An awesome combination of a high-density 2500mAh battery, an integrated Micro USB connector, and our Brainy Technology (for intelligent charging) in a business card-sized unit. PowerStack battery packs are so compact and light that you won’t even notice you are carrying them and will keep your Android smart phone running for hours and hours. Available in a choice of three striking colors, PowerStack battery packs are compatible with all the most popular Android smart phones from leading vendors. Their retractable Micro USB connector makes charging your device a snap by eliminating the need to carry around an additional cable. With their unique “Stack ‘n’ Charge” technology, PowerStack battery packs can be recharged “cable-free” using the PowerStack charging pad. The pad can charge up to three PowerStack battery packs at the same time, reducing clutter in the office and home. For added convenience, PowerStack battery packs also feature a micro USB port that allows charging using a USB 2.0 cable. Ultra-sleek and ultra-stylish, PowerStack battery packs provide all the power you need for recharging your Android smart phone without a single cable in sight, whenever and wherever you require it.