Many of the BMS systems out there are using chips designed for Laptop and power tool packs where the BMS disconnects the pack from the load or charger to prevent high/low cell voltage or overcurrent. Due to their low cost, they have been 'beefed up' for high current use that is not really appropriate. Having your battery disconnect under load, or particularly under regen, will void the warranty on most controllers. The BMS should signal the controller or charger to reduce current.
I've been playing around with one of the cheap BMS units and modifying it for external interfacing. https://youtu.be/1N3kWStCo-s On Fri, 22 May 2020 at 06:04, Lawrence Rhodes via EV <ev@lists.evdl.org> wrote: > > It seems most battery pack builds use one bms per cell row. That is two or > three batteries in parallel using one BMS. If I am using A123 batteries that > could be up to 120amps for 2 in parallel. Must the BMS be rated for the full > 120 or would I go by the rated amps of the controller which in my case is > 40amps? How many batteries in parallel can I safely put on one BMS? Any > recommendations for reliable BMS? Lawrence Rhodes > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: > <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20200522/b414cedf/attachment.html> > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > ARCHIVE: http://www.evdl.org/archive/index.html > INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org > Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA) > -- Paul Compton www.morini-mania.co.uk www.paulcompton.co.uk (YouTube channel) _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/index.html INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
