The GPSMAP® 66s/st handheld device operates using two AA batteries (not included). Use NiMH or lithium batteries for best results.
NOTE: The GPSMAP 66sr is not compatible with AA batteries.
- Turn the D-ring counter-clockwise, and pull up to remove the cover.
Insert two AA batteries, observing polarity.
- Replace the battery cover, and turn the D-ring clockwise.