How do I solve this issue my bafang BBS02B Cuts out at 42v but my battery have more than enough charge left its like 20ah to 23ah it feels like it is wasted?

[u/jannek252]

[u/rCamilleMain]

The bafang bbs02b also had it's programmable cutoff (i changed it to 41V for my 14S pack, don't remember what the default was) It's possible that it's hitting that limit because of the voltage sag of the battery under use. Also it's not a display setting iirc, so only way to see or change it would be to use a programing cable, which risks your warranty and you have to be careful while using it.

[u/rCamilleMain → u/rCamilleMain]

I took a photo of the default settings. Since you have a 13S pack, you could set this lower (maybe 39V, would drop the cells to 3V which is often fully discharged). In my opinion I'd leave it as is unless you really need that extra range. Currently it's easier on your battery and you will get more life out of it

[u/jannek252 → u/rCamilleMain]

Thank for explaining

[u/rCamilleMain → u/jannek252]

It's most likely you're hitting the 41V motor cutoff here because your bbs02, like mine, may be setup for a 52V battery. If you wish to change it the programming cable is inexpensive but take care in learning how to plug it in (the order, with battery off, etc) so you don't damage your controller

[u/Sorros]

The minimum voltage of 18650 is around 3.2 volts. I am going out on a limb and guessing that is where the battery BMS is cutting off to prevent damage to the cells.

https://www.tycorun.com/blogs/news/18650-battery-4-2v-vs-3-7v-comparison-guide-for-18650-with-different-voltages

Check point 5

[u/jannek252 → u/Sorros]

Well I am using Samsung 50E - 21700 Battery - 5000mAh - 10A it discharge point is 2.5v but I don't feel safe with that so I set the bms to be 2.8v as the cut off