JZK 5PCS 2S 7.4V Lithium Battery Protection Board Module, 7.4v 8.4V 2S BMS PCM Charge Discharge Protection Board for Li-Ion Lipo Battery 18650. High-accuracy voltage detection circuit; Terminal of the charger using high voltage device; Built-in three-stage over-current detection circuit (over-current 1, over-current 2, or load short circuit); MOS transistor can control the battery charge and discharge; Low standby current consumption. Over charge voltage:4.25-4.35v±0.05v; Over dishcarge voltage: 2.5-3.0v±0.05v; Max. working current 8A; Max. peak current:10A; Working current 8.4V - 9V; Working temperature: -40---+50°C; Storage Temperature: -40-- +80°C; Quiescent current: less than 10uA; Internal resistance: Less than 300mΩ; Life cycle :more than 50000hours; Short cut protection : yes, charge can repair; Size: 41*16*3.5mm; Connector: B+ Connect battery positive; B- Connect battery negative; MB Connect the point between battery1 & battery 2; P+ Charge/discharge positive; P- Charge/discharge negative. Reminder: When combining batteries, the voltage, capacity and resistance of the batteries should be well matched. The battery voltage should be around 3.7V at the rated voltage. There is no output after the battery pack is assembled, and it can be charged with 8.4V voltage.