The Leaf pack uses 2 parallel cells in their modules and all modules are in series, so in order to know the max amperage that the *Leaf* can draw (and presumably that is also the safe max value for the buddy paired cells) is to take the Power spec of the Leaf and divide it by the pack voltage. For example if it can deliver 170kW and the pack is nominal 340V then the pack is delivering 170,000/340 = 500A. Since the pack consist of 2 paralelled cells, each cell is delivering 250A in this example. That would mean that you need 4 cells parallel (or 2 modules) to safely deliver 1000A, similar to what the Leaf would do in this example. I don't have the specs of the Leaf handy, so please update the example with the actual numbers from the Leaf to calculate the actual cell load. NOTE that the cells's own specs might be lower than what the Leaf is pulling, since it is possible that the Leaf has other protections (temp, SoC, time, ...) that will protect the cells even when operated beyond their specs. I have worked on MC that (over-)loaded cells up to 4x their max spec. Those (NiMH) cells did not live long however... Hope this helps,
Cor van de Water Chief Scientist Proxim Wireless Corporation http://www.proxim.com Email: [email protected] Private: http://www.cvandewater.info Skype: cor_van_de_water Tel: +1 408 383 7626 -----Original Message----- From: EV [mailto:[email protected]] On Behalf Of Ben Goren via EV Sent: Friday, October 10, 2014 11:53 AM To: Roland; Electric Vehicle Discussion List Subject: Re: [EVDL] Need Lithium batteries. On Oct 10, 2014, at 10:12 AM, Roland via EV <[email protected]> wrote: > These are the batteries from the Hybrid Auto Center that I am going to use. You can get them preassemble or unassembled in metal case modules that contains four cells each connected two in series and then two in parallel for a voltage of 4.2 volts per cell or 8.4 volts maximum per modules at 66 a/h each. What would the maximum discharge / C rating be for those cells? Or, conversely, how many would you need to gang together to safely pull a thousand amps (round number) for several seconds? 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/20141010/9652 3170/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)
