Charger to weak? For12s12p - using BMS

I built a 12s12p (42V, 31Ah) 2600mAh battery pack that I want to charge. A BMS is connected.

I tried to use my little and lightweight ESK8 charger (41V, 2A) charger and I have the feeling that is doesn’t charge. Neither directly on the plus and minus nor via the BMS.

My question:
Is the charger too weak?

Thanks for your help

Maybe check BMS spec first?

Is your esk 10s or 12s? 42v charger sounds like 10s charger. I would expect you need a 50,4V charger if you have a 12s battery pack

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Good point. I have just checked. The skateboard is 10S5P. I have no real clue about charging theory, but I can imagine that the charger is too weak.


Anyways, 2A will take forever to charge a battery of this size. 15A would allow you to charge it in around 2h.

If you have no clue about charging, you should first check your fire insurance of your house!!


This is really true. In the years of Lipo charging, I have made also bad experiences. This is why I charge the foil battery only open air on concrete.

With the DIY Foil, questions arise, that I never needed to ask as in the RC world, you have charging programs with built in balancers.It is self explanatory. Here you need some more background.



Can’t charge a 12s battery with a 10s charger (if that wasn’t clear already?)

12p of 2600mAh is 31.2Ah so it would take more than 16hours to charge at 2A. You can google “CC-CV charging” if you want to know more about the charge profile.