I own and carry one for about 8 years now. It is on my zipper pull and went through the washing machine several times. It still is functional without any maintenance whatsoever.
Several others I bought at the same time work just fine too.
The compass can be remagnetized (watch polarity).
Dry button compasses may collect dirt in the bearing of the needle and quit working because of that. The needle is very short and canīt override too much frictional torque.
_________________________
If it isnīt broken, it doesnīt have enough features yet.