Hi.
Have a few lithium battery packs from unknown origin, labeled 12.8V 10Ah Pulsa brand which cannot find data. There is 20 18650 cells in it and a management board inside. Only one 'barrel' wired connector to the external world. That is, same wire pair path for charge and for discharge.

I applied 11.5V to the barrel and charged to about 11V overnight.
Is there a range of voltages that should be applied for safe charging operation ? Would the management board take care of that ? Up to what voltage ?

 

I guess the battery cells are LiFePO4 type that average 3.2V each during a discharge, 4 cells in series then 5 rows in parallel.
The management board might be simply a protection board then a charger is separate. But the board might include a charger.

 

Thanks.
Correct, series of 4 groups of 5 paralleled cells. 4x3.2V = 12.8V
Will feed 14.8V for a short time and watch if its management stabilizes them by 12.8V

 

The battery is probably only partially charged at 12.8V, it is probably 4 x 3.6V= 14.4V when fully charged.

 

If the cells are name brand, you can search the part number and find specifications.