Several folks have made LED indicators that light at different voltages. Here is one example I came across quickly. I have some other cool examples buried in my computer (somewhere).
http://www.youtube.com/watch?v=cHlq1J5dbb4 On Fri, Feb 15, 2013 at 11:14 AM, Pestka, Dennis J < [email protected]> wrote: > If you don't go the BMS route, does anyone make a good reliable instrument > to monitor ~ 50 cells. > You wouldn't think it would be that hard to make some visual > display/meter/instrument/? that would let you keep an eye on 50 cells. > That way, if you're concerned about a BMS and all the issues we've heard > about, you could take it on yourself to monitor the cells. > > Anything available out there that I'm missing ? > > Thanks; > Dennis > Elsberry, MO > http://www.evalbum.com/1366 > http://www.evalbum.com/3715 > > > > But suppose there is no BMS. Lithiums do not have the large resistance > increase as they approach dead. The weakest cell keeps right on trying, > right up to a few moments before it drops dead. At the 10.5v cutoff, you > may have 3 cells at 3.1v, and one at 1.2v. The 1.2v cell's voltage won't > bounce up to a "safe" voltage range. It has been seriously damaged, and > won't recover. And without a BMS, you won't *know* you've damaged it, > and may blithely keep using it, potentially leading to a fire! > > So that's the situation as I see it. When everything is fine, it works. > When something goes wrong (like the cells wandering out of balance, or > leaving the lights on, etc.), there is a risk of failure. If things go > very wrong, the failure can be dramatic! > -- > For every complex problem, there is a solution that is simple, obvious, > and wrong. -- H.L. Mencken > -- > Lee A. Hart, http://www.sunrise-ev.com/LeesEVs.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) > > _______________________________________________ > 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) > > -- Marcus Reddish *North Valley Systems LLC* Stevensville, Montana 406-360-8628 northvalleyev.com -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20130215/0380092e/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)
