Funtion battery power on the go for smartphones and usb devices the recharge 2500 is a portable usb power bank with the latest li polymer battery technology built in that will fully charge smartphones and many usb devices whether you have access to power or not the recharge 2500 is a pocket sized yet easy to use device just connect your usb charging cable to the usb port and press the power button charging will start instantly the built in 2500mah li polymer battery will fully charge yo