I recently received a “Low internal clock battery” alert on my GTN-635. As I understand it, this can cause the GTN to take much longer to acquire it’s location, and this indeed seemed to be the case.
The Garmin uses a 14250 battery, not something I could easily find locally, but Amazon had next day delivery.
After removing the GTN, you’ll find 6 Phillips screws on top. All of the them are the same length except for a short one in the middle location on the right side.
The battery holder is right in the middle of the board and you’ll need a tiny flat-head screwdriver to pry up the catches on each end. After that, it’s a quick swap and everything can go back together.
