Each 12V battery pack consists of 4 LIFEPO4 battery cells and a intergrated battery monitoring and charging system (BMCS).
The BMCS monitors the battery pack and each indiviual battery cell.
The battery pack contains an integrated balance charger. The battery pack charge port only needs to be connected to a constant current power supply. The integral single cell chargers balances each cell individually until the required charge state has been reached and all the battery cells are charged equally.