1, Overcharge and overdischarge protection to prevent battery overcharge and overdischarge. Overcurrent protection to prevent abnormal high current of the battery 2, balance protection, battery voltage balance, extend battery life 3, stable heat dissipation, stable heat dissipation of aluminum substrate, safer 4, safety protection absorbs anti-high voltage, reduces MOS tube breakdown, ultra-low internal resistance MOS 5, suitable for most electric tools on the market, electric scooters, electric bicycles, electric tricycles, electric motorcycles, electric vehicles, electric tools, etc. Product Name: 4-String Lithium Battery Protection Board. Material: PCB + Metal Color: Silver Model: 4S 120A balanced with the same port-3.2v Continuous working current: within 120A Momentary working current: within 300 A Charging voltage: 12.8-16V Charging current: less than 50A Overcharge protection voltage: single cell 3.75V +/- 0.025V Overdischarge protection voltage: single cell 2.10V +/- 0.05V