Bullet-proof >100A 16S BMS

[tewasch]

Apparently I have burned-up two JBD AP21S01 6S-to-21S BMS systems. In both cases, it happened when programming parameters using the XiaoXiang APP (For example, I was adjusting the 20/40/60/80% points). I got smoke from overheating the first few channels of the sensing/controlling circuits by burning-out some of the 510 ohm and 1K resistors. The conformal coating is brown now.

A.) I have no idea why this consistently kills the BMS--anyone understand this? and,
B.) are there more-recent model suggestions of a rock-solid BMS for a 48V, 16S over-100 Amp application today?

I have 16 new and perfectly top-balanced 304 AHr LiFePO4 EVE cells. The BMS ran beautifully. All cells within 30 mV. I ran the pack up and down just fine. The fully charged state was reading 18% capacity so I re-programmed the percentage SOC parameters and poof...

Suggestions would be really appreciated.... Tom.

 

[HRTKD]

Whatever you're doing, stop doing it. I suspect that the number of forum members that are changing the state of charge increments is really, really small.

Buy a BMS from the Overkill Solar site. Before you change any more parameters, check with them to see what they say about it. At the very least, their warranty will have you covered when you kill another BMS. The JBD BMS has been tested to be quite reliable, so if you're killing it, you're doing it wrong.

 

[tewasch]

Yes, thank you. I had already contacted Overkill Solar this morning. The default settings in the JBD unit I received had 100% at 4.2V down to 20% at 3.4V which were way off (and way off from the settings documented in the Overkill Solar write-up). I attempted to change them to the settings in the Overkill Solar write-up and poof. I think it was because I was connected to my Growatt at the time I re-programmed (although, the inverter was switched-off). When re-programming, this must back-flow current out the sense resistors or something such that the lower sense lines cook. Its a mystery to me. Of course, there is no documentation that tells you what you can and cannot do and when. Hmmmf. I expect it would have all worked find had I disconnected everything (load and charger) from the battery/bms before attempting to re-program.

Thanks for your thought. I sent an email to have a small conversation with someone at Overkill Solar before I order one. I've built other batteries before (with JBD BMS) but they were 4S and were very straightforward. This is my first 16S build. Tom.

 

[Browse]

Off Grid Garage tested a bunch of BMS models and found that this one was his favorite

 

[tewasch]

Just as a follow-up. I did replace the 6S-21S BMS (direct from JBD) with the 16S one from Overkill Solar (after a very nice conversation with them). It worked perfectly the first time and continues to work well. I now use their App (Android) and had to re-program the parameters for my pack size and a new device name.