Thanks for the clarification. However spot welded packs have an advantage. I'm very interested in doing one. Seems the voltage and capacity of each cell must be identical when the module is put together. Tesla is using them so a spot welder is in my future. Lawrence Rhodes
>________________________________ > From: Lee Hart <[email protected]> >To: Lawrence Rhodes <[email protected]>; Electric Vehicle Discussion >List <[email protected]> >Sent: Tuesday, September 3, 2013 8:29 AM >Subject: Re: [EVDL] Questions about Lithium batts for a VERY light car-- under >600 lb w/o batteries > > >Lawrence Rhodes wrote: >> Lee I'm surprised you would say using less cells when you probably meant >> to say less amp hours. If you want 144vdc you are stuck with 45 cells. > >The original poster asked about different lithium chemistries. I said that >3.6v LiPo cells have higher power and energy density, so a pack with a given >acceleration and range would be smaller and lighter. However, these cells only >come in small sizes (like laptop 18650 cells), so he'd need a very large >number of them (many cells in parallel). This causes wiring and reliability >headaches. > >3.2v LiFe cells have lower power and energy density, so a pack with a given >acceleration and range would be bigger and heavier. But it's easy to get them >in higher amphour capacities. They are also safer. So this is the type of cell >I would use. >-- >A designer knows he has achieved perfection not when there is >nothing left to add, but when there is nothing left to take away. > -- Antoine de Saint Exupery >-- >Lee A. Hart, http://www.sunrise-ev.com/LeesEVs.htm > > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20130903/9947bd81/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)
