How to repair your Garmin Forerunner 305

Garmin forerunner 305 cut open

I own a Garmin Forerunner 305 for many years now. Many times I considered buying a new one. For triathletes like myself the Garmin 920XT is the reference at this moment.
You can call me nostalgic or penurious, but I am still hanging on to the Garmin Forerunner 305 For the stuff I do I need 10 hours+ battery life. That is a challenge for most GPS watches. When the Garmin Forerunner 305 was brand new it would just do the trick. At some point after 3 years or so of usage it didn’t last longer then 1,5hour on a fully charged battery. No more feedback during the ride and very bad for my training and race log. Other then that the forerunner was working fine. So I needed to increase the battery life again. After a bit of google I found a movie explaining how to do it. So I bought myself an ipod mini replacement battery and went for it. I had nothing to loose. The forerunner had become useless anyway. Should I fail and break the forerunner completely my loss would be the purchase of the battery. Should I succeed I would have increased the life-cycle of my forerunner by a few years.
Garmin Forerunner without battery
Repairing stuff is very trendy. Amsterdam was the first city where there was a repair cafe, a meet-up of people to repair appliances/devices with the objective to reduce the waste pile.

I simply followed the video. Some points of attention. I glued the watch back together with the same glue which is used for PVC rain gutter pipes. That works fine. When putting the watch back together make sure the print on one side is connected with the buttons. This is also important for the GPS antenna. I have been using it for quite a while now without any problems. The battery life went up to 10hours again after repair and is now decreasing again. I will have to replace it some day anyway 🙂

Master reset of your Garmin Forerunner.

Sometimes the Garmin may lock. It wil not switch on for example. What you should do in this case is press the “mode” button” and the “enter” button at the same time. Then hit the power switch while keeping the other two engaged. Release power and continue pressing mode and enter for 10 seconds. Release and your Garmin will switch back on. You data will not be wiped.