This battery pack applied special designed protection circuit： Over charge, Over discharge, Short circuit and over current protection.Prevent battery from fire and explosion. 2）Protection IC： The protection IC with real time detection function: over charge ,such as over discharge ,over current and short circuit protection. It ensured battery security and stability. 3）Temperature detection switch ： This part was designed for high temperature protection of battery. If the battery temperature up to 75±5℃, the temperature switch will cut-off the circuit to protect the cell. 4）Li-ion Cell：18650/2200mAh/ 3.7V 5）MOSFET： MOSFET，it keeps the voltage between the positive and negative conversion in a stable situation. 6）Battery pack will packaged in sealed plastic case www.m-battery.com