i just looked for the datasheet for the board but couldnt find it. There must be a datasheet to show you where the charger power source will be connected.
By the looks of it, there are not "Power" componments on the PCB, so i guess its just checking the voltage on each cell and not doing any balancing.
But that can be fine if the cells are well matched, and even if they are not matched, it might just mean you only get up to 80% of full charge, which might still be ok?
But please post datasheet if you find it...then we can assess it.