Cellet 1900mAh Portable Backup Battery Charger, micro-USB Compact size convenient for storage and travel; Quickly and efficiently charges cell phone and smartphone. Includes status button to show remaining battery power; Backup battery capacity LED indicator. 1900mAh high-capacity rechargeable lithium-ion battery; Output: 5V, 800mA. Pass-through charging allows the Backup Battery and phone to charge simultaneously; Recharge Backup battery with your existing phone charger. Compatible with cell phones and smartphones equipped with a micro-USB charging port.