My excellent Garmin GPS V after 10 years of service needs small reparation. The problem was the navigation lost almanach of satellites after battery replacement. After turning on it needs 5 minutes to find the satellites. Reason for this was an old backup "battery". It isn't really a rechargeable battery, but an electric double layer capacitor Elna Dynacap 3.3V 0.22F.
To open the device it is necessary to remove six screws. Because this unit is supposed to be waterproof, it is necessary to pay attenion to the rubber insulation.
Garmin GPS V inside:
It is difficult to find the original double layer capacitor. So I decide for a different one, which has similar parameters.
New supercapacitor with higher voltage (5.5 V) and the same capacity (0.22F) is much bigger in comparison with the original Elna 3.3V So I must re-locate the capacitor. New place was found in the back cover, around battery compartment. Capacitor is fixed using double sided tape.
GPS is now working as it used to when it was brand new.