Fenix 7S Sapphire Solar Shutting Off During Outdoor Runs

You may get some suggestion on things to try here (user forum) but, given your busy race schedule, I would suggest you also call support (generally a call is faster than email).  The terminology is sometimes not consistent- have you tried a factory reset?  Anyway, support may be your best bet. 

Yes I have done a factory reset. That's is what I meant by hard reset. Sorry for the confusion.

Unfortunately, my watch is just out of warranty so Garmin support isn't an option. A $1300 watch should really last for more than a year unless there's physical damage of some sort. Very disappointing. It's not really in my budget to replace it.

Thanks for the reply and suggestion.

Garmin Support is still an option - they may have some ideas and may still consider a refurbished swap or something. They have been known to be flexible at times.  Nothing to lose.  

I somehow happened on what likely is the cause of your issue.

In short, The OS has thresholds where itll auto shut off. I dont recall exact numbers, but say its when 10min are left only. 

Well while you are using your watch during an activity, at say 30% with a battery life remaining of like 5 hours with a currently in progress activity. 

If at some point during this activity "something" happens to bump up the battery consumption, like you activating the flashlight, or some obscured system sub-process, even if that actually was only going to run for seconds consuming little battery, the OSes watch dog basically saw "BATTERY DURATION REMAINING HAS DROPPED BELOW MINIMUM THRESHOLD. TRIGGERING RESPONSE".


From other forum posts, it seems garmin has acknowledged this and going to implement a fix. This same issue triggers your "battery saving" watch face mode on your watch and ends your activity, if you had that feature enabled in some cases as well.

Certainly seems possible, but it's happening many different battery levels. Sometimes as low as 23% and as high as 37%. If it was always when the battery reached 30% or 35% that would be more likely. But since sometimes it gets down much lower, the threshold would seem to be changing.

I do hope Garmin come out with a fix, but I can't have this happening in the middle of a big race or long training run.

Thanks for the reply. I'll see if maybe Garmin have any suggestions until the fix is released.

I feel bad that i cant find the threads to link to you. But your response was echoed by others, which then were followed up with people explaining the cause that made sense to me. Maybe searching some of the terms/concepts in our convo here may lead to them? If I recall it was both here on garmins forum and on reddit I saw these discussions.


I think even in your case with 23% and 37% its got to do with things like, for certain actions can "drain" 20% per hour, but those "actions" run once every 3 hours, for a period of .01ms or something. Since the OS is closed source, we can only observe the behaviors of the system and formulate off of that.  From a batteries perspective 23 and 37 percent arent that far apart voltage wise since your battery doesnt drain to 0v, and those high power consumption nanosecond actions could knock down that voltage for enough time for the watch dog to observe the "critical" battery level. 

The interruption in activites and corrupted data is brutal. It disappointing if it happens during a live race. You lose the feedback and of course the music.

If that happens during a virtual marathon that's a qualifier, at say mile 20, it would all be for not.

I hope a solution can be found.

PINE_OS said:

I think even in your case with 23% and 37% its got to do with things like, for certain actions can "drain" 20% per hour, but those "actions" run once every 3 hours, for a period of .01ms or something. Since the OS is closed source, we can only observe the behaviors of the system and formulate off of that

I'm sorry but, with all due respect, this is pure speculation with little, if anything, to back it up.  For that matter I have seen nothing to indicate this is a commonly found issue. I can imagine what the forum would look like the day after a major marathon - nothing but "my watch rebooted during my race".!  I can't count the number of times I have been out well over 3 hrs and ended with a battery level of 10% or less.  G514 - call support.  Who knows, maybe I'm wrong and they will acknowledge the issue.

I plan to call them as soon as I get back to my hotel, or if they're closed by then, first thing in the morning.

As you said it can't hurt. f they can offer any solution that's better than buying a new waych it will be progress. It's not like I have $1300 sitting around. And to make matters worse it would be for the exact same model since they haven't released a Fenix 8. A top end watch should last at least 2 years until they release a newer model, or longer.

As you said it can't hurt. 

Did you... find the threads I was trying to find to give you confidence in your very convicted position? I suppose I just want to understand why you are so confident this CANNOT be possible. 

Battery watchdogs do have wacky behaviors like this. Have you had any exp with embedded systems or similar platforms?