Can be applied to various 3.7V lithium core. High-accuracy voltage detection circuit, fine workmanship and durable,compact size and lightweight. Over-discharge protection, overcurrent protection, overcharge protection, short circuit protection functions. Built-in three-stage over-current detection circuit (over-current 1, over-current 2, or load short circuit) Applicable to : vacuum cleaner, massager battery pack, LED light backup power supply, 12V electronic products, solar street light battery pack, monitoring standby power supply, etc. Specifications: 3 string :for 3 18650 batteries or polymer lithium battery series combination 10.8V (Rated voltage of polymer battery) 11.1V (18650 or 3.7V lithium battery rated voltage) 12.6V (Lithium battery full charge voltage) Charging voltage:12.6v ~ 13v Over Charge voltage:4.25 ~ 4.35v Over Discharge voltage: 2.3 ~ 3.0v Max Working current:6 ~ 8A Max peak current:10 ~ 13A Internal resistance: Less than 100mΩ Working temperature:-40 ~ +50 Storage Temperature:-40 ~ +80 Quiescent current: