Hello,
with a bordering probability it is certainly a "secondary protection" system, which protects the cells against deep discharge, overcharging and excessive current.
DejayPablo wrote: There is a Balance Charging Board in the description
It is quite possible, but in such PCBs balancing is quite often done in an extremely idiotic way, probably only to be able to write "there is balancing of cells".
DejayPablo wrote: So how to safely charge them?
the best balancer?
If the balancing on the PCB is fictitious, it's best to throw it out at all. For charging, you should use a specialized charger (CC / CV) with parameters appropriate for your cells. The charger should have a balancing that will function reasonably.
DejayPablo wrote: what's the point? Charger / Load?
Probably yes, it is difficult to say without a pattern.
DejayPablo wrote: Does anyone have a manual for this?
It is rather a dream of a severed head. You can try to search on the web, maybe someone recreated the diagram from the board.
You may as well recreate the scheme from the tile yourself. The circuit is quite simple (the cell protection circuits just have to be simple hardware circuits), the detection circuits are usually quite typical (Ricoh, Seiko), the documentation is available on the web. The transistors are also rather typical (probably n-mosfets), connected in parallel to obtain a higher allowable current.
best regards
