Steve, I watch EVTV off an on. They are into golf carts and have a LiFePO4 pack that will probably never fail - which is to say, last longer than a several carts perhaps. I believe it has a BMS built in. You might see if you can find the weekly show last year where Rickard showed in depth what they put into them.
I am sure they are a premium package, but you might see something about them that you like - or maybe you can deal with the higher cost balanced by really good performance and reliability.. On Tue, Sep 16, 2014 at 10:31 AM, Steve Clunn via EV <ev@lists.evdl.org> wrote: > I am working on some Golf Carts and portable 12V power packs that get used > sporadically and may sit for months without use. > > I have contactor on one 12V and 36V that draws about 1 amp. The problem > is, if everything is happy, the Mini BMS Circuit keeps the contactor ON. > Which draws enough current, that at some point, will drain the battery > down. > > I am trying to come up with a way that the owner can walk away from this > system, and come back to it and have it ready to go without having to > switch switches OFF and ON. > > One thought I have had is to set it up with a transistor that controls the > contactor. And after so many hours, will turn OFF the contactor. My > thought was a Mosfet with a large Capacitor and a Momentary switch to > charge the capacitor which would keep the contactor ON for maybe 10 hours > while the Capacitor slowly drained down. > > Of course, the operator will have to engage this each time he uses the > battery, but at least it will turn its self off automatically. > > I am wondering if anyone has any other ideas... that doesn't involve a > micro processor. > > I am noticing that the smaller the parts that I am working on....the longer > it seems to take ! > -- > Steve Clunn > Merging the best of the past with > the best of the future. > www.Greenshedconversions.com > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: < > http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140916/31d890b6/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) > > -- Put this question to yourself: should I use everyone else to attain happiness, or should I help others gain happiness? *Dalai Lama * Tell me what it is you plan to do With your one wild and precious life? Mary Oliver, "The summer day." To invent, you need a good imagination and a pile of junk. Thomas A. Edison <http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html> A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 550-2430 Land (919) 576-0824 <https://www.google.com/voice/b/0?pli=1#phones> Google Phone (919) 631-1451 Cell (919) 513-0418 Desk michael.e.r...@gmail.com <michael.e.r...@gmail.com> -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140916/5854afaf/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)