BMS defect or unbalanced cells

[e-beach]

if my cells are unbalanced and i just plug my bulk charger when certain group of cells reach 4.20 volt will it damage them to let the charger charge the other group of unbalanced cells ? or should i let it charge until all groups are at 4.2 volt ..?

The answer to that could be yes or no depending on what you are doing or not doing. If you are watching one group of cells and another group goes over 4.2v then yes you can damage the group that got over charged. Search using the google search box at the top of the page for battery charging and start reading. It could help you not burn your house down.

 

[Voltron]

Yes, just bulk charging with them unbalanced is bad. If you're going to go that route, you need to either use small lightbulbs or something to discharge each of the high groups, but you really need to stay near it and not forget you're draining a group and let it go too low.

Or charge up each low group one by one with a charger on a 1s setting. You could also use a 5v USB charger, but then you again have to really really watch it so it doesn't overcharge.

But just plugging in a bulk charger till it turns off, on an unbalanced pack, with no BMS, is a BIG no.

 

[CanadianKid]

thanks i kinda figurred it out myself monitoring the bms it cut starta bleeding at 4.20 volt and at 4.25 volt it trips the bms overvltage protection.. Im charging every cells with my isdt q6 trough the balance leads.. 40 ah 20 s.... lol pretty long