Li-Polymer 4000mAh capacity rechargeable battery. This slim, lightweight 4000mAh rechargeable battery is perfect for travelers to charge their mobile electronic device in any situation. The compact and stylish battery design makes it convenient to carry it in your bag or pocket. It can charge smartphones and iphones up to 2 times, or tablets up to 1 time (depending on the device battery capacity). To check the battery status, tap the battery body and 4 LED indicators will show the remaining power. This RIVAPOWER battery can be charged and discharged more than 500 times and comes with an integrated USB - micro USB cable so you will not worry about forgetting the cables. With safety protection against over-charge, over-discharge, over-current and short-circuit protection and automatic turn on/off. Compatible with all popular models of smartphones, tablets and other mobile devices. Input DC: micro USB 5.0V/1A. Output DC: USB 5.0V/2A for speed charging the mobile devices.