SRAMs eTAP or AXS systems are energy bundles. Their batteries are lightweight, quick to charge, removable and attached to the front derailleur and rear derailleur. Without cables, the assembly becomes child's play. eTap / AXS batteries can be removed literally with a click. Open the lock without tools, slide the battery up and out of the rear derailleur or front derailleur and insert it into the USB charger. You can connect the charger to any USB-enabled power source or connect to the mains with an A/C USB adapter. Charging time is only 45 minutes.