Connected GPS Pace and Distance is Inaccurate

[DanielMena9]

Went on a run today with my Charge 2 on one wrist and Charge HR on my other wrist. Also had RunKeeper to measure my distance. I started my run with about the same number of steps on both FIT devices. 

After the run, my Charge HR had almost 2K more steps than my Charge 2. In addition, my GPS map on FitBit matched my Runkeeper map which is about a 3.5 mile run BUT FitBit pegged the same route as 1.73 miles >.> 

Why doesn't this device work as advertised? I really like the design and feel of Charge 2 but if it can't do its job accurately, all is for not and I will be shorting FIT as it appears to be a widespread issue (I have maps and photos if someone from FIT wants the data).

Moderator Edit: Edited thread title.

[Bibster]

I think you're right on the solid phone icon point.

FitBit have posted advice previously (possibly on this thread) regarding the importance of a good Bluetooth AND web connection at the start. I have done this for a few weeks and had good results. I cycle from home to work with good WiFi or 4g so can do this, but it's not practical advice for someone on a run in the countryside!

So I think that's the possible weakness of a Charge 2 versus a Charge HR. I think an HR just needed Bluetooth, not internet, and could sync HR data later once internet was restored. I think the reason the Charge 2 may need to keep talking to the App and FitBit.com whilst you run or cycle is for in the in run/cycle stats on the tracker (speed etc.) which I never actually have time to look at!

So FiBit could have (needlessly in my opinion) configured things in such a way that the GPS accuracy relies on good internet from the start and during exercise, instead of just Bluetooth. If they fix this issue, they take away a feature they have actively actively promoted (stats whilst you run).

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[Glennbest]

I get 10% or more inaccuracy whilst your tests are showing about 1%. I'll try your suggestions and see how I go.

Thanks bobby

[hawkeye1952]

Here my results for today. I had the phone and fitbit on the same side. I walk 1.05 miles and fitbit showed 1.00 miles.

[bobby2478]

Bibster charge hr didn't have connected GPS, Bluetooth was only to sync steps with the app.  Charge 2 has Connected GPS which is where the inaccuracies are.  That's why I tested 3 ways,  with non connected GPS device (hr), connected GPS device (charge 2), and with no tracker at all (just mobile phone and app). 

Glennbest Yeah next time you try before going out try to make sure that you open the Fitbit app first so it's in the foreground and you get the solid phone icon on the Charge 2, those are the things I did that I read fitbit post to help with connectivity 

[Annabel_b]

bobby2478, are you using automatic stride length on your account or have you set it manually?

[bobby2478]

Auto stride length, but with connected GPS that shouldn't matter after their first firmware update on the Charge 2 fixed that part.  It's still in accurate but better than it was 

[Bibster]

Hi Bobby,

Later versions of the Charge HR have connected GPS, earlier models did not.


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[bobby2478]

Bibster I'm sorry to inform you but you are incorrect.  No Charge HR has Connected GPS.  This is what enables you to be able to start manually recording exercise from the tracker itself instead of on the Fitbit app.  With Charge HR the exercise and distance is captured by the mobile app and the only thing the Charge HR does is capture heart rate and floors climbed. 

Charge 2 on the other hand is not another Charge HR, it's a completely different device and the sequel to the HR.  Thus Charge 2 has Connected GPS functionality, where the HR does not. 

[Bibster]

Bobby,

Sorry let me rephrase, I don't mean "Connected GPS" which is no doubt a term patented by FitBit. I mean connect to your phone's GPS: you could use your phone's GPS and your HR's heart rate data and they would connect via the app.

My point is, the input and output is basically the same. Both devices (HR and 2) lack their own GPS and require you to take your phone for GPS, yet the HR was more accurate at measuring distance via your phone.

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[bobby2478]

Only thing is with the Charge HR, data only really goes from the band to your phone.  GPS data from your phone doesn't need to sync back to your Charge HR.  So syncs one way basically. 

With the Charge 2 and any Connected GPS, GPS data does sync to your actual Charge 2 so data syncs both ways.  So your Charge 2 uses your phones GPS signal.  The Charge HR doesn't. 

Just wanted to clarify because the reason the Charge HR works well is because it doesn't do anything with GPS.  It's all handled by the app.  With Connected GPS this is no longer true and distance gets wonky. 

[hawkeye1952]

bobby2478 (Base Runner) No it is not. I have found even with the lastest update. That there is still wide swing in readings. I use 2 other apps and have compared them. I have found that the most it as been is .01. When useing the fitbit connected gps. I have found the difference as mucu as.10. There is a major issue with the connected gps.

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[Annabel_b]

Agreed. For now I am going to keep my Charge 2 and go back to using the Mobile Run feature in the iPhone app to track my runs. I find it reasonably accurate (as long as I calibrate my stride length) and there are a lot of things about the Charge 2 that I really like. The only feature I lose is not being able to check my pace on the Charge 2 in real time but I can get that from audio prompts from the app instead. I hope that Fitbit will come up with a fix eventually; it's ridiculous that connected GPS is so, so wrong (I tested it again today and it was 19% out!).

[bobby2478]

 I just performed another test, detailed below.  Both exercises were recorded at exactly the same time (carried 2 phones with me) and were both started and stopped at the same spot :

Test 1:

Manually recorded walk exercise through fitbit app on a Samsung Galaxy s4 with no tracker connected. 

Total Distance: 4.60 miles 

Test 2:

Manually recorded walk exercise from Charge 2 via Connected GPS synced with Samsung Galaxy Note5. 

Total Distance : 4.68 miles 

So off by 0.08 miles, in other words it overstated distance by about 1.75 %. 

[hawkeye1952]

I done 2 test in the last 4 days. Wenesday I started the program that I use on my phone first. When it connecets to the GPS signal it tell me go. Then I started the charge2 in the walk mode. On the top right hand corner is a little bar that goes back and forth and then when connect it disappears. I started and stop at the same place. On Wenesday it was of by.10  miles. Did the same thing to day. The only diffence is that I had my phone program in fitness walking and fitbit in walking mode. today it was of by.01. This much is for sure. When this charge2 bites the dust. I will not buy another one.

[Glennbest]

Thanks bobby. I'm starting to think that outside of the USA the connected GPS is useless. I'd love that sort of accuracy in OZ. No answer from Fitbit yet, I think it's gone into the too hard or not worth fixing basket.

[Colinm39]

@GlennbestHi Glenn.. Did you have any luck with our ACCC. ?

I have a closed case with Fitbit Blazes on the under reporting of distance by about 20% for domestic use. No solution. On a planned walk at exercise speed the distance isn't too bad.

Support had me changing stride length, setting to auto stride and using Connected GPS. Hence the images below. No solution, it is with the Engineers......

I have multiple Trackers and in the tests it was my Blaze 1 and the 2 x Surges.  For domestic walks, all of my trackers, which includes the earlier Charges are accurate for distance because it definitely multiplies steps x stride as defined. (ignoring missing steps). But the Blaze seems to invoke the 3D accelerometer and I was wondering how your domestic use of the Charge 2 goes.  Domestic, meaning home, shopping, malls, car parks etc.. No GPS....Because a step is a step...

The GPS varied on the Surges but the Blaze was about 12% over. I hadn't used the 2nd Blaze in this test.  The 2nd image shows a Google Earth plot of the same track and I had also confirmed it with MapMyRun.

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@Glennbest wrote:
From all the reports here it's clear the charge 2 is defective and Fitbit's only response is to request users send info and have patience, but fail to fix the problem whilst continuing to sell the product and provide no advice as to when it will be fixed. I've reported the issue to the ACCC as Fitbit are breaching Australian consumer law by not repairing, replacing or refunding. I suggest any other Australian customers experience the same problems to do the same.

[Rich_Laue]

@bobby2478, i think your confusing percenrage for multiplecation.

1.7 % = being of by a factor of 0.017.  So 4.68 is only 1.017 times greater than 1.60, a difference of 8 hundreds of a mile.

GPS requires a straight unimpeded line to the satellites, cloud trees and tye size of the antenna,and signal streangth can affect the readings.

Where you using the same phone model? You say you used 2 phones.

Have you done this test more than once for the same route?

You also definitely want to switch phones, so the Charge2 is tracking through the other phone.

It looks as if you are using 2 different accounts. Are your stats setup tye same? How close are your counted steps by the Charge 2 compare with the calculated steos by the app?

[bobby2478]

Rich

0.08 / 4.60 = 0.01739 x 100 = 1.739%. I rounded up to 1.75%.

Im aware of how GPS works and it's limitations.  Yes I used 2 separate phones, on 2 separate accounts, the Samsung Galaxy s4 and Samsung Galaxy Note5.  I did a test that was reported several pages ago where I took both phones on a 3 mile walk and didn't use a tracker to compare accuracy of GPS between the two phones, it was within 0.01 miles if I'm not mistaken. Both were manually recorded through fitbit app using phones GPS (not calculating based on stride length). 

So I already did that baseline comparison to verify the difference in GPS distance calculated by each phone and that accounted for 0.01 / 3.27 miles = 0.00305 x 100 = 0.31%.

Now the comparisons are between the s4 with no tracker manually recording walk through fitbit app using GPS (no tracker so no Connected GPS, which is the source of the discrepancy) and the Note5 with the Charge 2 manually recording walk on Charge 2 using Connected GPS feature to illustrate the difference in distance. 

[bobby2478]

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@Glennbest wrote:
Thanks bobby. I'm starting to think that outside of the USA the connected GPS is useless. I'd love that sort of accuracy in OZ. No answer from Fitbit yet, I think it's gone into the too hard or not worth fixing basket.

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Glenn that's certainly possible.   Only thing I can suggest is to have the app open, refresh so it syncs with the Charge 2, then with app still open and screen on start recording on the Charge 2 verifying you get the solid phone icon so you know it connected with your phone and picks up the phones GPS signal.  Outside of that then most likely it could be GPS signal strength in your area.  An easy way to test is to just take your phone (no tracker)  for 2 runs on exact same route and manually start and stop recording exercise through the Fitbit app.  This will only use phones GPS (takes connected GPS out of the equation)  in order to establish a baseline.  Both runs/walks should be nearly identical if not exactly identical.  If this is drastically different it could be your phones GPS strength. 

If it's nearly identical then any difference above this using charge 2 is solely due to Connected GPS. 

[Kenny54]

Can anyone tell me if the Fitbit team are looking into the Connected GPS issue as I purchesed my Charge 2 in January and am very dissattisfied with it. I use a Samsung 7 phone and as I told the Fitbit help it provided a very satisfactory trail map but the Charge 2 contains too many straigh lines and sharp corners. The attached photo shows the Charge 2 route in orange with another products blue track superimposed. I have no issue with the blue track as it leaves no doubt as to the route I took.