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Is the altimeter reliable on any of the forerunners - 935/945/Fenix?

KR17
over 5 years ago

Hi,

I'm on my 3rd 935 now. Previous ones all had altimeter failures eventually.

Have Garmin got this issue fixed on any of the watches? Did the same design carry over to the 945 or is that one reliable? What about the Fenix - is that reliable or does that also fail?

To clarify, by fail, it starts off OK. But after a few months I just get constantly varying readings that make no sense over very short periods. If I sit the watch in one place it is climbing or descending rapidly. The elevation on my activities show no relevence to reality (climbing hundreds of feet in the first 15 mins of an activity even though I'm going downhill), and also the random popping up of stairs climbed even though I'm on the flat.

I am aware of how barametric pressure etc works. I'm NOT complaining that its telling me I'm at different heights on different days. I'm referring to the short term change in altitude being a mess. The watch always works perfectly when I change it, so I know its not me or my expectations.

So, what are my options. The 935 altimeter is simply not fit for purpose. Is it any better on the 945? From a quick read it would appear its the same design and same problems. What about the latest Fenix? Is it fixed or changed on those?

Thanks in advance.

  • 0 over 5 years ago in reply to KR17

    FWIW I have the alitimeter set to auto-calibrate continuously during activities  and on, not during activity. The Barometer Watch Mode is set to auto.

    I do see small differences between the end points on loop runs/cycles but nothing to write home about. I am only interested in the elevation gain/descent for an activity and not too fussed about the start altitude. But then I am broadly at sea level.

  • 0 over 5 years ago in reply to Dr Phil

    That's a 10% difference, I wouldn't say that is negligible.

    For comparison, I have an original Fenix that I used previously and it was almost always spot-on with starting/end points and less than 2% difference on elevation gain/loss for out and back runs.

    I also use a Lezyne bike computer when I cycle with my 945 and it very consistent with regard to the above as well.  Like I said in my original post though, I am "okay" with this but I wouldn't call it "good."

  • 0 over 5 years ago in reply to badbri

    the original fenix was probably spot on because the barometric altimeter was constantly calibrated with GPS values. This functionality was abandoned and never seen again in a Garmin watch. Suunto still has it, its called "FusedAlti".
    The FR 945 has apparently the option to use the map relief data to do continous calibration. But i cannot see any improvements (vs FR 935). I would expect start and endpoint to be on identical altitude if its a loop.

    How i deal with it: When in the mountains, i always have a data field which shows the GPS altitude so i compare both values (GPS and barometric). 

  • 0 over 5 years ago in reply to Heikoo
    Heikoo said:
    How i deal with it: When in the mountains, i always have a data field which shows the GPS altitude so i compare both values (GPS and barometric).

    That's a neat idea.  I do a bunch of mountain runs so I will remember that.  I'm at only 200-400' ASL for my home base though so it doesn't really matter too much.