Yeah, what Cor mentioned will work. You'd need to come up with something that can provide enough voltage to get the pack where you want it. Then it's simply a matter of connecting the contactor drive signals in the right order to get it precharged and then start pushing current. It's very important to closely supervise this and try to make sure that your setup cannot overcharge, as there will be no BMS intervention! It's a super bad idea to consider taking the cells over 4v/cell in this manual "bad boy" type setup. Something could go very wrong!
If you have a lab supply that can put out >350V that's a good idea. I use a Brusa NLG4 that's easily programmable for such tasks. It's also designed to charge EVs, so it's galvanically isolated and has programmable safeties. It puts out 3.3kW if you feed it 240vac. Numerous other EV on-board charger modules from a handful of OEMs have been reverse-engineered and details published on the web, so those are cheap solutions too if you have some programming skills. The OpenInverter forum has a lot if info: https://openinverter.org/forum/ An Arduino-capable dev board with CAN and a few hours of time and you can have a low-cost bench charging system for EV packs! You can also go with a "classic" bad-boy system. 240VAC mains with a bridge rectifier will put out about 320V peak, so it can be used to bring a low SoC Leaf pack up to about 3.3v per cell with low risk of overcharge. Can also do a dual-capacitor voltage doubler with 120V and get your 320VDC. Add to a variac with a boost output and you can get it to 50% SoC pretty easily. Don't take something like this on unless you really know what you are doing and what the consequences are. Or at least get a competent friend to take a look at your setup before you turn it on. It's totally OK to charge a pack with unfilltered rectified AC, In fact there is some research that indicates this is actually good for the chemistry in ternary cells. Tesla is doing exactly this on the Cybertruck. Note the lack of large filter capacitors in it's charger module: (Tesla calls this the PCS or Power Conversion System) https://ingineerix.com/pic/?tesla-cybertruck-pcs It's bi-directional, and uses planar transformers (windings made from the PCB itself!) It's a masterpiece of engineering. For those that are curious, here's the simplified schematic of one stage: (there are 2) https://ingineerix.com/pic/?cybertruck-pcs-basic Note no bulk filtering caps, or separate PFC stage! The 120hz ripple is just sent right to the battery! On Thu, Jun 20, 2024 at 9:17 AM <bvsp...@exchangenet.net> wrote: > On 2024-06-19 1:45 pm, (-Phil-) wrote: > > Not clear what you are asking here? Is it a separate pack you are > > trying to charge out of the car? > > yes. I can read it with leaf spy. out of the car. it has very few miles > and good SOH reading. > I was wanting to harvest the cells but charging them out of the pack > will be long chore. > > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20240620/0310138e/attachment.htm> _______________________________________________ Address messages to ev@lists.evdl.org No other addresses in TO and CC fields HELP: http://www.evdl.org/help/
