Bushnell PowerSync 8-watt-hour Battery Bar Portable Li-Ion USB Charger Compact, tough and lightweight (5.4 oz.) unit charges quickly and retains power for extended periods Easy to read on board battery level indicator 2200mAh Li-Ion battery on-board to charge your smartphones, MP3 player, E-Reader, camera, or GPS device Battery charges from a USB power source in 4-hours using included USB/Micro-USB cord Single USB output compatible with nearly any USB powered rechargeable device