Hello Tom, I selected these batteries to increase the voltage and reduce the weight. My first set of batteries was 300 ah cobalt cells with a maximum charge voltage of 252 volts similar to the Exide Tudor Cells which weigh 30 lbs each. The total weight of the battery pack was close to 3000 lbs that included two large 1/4 inch thick aluminum battery boxes. These battery boxes were later change to epoxy fiberglass.
Had no problem driving to work up steep hills keeping up with the traffic at 75 mph. The battery ampere at this speed was about 180 amperes. I squeeze 10 years out of these batteries. No longer had to drive out of town to work, all in town driving, but there is no level streets in my town. I replace these batteries with Exide X 245 ah 6V for a 180 volt battery pack. Level driving battery ampere was about 90 amps, but the hill climbing was over 200 to 300 amps which was about 50% of the drive during that time. Increase the voltage to 216 volts which had some what better performance, but the weight of the was over 7500 lbs. Did not get over 5 years with these batteries. My next battery pack was the Trojan 6 volt 245 AH at 180V which lasted 8.5 years. Did not have to drive a 5 mile road that incline's up hill for that distance. The last pack I have now, is the U.S. 6 volt 252 AH at 180V that has about 6 years on it. These do not have the performance that the the Trojans have. Very weak acceleration on slight rises on hills, on level grades the performance is still normal. Giving these batteries to a person that is building a EV which will weigh half of my EV using 20 of the best ones in this pack. Roland ----- Original Message ----- From: tomw via EV<mailto:ev@lists.evdl.org> To: ev@lists.evdl.org<mailto:ev@lists.evdl.org> Sent: Saturday, October 11, 2014 8:01 AM Subject: Re: [EVDL] Need Lithium batteries. Hi Roland, I never thought I'd see you buy lithium-based cells. Lead acid seemed to work very well for you...was it mainly to reduce weight? David, If you look at the discharge curve on the hybrid auto center site, max voltage is 4.2V, the average cell voltage is around 3.7V to 3.8V, and they are discharged to around 3V to remain above the "knee" of the curve where V drops more quickly with Ah used. Their mass is 3.8 kg/module, so kWh/kg is about 2*3.8V*66Ah/3.8kg = 132 kWh/kg. Liyuan sells some cells that are over 140 kWh/kg (mainly due to lighter packaging I think), but much more expensive - on the order of $1.50/Ah - CALB has similar, the CAM72 cells which are about the same price from Keegan, much higher from Jack R. These Leaf cells are different chemistry than the more common (among DIYERs) LiFePO4 which has the voltages you mentioned. -- View this message in context: http://electric-vehicle-discussion-list.413529.n4.nabble.com/Need-Lithium-batteries-tp4672019p4672054.html<http://electric-vehicle-discussion-list.413529.n4.nabble.com/Need-Lithium-batteries-tp4672019p4672054.html> Sent from the Electric Vehicle Discussion List mailing list archive at Nabble.com. _______________________________________________ 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/20141011/a2e290cb/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)
