Hello Jay,
Parallel three modules is like paralleling six cells. This is what I did. Unlike all the cells being in series the full battery ampere is felt by all the cells. Lets say you ever get the battery ampere up to 600 amps if you are going to drag race, the maximum cell ampere will be 600/6 = 100 amps. I did a long drive yesterday going up a 5 mile slope at 40 to 50 mph. On acceleration the battery amp never went over 100 amps and the motor ampere is about 300 amps. At a constant speed, the motor ampere is held at 180 amps, the battery ampere at 60 ampere and the six cells in parallel are 60/6 = 10 amps per cell. So there will be no problem with three modules connected in parallel. After the run of 10.4 miles, it took 29.2 ampere hour. Charge the battery pack with a PFC-50 charger set at 30 amperes and it took 65 minutes to charge. The battery temperature before the run was 70 F. Turn on the battery box exhaust fans which brought in cool 55 F. morning ambient air. Let the EV set for two hours and the battery temperature was at 68 F. The ambient air was above 80 F between the space of the glass hatch back and the double layer battery box. Turn on the hatch fans to exhaust this air back to 72 degrees. Did not turn on the battery exhaust fans which may bring in a higher temperature than the battery temperature. On the return trip it was a down hill run with some level driving. The battery and motor ampere is 0 to about 30 amperes which is about 0 to 5 amperes per cell. The battery temperature at home was still 68 F!!! and was still about that temperature after charging. It is best not to remove the cells from the aluminum cases, because the aluminum cases act like a heat sink and the cells are space from the ends of the modules for air ventilation through vent holes. The modules are assemble together with about 1/8 to 3/16 inch space for air circulation. Each battery pack block should be space apart for air circulation and exhaust venting. The modules should not be touch the sides of the battery box container. I leave about 2 inch space between the modules and about 5 inches between the modules. Roland ----- Original Message ----- From: Jay Summet via EV<mailto:ev@lists.evdl.org> To: ev@lists.evdl.org<mailto:ev@lists.evdl.org> Sent: Tuesday, March 31, 2015 8:01 AM Subject: Re: [EVDL] Seeking Advice: Reusing the battery modules from a Nissan Leaf On 03/31/2015 09:12 AM, via EV wrote: > Anyone know what the maximum discharge rate is for the Nissan Leaf > batteries? > No hard facts, but here are my estimates: The Nissan leaf battery is made up of 48 modules, each providing 7-8.2 volts at 60Ah, for a total of 390-400 volt max @ 60Ah or ~24 kWh. The leaf motor is rated at 80 kW, and the battery pack is supposed to be able to provide up to 90 kW (motor + all accessories), which at maximum voltage would be 228 amps. This is around 3.8 times C (60Ah) which seems to be easily in the realm of possibility, and matches up with the fact that the fuse in the leaf battery pack is a 250 amp fuse. Individual modules MAY be able to provide 10C (600amps!) for a short period of time, but may also burst into flame or just die quickly if asked to do so....I wouldn't recommend it! I expect that they can provide a solid 3C rate for a relatively decent amount of time (30 seconds anyways) without any serious ill effects in the long term, which is very much in line with other lithium batteries. For my application (S-10 pickup at 120 volts) I'll rarely need to go over a 300 amp draw (typically 50-100 amps continuous) and am planning on arranging them in sixteen series packs of 3 parallel modules, giving a 180-190 Ah battery at close to 120 volts. So my max discharge will probably be closer to the 1.7-2 C rate which feels relatively conservative to me. Jay _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub<http://www.evdl.org/help/index.html#usub> http://lists.evdl.org/listinfo.cgi/ev-evdl.org<http://lists.evdl.org/listinfo.cgi/ev-evdl.org> For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/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/20150331/92d4350e/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)
