Specifications: Charging voltage:4.2v Over Charge voltage:4.25v plus or minus 0.05v Over Discharge voltage: 2.45v plus or minus 0.05v Max Working current:4A Max peak current:5A Working temperature:-40 ~ +50 Celsius Storage Temperature:-40 ~ +80 Celsius Internal Resistance:MOSPET less than 40m ohm Life cycle:more than 30000 hours Short Circuit Protection: Protectable, Delayed self-recovery Size:35 mm4mm2.2mm/ 1.38 0.160.09(L x W x H) Suitable for: For nominal voltage 3.7V lithium battery(Including 18650,26650, lithium polymer batteries) Attention: 1.Strictly according to the diagram wiring: B+: connected battery positive, B-: connect to battery negative, P+: connection charge / discharge positive, P- connection charge / discharge negative, Otherwise it will cause damage to the chip. 2.After connection,it need to first charge activation, then will have the output. Package inlcuded: 5x 1S lithium Battery Protection Board HIGH-ACCURACY, HIGHLY DURABLE: High-accuracy voltage detection circuit, fine workmanship and durable, Effective life greater than 50000 hours. MULTIPLE PROTECTION: Over-discharge protection, overcurrent protection, overcharge protection, short circuit protection; A combination of 4 safety features that work together to provide ultimate protection for your devices, your chargers and most importantly:you. LOW STANDBY CURRENT: MOS transistor can control the battery charge and discharge, low standby current consumption. WIDELY APPLICATIONS: Use for variety of capacities and various shapes 3.7V lithium batteries,Massager battery pack, LED light backup power supply, solar street light battery pack, monitor standby power supply, etc. ATTENTION: Strictly according to the diagram wiring: B+: connected battery positive, B-: connect to battery negative, P+: connection charge / discharge positive, P- connection charge / discharge negative, Otherwise it will cause damage to the chip. After connection,it need to first charge activation, then will have the output.