My experience (limited and dated to be sure) is you get what you pay for. In particular, a cheaper pack with a no name source, the cells may not be well matched in capacity and the BMS may be total crap. I tried to carry on conversations with a couple suppliers at this tier and found that they knew almost nothing about the cells they used, or how to test them to see if they had any quality and consistency. They offered graphs and specs that made no sense at all. Axes not labeled, missing information, etc. I believe they were running long tests at levels that would never damage or detect a defective cell, but they had a lot of repititions so it sounded OK. If you don't know much about the cells in your packs, then you can't set up the battery management so it does a good job.
Its a jungle out there. On Mon, Mar 11, 2019, 9:35 AM Dan Baker via EV <email@example.com> wrote: > Hello EVDL members > > I'm looking at replacing the lead pack on my pontoon boat this year with a > much lighter lithium solution. I see on Aliexpress that they have 12v and > 48v 100ah packs with built in BMS that look be the best prices I've seen. > These are brands I have not heard before (GTK/Demuda, etc) The area I live > in doesn't have a lot of EVs so finding used cells for DIY is quite > sparse. Anyone have any experience with purchasing packs from Aliexpress, > are they any good? > > Thank you > Dan > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: < > http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20190311/d5e90aed/attachment.html > > > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > Please discuss EV drag racing at 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/20190311/38980158/attachment.html> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)