these batteries, the voltage will be matched, 120V, 6Ah. it would need those 3 batteries to run at the 2C level, which may not be sustainable. and, of course, for the price of 3 batteries, I could buy a whole new battery mower... but I really doubt I could run the same motor on 80 Volts, or 40 volts. (I'm not changing the motor at this time). So, it sounds like I will continue to be tethered for a while. Thanks -- next part -- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20210725/00803140/attachment.html> ___ Address messages to ev@lists.evdl.org No other addresses in TO and CC fields UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/ LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org
