With over charge, over discharge, over current, short circuit protection function, for a variety of different shapes of 3.7V capacity lithium batteries. Well-designed, comprehensive test. Compact size, suitable for many requirements of high integration, low cost occasions, can meet the performance requirements of many aspects, to ensure the absolute safety of the battery group. 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 mm×4mm×2.2mm/ 1.38? ×0.16?×0.09?(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