The battery management system(BMS), some called battery protect system(BPS), is a electronic system that manage inside cells of lithium battery pack.
The BMS mainly has 3 functions:
1.Monitoring the cells' voltage, current and temperature.
2.Protecting battery by preventing it from operating outside its safe operating area, such as:
①Over-current (may be different in charging and discharging modes)
②Over-voltage (during charging), especially important for lead–acid and Li-ion cells
③Over-temperature, the li-ion cells are sensitive to temperature
3.In order to maximize the battery's capacity, and to prevent localized under-charging or over-charging, the BMS may actively ensure that all the cells that compose the battery are kept at the same voltage or State of Charge, through balancing. The BMS can balance the cells by:
①Releasing energy from the most charged cells by connecting them to a load (such as through lights)
②Shuffling energy from the most charged cells to the least charged cells (balancers)
③Reducing the charging current to a sufficiently low level that will not damage fully charged cells, while less charged cells may continue to charge (does not apply to Lithium chemistry cells)
