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Altimeter Fenix 5

This morning, as I always do, I drove 22 miles to work in the North west of England. According to several websites there is a difference in altitude between my start and finish points of circa 220 feet, the altimeter on my Fenix 5 shows no difference in altitude at any time in the last 4 hours. Is there a setting that I have wrong or is it a faulty unit?

I've had the watch less than a week so haven't noticed this before, so I don't know if this is the first occasion or whether or not the unit has been showing different altitudes previously.

Any assistance would be really appreciated.
  • TL;DR version:
    Calibrate your barometric altimeter whenever you need it, or stop using it.


    So you're just saying to not worry about erratic altitude measures as long as after calibration altitude is not climbing/decreasing to some crazy values?

    My watch for last couple days stopped climbing to 20k meters and shows floor climbed correctly, but from time to time shows some crazy values.

    Serious question - what value shout I put as "sea level pressure" when I calibrate barometer?


  • So you're just saying to not worry about erratic altitude measures as long as after calibration altitude is not climbing/decreasing to some crazy values?


    Yes. Variations of up to 10-20 meter per hour or 1500 meter totally are within the expected range caused by pressure variations in the surrounding air. Such errors are not an error of the watch, neither software nor the internal pressure sensor. The errors are caused by variations in the pressure around you, and the watch is reacting correctly to those variations.

    My watch for last couple days stopped climbing to 20k meters and shows floor climbed correctly, but from time to time shows some crazy values.


    If you see 20 km altitudes (and you are not near to 20 km), it is an entirely other case. That is a malfunction which cannot be explained by variations in ambient pressure.

    Serious question - what value shout I put as "sea level pressure" when I calibrate barometer?

    My watch (Fenix 3) does not have that option. I can only calibrate the altitude, and then the watch will calculate the sea level pressure from the input altitude and the measured ambient pressure.

    Anyway, if this function works as I think, I would say "Nothing" in most cases. Inputting the sea level pressure manually only makes sense if you want to calibrate your altimeter and don't know your current altitude. If you happen to know the sea level pressure at your location right now, you can then input this to the watch, and the watch will calculate your altitude from the input sea level pressure and the measured ambient pressure. This is what a pilot in an airplane does before he lands at an airport.

  • Former Member
    0 Former Member over 7 years ago
    Hardware or software issues or a combination of them does not matter to me: surely my whatch does not comply with the product specification (i.e. very frequent macroscopic errors in altitude/ambient pressure measurement +-4000-5000m or +-400-500mbar).
    Since I am worried a new F5 will give me the same problem, does anybody know which are my option in terms of giving back the watch and have my money back? If the watch does not comply with the declared specs I do hope I have the right to go for another brand (could this depend on the purchase country legislation? mine has an Italian -EU Guarantee).
  • Today my Garmin Fenix 5 altimeter is definitely having problems ...
    Went from 65000' to -40000 ft and eventually returned to normal over a couple hour period (and once I rebooted it recovery was able to take place better ...)

    I do think there is an issue with static electricity causing the ambient pressure sensor errors - I noticed my display was corrupted a bit at the bottom and where the steps are (center close to bottom) on the stock Garmin Analog watch face. The numbers looked fuzzy and I noticed random bits at the bottom of the watch face. I went to another widget and when I returned I saw this clear up. This was happening right around the time the altimeter/barometer/temperature sensor were recovering from the crazy climbs and drops. Also each time this happened today I had just put on my winter jacket to go for a car ride - outside temps were in the 20's and low 30's today (Fahrenheit) with very low humidity and high pressure.

    BTW - My Fenix 5 was packaged in March of this year, I was told it was one of the first batches (even though I just purchased it in December 2017).

    So is there a static electricity issue here causing maybe both the display glitch and the ambient sensor glitch?
  • Where exactly do you see the manufacture date of the watch?
  • I thought my watch had settled down, but last night I apparently ran up and down a few mountains (+/- 1000m) in my sleep :(
  • Same here. Since washing mine yesterday morning, the altitude has been all over the place. Just calibrated twice and within 5 mins it's screamed up to 600 and back down to -500 again.

    Not sure if water/soap has got trapped in the hole or something else funky going on. Been so much better until this.
  • My Fenix 5 did an impression of a ballistic missile last night when I was in bed. I watched it rush up from 1200m (correct reading) to over 17500m in just a few minutes before crashing down to about 1300m. This is getting more and more annoying.
  • i beat you and reached 65k feet ;-), then dropped to -5000 and back up again. Tried drying the sensor holes with a hair dryer and since being turned off overnight it's settled pretty nicely and looking good again.

    Not great to half expect this kind of thing to happen when you wash the F5 say after a big activity or swim
  • Ok, I thought that had the problem fixed but it isn't. We have a Polar wind with low temperatures of 1ºC (don't laugh) and got several spikes in altitude.
    What solved the problem was:
    Put some water in the hole and don't calibrate the altimeter. The altitude will start to decrease.

    Personally it's not a big problem because I can live with 2 weeks/year with this problem.