Garmin GPS 150 Pilot's Manual page 80

APPENDIX B
GPS 150 Maintenance
70
The GPS 150 is built to exacting standards and does not require user
maintenance. Should the faceplate and lens require cleaning, use a soft cloth and
non-abrasive cleaner.
The user data is maintained by an internal battery with a projected life of 3 to 5
years. If the GPS 150 detects a low memory battery, you will be informed with the
message 'Memory battery low'. Failure to have the battery replace may result in loss
of data each time you turn your unit off. This will GREATLY increase satellite acquisi-
tion time and no user data will be saved. This condition will be accompanied by the
message 'Stored data lost'.
The GPS 150 contains a crystal oscillator, which may drift after many years of
operation. If the unit detects excessive oscillator drift, you will be informed with the
message 'Osc needs adjustment'. When this occurs, contact an authorized GARMIN
service center for service. Failure to do so may result in severely degraded
acquisition performance.
Maintenance