Amazon.com: NewPower99 Battery Replacement Kit for Garmin Edge 520 Plus with Installation Video, Tools, and Extended Life Battery : Electronics
Amazon.com: Gomadic Portable AA Battery Pack Designed for The Garmin Edge 520 - Powered by 4 X AA Batteries to Provide Emergency Charge. Built Using TipExchange Technology : Electronics
Original Replacement Battery 700mah 361-00043-00 For Garmin Edge 820 Edge 520 Edge 520 Plus 500 200 205 Cycling Computer Battery - Mobile Phone Batteries - AliExpress
Edge 520 - Replacing the Speed Sensor or Cadence Sensor Battery