Honda TRX500FGA Owner's Manual page 230

6. Charge the battery (see following section), unless you have been
riding regularly.
7. Store your battery in an easy-to-reach location off the floor, in an area
protected from freezing temperature and direct sunlight.
8. Clean the battery box after removing the battery for storage. Dry the
battery box and, if paint is missing, re-paint the area.
9. Slow charge the battery (see following section) once every 30 days.
Installation
1. Reinstall in the reverse order of removal.
Be sure to connect the positive ( ) terminal first, then the negative
( ) terminal.
2. Make sure all bolts and other fasteners are secure.
Battery
Servicing Your Honda 221