Keep your USB-powered devices charged while you're on the go with the Aluratek APB04F dual USB 8000mAh portable battery pack. This handy backup battery uses the most up-to-date Li-Ion technology for fast, superior charging, and the rapid charging feature lets you charge your devices faster than via a traditional AC wall outlet. The built-in LED indicator lights let you know how much battery power you have left, so you'll never have to guess when to recharge the battery pack.