Note: The positive pole of the battery is connected to B+ and the negative pole is connected to B-, do not reverse it. If it is reversed, it will burn out!!!! This module is a portable backup power supply with an input that matches the 5.0V adapter to charge the internal battery. Use built-in battery for portable device to provide 5.0V/3.0A USB2.0 supply output for external devices. Protection: overcharge protection, overdischarge protection, short circuit protection, constant current. Charging cable: support three USB data cable charging, including Iphone and Android. Size: 6.5 2.5 0.1cm; Dual output current: 5V 2.4A; Input voltage B+ to B-: 3.0 - 4.2V.