"What Our Gearhead® Experts Are Saying:""Having a spare AXS eTap Battery is a must for big days or travel. It’s compact, stashes easily, and swaps out in less than a minute. If you want zero interruptions on an electronic drivetrain, always bring an extra.""With the AXS eTap Battery, missed shifts and drained rides are a thing of the past. Designed to seamlessly power any AXS eTap rear or front derailleur, this rechargeable battery charges quickly and runs up to 600 miles per cycle. The simple, tool-free removal and compact size mean carrying a backup is effortless—making sure road, gravel, and adventure builds all stay ready for action. Whether swapping between bikes or prepping for a race, the AXS eTap Battery keeps every ride smooth and reliably connected."