What type of batteries do the Eagle AXS controller require? One CR2032 watch battery - commonly found at retail outlets. The lifespan of this battery is significant - 2 years or more is common. Related articles Are SRAM AXS controller (shifter) batteries replaceable? How do I check the battery levels of my AXS components? How do I know if my Eagle AXS battery is low? What are the charge levels and how many hours of riding can I expect to get on a full charge? How should I store my AXS equipped bike and derailleur batteries during the off-season or when the bike is not in use for 2-3 months or more? Do I need to do anything different when washing a bike with SRAM RED eTap?