1,Overcharge and discharge protection to prevent overcharge and discharge of the battery. Overcurrent protection to prevent abnormal high current of battery 2,Balance protection, battery voltage balance, make battery life longer 3,Stable heat dissipation, stable heat dissipation of the aluminum substrate, 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 strings 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 300A Charging voltage: 12.8-16V Charging current: within 50A Overcharge protection voltage: single cell 3.75V+/-0.025V Over-discharge protection voltage: single cell 2.10V+/-0.05V Short circuit