Charge 4 not registering heart rate

[Cheznrik]

Bit of an odd one.... but I bought a new Fitbit 4 last week and husband liked it better than his charge 2 so bought a 4 the other day. But... the heart rate monitor won’t pick up his heart rate .. it might find it for about 5 mins then looses it again... but If I wear it , it picks up mine.  So he tried mine and and again , wouldn’t pick it up.  But his charge 2 picks it up with no problem.  Have done a reset, and sync... any ideas anyone?

Moderator Edit: Clarified subject

[Rich_Laue]

Does your husband have any tattoos or scars under the watch?

[Cheznrik]

Yes.. has full sleeves on both his arms .. why? Would that make a different?? His charge 2 was fine

Sent from my iPhone

[LZeeW]

@Cheznrik   Fitbit's heart rate technology look for pulsations in tiny blood vessels just under the skin.  Tattoo ink is deposited in that same skin layer.  This is my How This Stuff Works explanation.  The Charge 2 has two green light emitters and one sensor.  The Charge 4 has one smaller light emitter, but two sensors.  Two lights reflecting back to one large sensor can pick up those tiny pulsations better than one small light divided and reflected back to two smaller sensors, especially in the presence of ink.

[Cheznrik]

Oh ok.... makes sense... but now unfortunately he’s stuck with a Fitbit that’s just cost £130, that’s not gonna work for him.. I’m very disappointed the Fitbit hasn’t mentioned about this problem with their products...

Sent from my iPhone

[AlejandraFitbit · Accepted solution]

Welcome to the Community, @Cheznrik. @Rich_Laue and @LZeeW, thanks for the input.

I understand how are you feeling and appreciate all the efforts in trying to fix this heart rate issue. Also, I was able to see here that our friends provided information about this HR problem. Were these the answers you were looking for? If they were, I recommend marking the answers given as the best answer. By doing this, other users with the same inquiry will be able to find a faster response.

Now, if your inquiry/issue wasn’t resolved, let me know and I will be glad to help you out.

[Cheznrik]

What can I say... Fitbit have just confirmed that if you have heavily tattooed arms/ wrist the charge 4 won’t work .. so now because I purchased it from another store I’m stuck with a very expensive watch that isn’t fit for purpose. Fitbit need to put this information on the description of the watch!!! Not happy at all. 

[dstangis]

Just purchased a new charge 4 - have had a charge 2 for several years.  The 4 seems to not register HR.  No tattoos - any other suggestions? 

[dstangis]

Just an update on this thread.  Charge 4 never picked up HR.  Packaged it back up and returned it.  Dusted off the Charge 2 and using that now until I move on to the Garmin products.  Hopefully someday, the design will be back to registering HR.

[soulfuldave]

If there is no tattoos on the under side of your wrist, then turn the fitbit round to the palm side of your wrist. I tried it , and now it works. I have tattoos on both top side of the wrist, but it works when i turn it it round.

[sheenamill]

My husband is having the extact same issues and he has sleeves as well. This really frustrates me. I appreciate knowing this though. 

[sheenamill]

We tried this as well and it only works half the time. Maybe we have a faulty device, sadly, we can't return it. 

[DrVeko]

I have never had the problem with my Fitbit not registering my heart rate.  I got a charge 4 for Christmas and the little green lights are on but it doesn’t register my heart rate and of course it doesn’t do my sleep stages because of this. Is it possible I have a defective unit?  I had the charge 3 hr and the charge 2 hr and they all did

[Cheznrik]

Do you have tattoos in your arms where the Fitbit sits?

Sent from my iPhone

[dstangis]

This is a common problem that has not been addressed. I've had to go back to a Charge 2 or switch brands to Garmin.

[DrVeko]

No tattoos.  Had my wife use the watch and it doesn’t work on her arm either. 

[Peggles11]

I've just found exactly the same issue. It doesn't work at all on my left wrist where I have tattoos so I'm now going to have to wear this on the other wrist and try keep the sensor between tattoos. 

It's a terrible design flaw that I hadn't even considered would be a problem!