Honda FourTrax Rubicon TRX520FA5 2020 Owner's Manual page 207

The battery is located in a compartment under the rear fender cover.
UNDER REAR FENDER COVER
(1) rubber band
(2) negative (–) terminal lead
(3) battery
Removal
1. Make sure the ignition switch is OFF (w).
2. Remove the seat (page 132).
3. Remove the rear fender cover (page 133).
4. Release the rings and remove the rubber band (1).
5. Disconnect the negative (–) terminal lead (2) from the battery (3)
first, then disconnect the positive (+) terminal lead (4).
6. Remove the battery taking care not to drop the terminal nuts (5).
(1)
(3) (4)
(2)
(4) positive (+) terminal lead
(5) terminal nuts
Servicing Your Honda
Battery
(5)
197