Downgrade of Fenix 5 Plus ANT/BLE/BT firmware

Since I also experience massive battery drain on my Fenix 5 Plus since quite some time I thought I will give it a shot and downgrade the ANT/BLE/BT firmware to 6.09. I read that it solved the battery drain problem for other users. I downloaded the file GUP3153.GCD from here:
https://www8.garmin.com/support/download_details.jsp?id=15292
and placed it in the folder GARMIN\RemoteSW. After unmounting and unplugging the watch, the watch loads as usual (no sign of updating anything). When checking the firmware version in the watch, it still states 6.11. When connecting the watch to the PC again, the file GUP3153.GCD is gone.

Anything I am doing wrong?

0 -- over 3 years ago

I'm not sure what procedure others followed to downgrade to ANT/BLE/BT 6.09, anyone care to share this?

In my experience it isn't always possible to downgrade one subsystem without downgrading to the firmware package that has this subsystem version included.

You may have better luck finding a complete FW from around the time that a release containing ANT/BLE/BT 6.09 went live. I don't know which version that was. Beta 12.71 had 6.06 and beta 13.74 had 6.11.

0 ronand over 3 years ago

I don't believe there are any power drain issues with the latest ANT/BLE/BT firmware and downgrading it is not likely to solve anything. Its is possible to do it but you need the correct version (I did it before but can't remember where I got it from). You are better off factory resetting the watch and not installing any watch faces etc which may be draining power. Also its possible you battery if failing. What sort of battery life are you getting?