Fenix 5S Plus sudden increase in battery drain

My ~3yo Fenix 5S Plus suddenly started draining battery much quicker than before (100% to zero in 24h with no activity and all sensors off). I used to be able to go for a week without charging. I cannot tell what triggered the change, if anything at all. I have already tried (to no avail) all the possible factory reset procedures, including the one triggered by pressing all the 4 buttons. Now the watch is on factory settings, except that I disabled everything obvious that could drain battery (HR monitor, bluetooth, wifi, activity tracking).
The only possible remaining lead to an explanation is that in the "Debug" folder of the watch (which apparently survives factory resets), the file ERR_LOG.BAK contains an entry timestamped 7 Jan 2023 (see below) which may be exactly when the issue first appeared. This is the entry:

2900 (fenix 5S Plus) SW ver: 1800
Build Type: RELEASE
ESN: 3977555971
01/07/23 22:39:37
PWR RST CTRL: 0x00000082

Does anyone know how I can access someone able to read what this might mean? I'd love to know whether this may be a clue to the cause of my battery drain problem. Perhaps the watch is gone, but at least if I could tell what behavior or event triggered the problem, I can avoid it in the future. Thanks in advance!

  • I am sorry there is an issue. We will not be able to interpret your Debug folder information but there are steps you can try to resolve the issue.

    Please try the following:

    - Soft Reset: Hold down your top left button until your watch shuts off then let go of the button.

    - Default Settings Reset: How to Reset Default Settings on My Garmin Outdoor Watch

    If you continue to have an issue, please reach out to Outdoor Product Support in your region.

  • I have already tried every available option, including the Garmin Support chat, and as I wrote above, "all the possible factory reset procedures, including the one triggered by pressing all the 4 buttons." This means soft resets and all the three types of factory resets suggested in the Garmin guidance article quoted in the reply. At this point I was just trying to understand what may have caused this behavior, and as I wrote, the only possible remaining clue is that entry in the error log.

  • I am sorry we won't have any further information. My sincere apologies your watch has an issue.

  • Hello! I have the same problem (I described it on Reddit: hwww.reddit.com/.../ ).

    I'm going to try to search the debug folder and look into it. Also, I want to change the firmware (battery was replaced by me, but still with the same problems).

    I'll keep you updated.

  • Yesterday, I did a hard reset again.

    Debug folder:

    2900 (fenix 5 Plus) SW ver: 1800
    Build Type: RELEASE
    ESN: 3300479198
    01/22/23 00:45:15
    PWR RST CTRL: 0x00000082

    Sensor Hub Reset, v240

    Reset loop count: 1

    Errors start (more or less) on Nov 16, 2022.

  • Version 19 does not fix the problem. I returned back to ver 18.

    At this moment, battery drops 2.1% every hour = 50% every day.

  • At this moment, we can reduce the possibilities to:

    1. Battery is not charged completely for some reason (I noticed that the charge time is faster now) although the indicator is 100%

    2. Watch is consuming more power than before.

    After changing battery and hard reset, I don't understand why.

    Next steps:

    - Check if battery is being charged fully.

    - Measure how many power is consumed by the watch.

  • I have swapped my battery, it's better but no way near before. I used to be able to get 8-10 days. Then at the end of the year it dropped overnight to 4 days, so around 25% a day. I didn't want to pay the silly fee Garmin were quoted so swapped the battery myself. The new one new uses around 21% a day. I feel there is a software issue causing this. I was considering stepping back firmware versions to try and ascertain when this happened. The lack of support from Garmin speaks volumes... as if they are happy this age of watch is failing!

    How can we join together to sort this? It's not that I can't afford a new watch but I feel lots of people experienced the same thing. Could something have stepped forward in the firmware update that can't be reversed? Like the amount the BT pings, or HR sensor flashes per min that reduces the battery length?

    How comes this only seems to impact the Fenix 5?

  • I considered the battery not charging for the correct duration so plugged mine in, when it reached 100% I left it for an additional two hours... made no difference

  • It seems that the charge time has decreased also...

    So, I think that we should make a document with a procedure and then, measure all the things that we can, in order to do the research reproducible, repeatable and replicable.

    So, we can start turning off all the integrated sensors (HR, BT, etc and then, measure). I'm going to create a document (draft version).

    It's not a question of money, I just find out why Garmin does nothing.