The discreet LED light glows softly to let you know at a glance that the unit is powered. Even if you're not near a wall or car charger, you can recharge your device's battery with the convenient battery pack. The intelligent battery pack supplies power first, so you can remove the pack after use and still have a full battery on your device. 3 USB ports to charge three devices simultaneously. Smart protection against overheating, overvoltage and overcurrent.