eTap batteries are literally a snap to remove and charge. Just flip the tool-free battery latch up and slide the battery up and out of the derailleur. Then snap the battery into the USB powered charger and connect the charger to any USB power source or A/C USB adaptor. A full charge takes just 45 minutes to complete. Easy and fast charging for your SRAM RED eTap batteries.
Includes one USB power charger/AA battery converter and one car charger, USB cord, and power tip. Put in four AA size batteries and the battery converter will convert them to 5 Volt USB power to feed the iPhone 4G and all other phones instantly. No waiting time is needed. The car charger is the one stop charging for the family while they are in the car. You can take turns refreshing your phone
SRAM Red eTap Battery Charger and Cord Gear Levers & Shifters on USA sites