SRAM eTap Battery

At SRAM, they know that if a technological advancement clutters the experience, it shouldn't be called an advancement at all. Because it's a bicycle. It's supposed to be simple. To make something elegant to the point where it removes what's in the way... that's advancement. And that is the standard SRAM held themselves to while developing their first electronic shifting system. It's called SRAM RED eTap. 

Featuring SRAM's advanced shift logic (right lever makes it harder, left lever makes it easier, both levers to change the front ring) with SRAM eTap you'll shift more, with less effort and spend less time doing it. Shifting has never been more intuitive or as easy as this. 

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. 

Compatibility: Compatible with SRAM Red eTap / eTap AXS derailleurs, only. Not compatible with products of other manufacturers.