GPS distance totally wrong on Charge 3

[BertilDator]

Was doing cross country skiing, and set activity to "run" (as there is very limited activity list). Had phone connected, and got perfect GPS route on Fitbit activity. However, all the splits are way off. Total distance in Fitbit shows 4.8km while real distance was 7.5 km (I know the route, and even double checked via ontegomap.com).

How can Fitbit calculate distance so wrongly even though the GPS route is perfect on the activity? I repeat, the tracked route is 100% correct on the Fitbit activity in question, so there is no disconnections, or trees, or anything between the phone and GPS satellite, nor between phone and Charge 3.

Is Fitbit using GPS route for distance calculation when assisted GPS is enabled during "Run" activity, or does it STILL use stride length?

Should I use "Biking" activity for XC skiing to get accurate distance based on the GPS route?

[RobaJett]

I searched this issue as I'm experiencing it myself out of the blue (regular 5.5k just had an epiphany and decided it was a regular 4.2k). 

Just wanted to thank everyone for their updates and impromptu field tests.

The TL:DR seems to be;

- data reads correctly when observed in isolation of the tracker itself.

- tracked GPS data appears to only be for the pretty map picture at the end of the workout.

- workout itself seems to only be calculated by stride length, which is currently on the fritz

- Fitbit are aware and have been looking to resolve the issue for some weeks now.

- Fitbit users are all checking Garmin prices and using Strava to track their runs.

Shout out if I've got any of the above wrong.

[t.parker]

@RobaJett you have got one thing slightly wrong. Fitbit is aware of the issue but probably isn't looking into it at all as it isn't an issue but design. This is how the distance calculation has been designed to work.

[socal13]

RobaJett - seems like your summary is correct, except possibly for the point about "Fitbit are aware and have been looking to resolve the issue.."  I haven't seen any evidence of that.  In fact, my experience with Fitbit support indicates that they have no clue how the device works and don't really understand the concept of GPS distance.  I was told by support that GPS distance was dependent on my entering the correct stride length and weight, which of course should be immaterial to GPS distance.  The support person surprisingly disagreed.

I've only been involved with this issue for a few days - I'd greatly appreciate it if you can point me to a response from Fitbit indicating they are actually trying to correct their GPS issue.  It might even encourage me to keep the device rather than returning it.

Thanks for your post!

[RobaJett]

@t.parker @socal13 

I'll update my post to inject sarcasm to the "Fitbit are aware" comment - as my evidence of such is second hand. Cheers for the callout.

Please see below the response one user on this thread had from Fitbit support (page 8 of 10).

 

[socal13]

Thanks, robaJett.

The GPS problem with the C3 is even more basic than I thought.  It fails to record correct distance in "bicycle" exercise mode as well, where stride and steps are not even a consideration.  My wife and I took a ride today to the beach - we each have a C3 and Samsung S9 phones.  We started the bike exercise precisely at the same time, rode side by side all the way, and looked at the distance upon reaching the beach.  Mine read 6.9 miles, hers read 6.1 miles.  That's a 13% difference!  It obviously, then, makes the speed calculation incorrect as well.  At least the time was recorded accurately on both.

Fitbit has a basic issue with GPS on this device.

[ikinga]

I tracked several runs (10+) with Charge 3 connected to the phone + using another app, for my last few runs I used Strava. Fitbit is always off, showing less distance, so is the pace of the running. I would like Strava to analyse my heart beat, but I don’t know how to keep Strava’s GPS track and match the registered Fitbit HeartRate. At this point, my Fitbit is becoming useless... Looking for other options. After 5 years with Fitbit I am very disappointed. 

[ikinga]

I have same issue on iPhone X. My Fitbit is always a bit off, showing 5% or so less distance. 

[Procter101]

Hopefully final update.

Fitbit have agreed a replacement after 2 months of emails and a 14 day deadline before legal action given

Support number is from UK 0800 069 8505.

Good luck to you all and hope I do not need your help or support again

[socal13]

Thanks for the update, Procter101.  Are you replacing it with the same model, or getting a different model?  I've assumed with my Charge 3 that the GPS issue is a design problem, where replacing it with the same model would likely yield the same problems.

[Procter101]

Replacing with same model as I certainly do not wish to take them up on
their 50% offer on other models. I have no desire to give them more money
If the replacement does not work I will go down replacement route until
they offer a charge 4.
Jepp banging on.

[ukAdamR]

I concur entirely Procter101. Having only just upgraded to a Charge 3 earlier this year it would be an insult for it to already not work only to be offered a discount for an upgrade. If the existing product doesn't work as described and requires an upgrade the customer cannot be responsible for the cost of that.

I've filed a support email too. My walking distances are still inaccurate af, which defeats the whole point of a fitness tracker. I'd suggest anyone else writing in here do the same. Make some noise on the issue.

[socal13]

Good luck with your new device! 

Please let us know whether your new C3 works correctly, or whether it also has GPS issues.

Thanks!

[Procter101]

Thanks for your good wishes.
I will certainly be back on if it does not work

[Springy.BitFit]

I don't understand why would a new device fix the issue?

I usually get Strava to correct my GPS data, so for me it is a non issue so can live with it.

Since I got my fitbit c3 it always had incorrect distance, sometimes it too long, sometimes its too short.

I don't understand why fitbit uses steps length to determine distance.

Anyway it is software issue, they need to update all their device that if they have GPS either on device or connected that they should use it as the primary way to measure distance.

[Procter101]

I agree but having received a new device I will be checking and if it does
not work will require money back. The flights of stairs is just as annoying
as I live in a bungalow!!???

[Springy.BitFit]

Yeah that is weird, when I go for runs it thinks i am going up stairs. I think it is looking at small elevation gains, but again not too worried about that. Its all software... Wonder if Google would make a difference whenever the take over happens.

[socal13]

Please let us know, Procter101, if your new device works any differently than your old one.  I checked our devices again yesterday, using the bike exercise with GPS (supposedly).  My wife and I took a very short bike ride together, on the exact same route, and one Fitbit registered 3.2 miles and the other 2.5 miles (28% different).  Terrible.  I called Fitbit, again, and this time asked to escalate to the next level service rep.  It was a totally useless conversation, as the rep really didn't seem to have any idea how the device actually works.  She said it must be my phone that is having the problem.  When I told her that both of our devices seem to generate random distances, every time we use them, she insisted it was my problem.  I referred her to this forum, where many users see that the GPS doesn't work properly and she dismissed it as phone problems.  She offered to send replacement Charge 3's, but this seems a waste of time if it is a design issue, which I'm pretty convinced it is.  

At any rate, I'll be interested to see if another device works any differently for you.  Thanks,

[t.parker]

@socal13 simple question: is the map registered by your device and your wife's correct and the same on both devices (when you look at it from web dashboard or from within the app)? If so then GPS worked correctly and you should state it to the customer support. Additionally, you may export TCX files from both rides and upload them to https://www.mygpsfiles.com/app/. If the distances for both rides will be the same (or very close to being the same as GPS isn't ever 100% accurate) and close to the real expected distance then you have another argument to deal with the customer support - GPS map is correct and the distance of the GPS track is correct, too.

[Procter101]

Just got replacement but seems to have same problem.
Rode 26 miles at 12. 2 mph. Walked approx 500 yards maximum i.e called at 2
shops.
Fitbit says
9735 steps
4.67 miles
41 flights of stairs
96 minutes of activity vs actually probably 140 minutes. Will collate a few
more days and we will start again

[socal13]

Thanks, t.parker.  Yes, the maps shown on each respective app are the same for both charge3 devices.  And, after downloading the tcx files to mygpsfiles.com for both devices, the GPS distance is exactly the same for both devices as well - 2.7 miles. But, on my fitbit charge3 app it says 2.4 miles, and on my wife's fitbit charge3 app it says 3.2 miles, not even close.  So, the GPS data is being gathered correctly from our phones, but the fitbit devices (or app) are messing up the distance calculation.  Seems like this should be simple to fix.  Not sure why they haven't, and why they won't admit to the problem; it would be very simple for fitbit to recreate.