NO, we don’t know that yet. It’s a possibility.
@markyoe still needs to try a different charger
And it’s possible maybe the charge needs to be on N- port
I have that exact bms, and that is the behaviour. One cell hits 4.25, that’s it, no more charging.
I think this is proper behavior. That cell I. Already high at 4.25.f it lets charge keep going there’s a good chance the high cell overcharges. The tiny bleed resistor which can do 50-100ma has to compete with the charger which can be throwing as much as 4a/10cells==400ma at the cell assuming a 4a charger and 10s pack.
When this happens, does it start balancing? Discharge all cells to the same voltage as the lowest cell?
It should stop charging and start bleeding the higher cells to match the lower ones and start charging again, but this doesn’t happen. That’s why some of us moved from analog BMS to digital ones. Much more customization, better charging/balancing algorithms, etc.
2 Likes
Just an idea, what is the N- port for and what happens if you connect the charger negative to it
Warning: I don’t know for-sure that’s safe, but if I was in your position I would try it, closely monitoring EVERYTHING and see what happens. Maybe first through a fuse.
edit: I was just told by Bestech that if a BMS has a N- it’s probably the charge port.
@markyoe So try moving that black wire from P- to N-
1 Like
Well dang, lol. Thanks for checking in on that. I was about to email Lilian to ask about that. I’ll do that and report back what happens.
2 Likes
I manually charged the P-packs with my B6 before I knew to change the negative cable to N- so I’m not totally sure if changing it was the solution. I’ll be using the board quite a bit the next fews weeks so we’ll see if the BMS will actually keep the packs from drifting.
1 Like
I would drain one pack down a little bit just to see if the BMS will correct it…
2 Likes
Awesome job on the troubleshooting assist @b264. I have been follwing this just to see how it all turns out. Hopefully it is all sorted now @markyoe
2 Likes
Any updates on how the BMS is performing? I’ve been having a problem with my bestech BMS and unbalanced P-groups. How did you fix it?