Ben, Why on the world would you need over 200kW unless you are doing a race car? Around 50kW gives you a system that keeps up with traffic and 100kW gives you plenty power for all daily driving conditions and would not put the Mustang to shame, even though you might not win off-the-line from muscle cars - but I had the impression that was not your goal.
These days I am driving a truck that tops out at about 35kW. Certainly not high performance by any measure, but I can commute with it, not annoy too many people when I drive on the freeway and it give me the utility that a truck has - all the load carrying capacity of the 7 foot long bed. The 20 Golfcart batteries are happy with the current limit so they are not over-extended to much pushing this heavyweight around - the only thing that occasionally gets overextended is my patience, but it is a learning process and until I get around to install a parallel pack of Lithiums and BMS, I am going to stay within the boundaries that keep these batteries happy. Before this truck, I had a US Electricar that had 60kW power and certainly could keep up with traffic even though it weight a total of 5,000 lbs (driver included) My suggestion: use half your pack size (are there 90 Ah cells that you can use instead of 3 strings of 60?) which gievs half the cost and capacity, as you indicated that is what you need. Success making the trade-offs. Cor van de Water Chief Scientist Proxim Wireless Corporation http://www.proxim.com Email: cwa...@proxim.com Private: http://www.cvandewater.info Skype: cor_van_de_water Tel: +1 408 383 7626 -----Original Message----- From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of Ben Goren via EV Sent: Friday, July 25, 2014 2:59 PM To: EVDL Administrator; Electric Vehicle Discussion List Subject: Re: [EVDL] Hybrid Mustang: batteries On Jul 24, 2014, at 9:57 PM, EVDL Administrator via EV <firstname.lastname@example.org> wrote: > I think Ben G can build this car. However, I'm not sure he's going to get > absolutely everything he wants (range, power, price). > > As with so many other things : go far, go fast, go cheap : pick two. :-\ I'd love to pick just two! Sadly, it looks like "go fast" is coupled to the other two.... Thanks to the people here, I've spent a lot of time today so far searching and crunching numbers and the like -- dozens of batteries from half a dozen vendors and as many manufacturers (including CALB, Enderel, GBS, and more). I'd appreciate if somebody can check my math on the current leading candidate. It's a Voltronix 3.2V 60Ah 8C cell that EVWest sells for $78 / ea: http://www.evwest.com/catalog/product_info.php?cPath=4&products_id=266&o sCsid=ph57045uael6qb57sjjaqi8cs3 If I have the math right, if I were to connect 45 in series, that would make a 144V 60Ah cell. Three of those in parallel would make a 144V 180Ah battery capable of 1440A discharge and thus 207kW power with a total capacity of 26kWh...at a total cost of $10,530 and a weight of about 750 pounds. Does that math sound reasonable? That's twice the capacity I need, which obviously in and of itself isn't a bad thing. But that's over twice the cost I had previously been guesstimating -- and doesn't include a BMS or charger or the like. And it's a *lot* of weight. But if I cut back on the number of cells, I cut back on either voltage or amperage (or both).... It looks like a GBS system in a kit with BMS and the like would likely get similar performance with half the capacity and a third the weight...for twice the money. Enderel looks to be about comparable to GBS but maybe lighter and more expensive still. So...um...am I missing anything? Thanks again, everybody. 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/20140725/b248 2853/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)