bKey USB Emergency Portable Battery Charger Ultra-Thin Compact 350mAh External Power Bank Backup - 45+ minutes surf talk time - Galaxy S6 S5 Note Nexus HTC- Fits On Keychain - Rubberized Matte Black To charge bKey, make sure the top cap (the round-end where the smartphone tip is located) is FULLY CLOSED. Remove the USB cap (the other rectangular end of bKey) and plug it into a USB port on your computer or AC wall adapter. The light will glow red to indicate it is charging. Once its charged completely (takes approximately 1 hour), the light will change from red to blue. Open the top cap (the round-end where the smartphone tip is located) by gently placing your fingernail underneath the latch pushing upwards on it until it opens. It will get easier to open after several uses. Wait until your phone reaches below 40% battery power and plug in your bKey to charge your phone. It can take up to 30+ minutes for bKey to empty its full charge in your phone. You must recharge your bKey again before its next use by following steps 1 to 3.