When you're on the go and you don't have time to charge your phone before leaving, bring along a Fosmon premium quality spare battery. It is a rechargeable lithium-ion battery that is specifically designed for your device. It has a longer battery life than the original one that comes with your device. This battery is equipped with a built-in battery life microchip for overcharge protection. It can be charged or discharged as needed without the loss of capacity. Now, you never have to worry about low battery life again.