Charge 5 swim lap count is inaccurate after changing pool length

[AndrewGe]

We recently changed pools from 25m to 91m (100 yards).  Initially I forgot to change the pool length on the fitbit but did so on the second visit.  On both occasions it recorded wildly inaccurate results.   

Setting on 25m.

Actual number of laps 12 (12 x 91 = 1092m)  Fitbit recorded 24 x 25 = 600m

Setting on 91m

Actual number of laps 22 (22 x 91 = 2002m).  Fitbit recorded 42 x 91 = 3822m. 

I can understand that there may have been a conflict before I changed the lap length setting, but would have expected it to be accurate after the change.  

Previously, in the 25m pool it was always accurate.  

The same thing happened to my wife's Charge 5.  My Charge 5 has frozen and now has to be replaced, so I will have to wait and see if this anomaly is repeated on the new hardware. 

Has anyone had any similar issues when changing pool lengths?  

Thanks in advance 

Andy

Moderator edit: format

[DavideFitbit]

Hi, welcome to the Fitbit Community forums, @AndrewGe. 

Thank you for sharing all these details about the inconvenience you've been having with your Charge 5 and for confirming that you already tried a few troubleshooting steps. 

Keep in mind there are a few reasons that can cause inconsistencies with your swim data:  

• You completed only a few laps
• You stopped to rest multiple times or in the middle of the pool
• You stopped to rest for longer than 60 seconds after completing a pool length
• You changed your stroke type midway through a length
• You swam with a kickboard or without using your arms
• You swam less than the minimum duration needed for your swim to be automatically recognized

In addition to the reasons mentioned earlier, and if you already checked the pool length is accurate in the Fitbit app, please try to complete a restart procedure using the charging cable and check if you continue to experience the same behavior. 

I've been informed that you have indeed contacted the Customer Support team for further assistance with this. In this case, they will let you know how to proceed. Let me know if you continue to have the same issue with the replacement device. 

[AndrewGe]

Grazie mille Davide. 

I have received my replacement Charge 5 and checked the settings and made sure that none of your listed potential reasons applied.   Unfortunately the issue persists; the count of laps is doubled. 

I reset the device both via tapping the Settings and by the USB cable reset.   The issue persists.

I have used the "Exercise/Swim/Start/Finish" function.   (Incidentally, my wife's Charge 5 has a similar issue, but I think it is x3 instead of x2 but I don't have the exact details at the moment, and she has not been setting the Exercise/Swim function - just swim and let it start counting.) 

This is really weird as in the 25m pool when I checked the Charge 5 against the pool supplied "SwimTag" they were identical.  I am yet to go back into the 25m pool, resetting the setting distance, to see if it works correctly as before. 

The knock on effect is that all the other metrics such as calories burned, zone minutes are all overstated.  And it calculates that I swim at just over 1 minute per 100 metres....No, I wish I did, but I only swim at a very modest pace of about 2 minutes/100m.  

Is there any other setting somewhere that needs to change in order for it to calibrate correctly?  

I'm happy to share the underlying data with the developers if that will help resolve the issue. 

Thanks

Andy

[AdukiBean]

Hi @AndrewGe 

I’m so pleased someone else is having the same issues as me. Thought I was going crazy. 

@DavideFitbit I’ve already tried the steps you’ve outlined above and can confirm I didn’t take long rests, kept a consistent swimming stroke and had it set to swimming - so auto recognition wasn’t required. 

I can try it again next time I go but I’ve included a screenshot here if that’s any use: https://community.fitbit.com/t5/Charge-5/Charge-5-swim-distance-incorrectly-calculated/m-p/5193455#M...

Thank you. 

[AndrewGe]

Correction.  Zone minutes are correctly calculated.  

@AdukiBean 

Thanks for adding to the issue.  

Do you happen to swim at Tooting Bec Lido?  

[AndrewGe]

@DavideFitbit 

@AdukiBean 

Further update after swimming in 91m this morning without setting an exercise activity.  Setting on 91m pool.  

Actual swim 20 x 91m = 1,820m

Constant swim stroke without stops.  

Recorded result

41 x 91m = 3,731m

It is odd that is has recorded an odd number of lengths when I swam an even number.  When I was using the exercise setting it was exactly double.  

@DavideFitbit 

Can this issue please be escalated to the developers as there are now at least three Charge 5's with this issue and I speculate that there is an underlying bug in the algorithm/s.   

Subsequent event:  After the swim I received a software update which I have now installed so will test this again tomorrow and only update if the issue is resolved. 

Ciao

Andy

[Lili-94]

Hi Davide,

I'm very new to Fitbit, but I've been swimming laps for more than 40 years :-[, and I change strokes during a workout, particularly now, when unfortunately I have to keep my heart rate lower.  I seldom change in mid-length, but it can happen if someone else is in the lane.  I've only tested it once, but like @AndrewGe, I found that my Charge5 over-evaluated the number of laps by about 20%, and it also counted an uneven number of lengths which was not the case. 

By the way, I had set the Charge5 for swimming.  To be honest, I kept the Charge5 even after learning I couldn't check my heart rate during swimming because I thought I could always interrupt the swim if I needed to check- less than optimal but the Charge5 has other advantages.     Are the constraints that you mentioned (same stroke during a length, no kickboard training, pause length) documented somewhere? 

Many thanks for your help!

[AndrewGe]

Hi Davide @DavideFitbit 

I ran a test this morning.  I changed the pool length on the Charge5 to 45m; almost half the actual pool length of 91m). 

I swam (either 20 or 22 lengths of 91m = 1820m or 2002m).  [Unfortunately I lost my count at one point.]

The result was 43 lengths of 45m  = 1935m.  

The swim rate is now 2'07"/100m which is much closer to my unremarkable capacity. 

SUMMARY

There is a fault in the Charge5 algorithm for swimming - certainly in a 91m (100 yard) pool.  

I will add this feedback to the AppStore to alert would be purchasers of this device and to hope that the engineers can get the bug fixed. 

Copying other contributors to this issue. 

@Lili-94 

@AdukiBean