Heart rate radically different after switching from Charge 5 to Charge 6

[Sesquiterpene]

Hi everyone,

I recently (ca. 10 days ago) switched from my Charge 5 to Charge 6. I am generrally pleased with some new features, but the HR monitor gives significantly different results.

In some cases it feels more sensitive: when increase peadling my bike, HR goes up as expected - which I did not see as clearly on the Chrage 5. However, in general HR on the Charge 6 is substially lower. This is most manifest in simple rather brisky walking, which always put me on 100 to 115 bpm on the C5, but is now more like 80 to 95 bpm. Similarly, when I lift weights I am about 20 bpm lower than the C5. 

Cycling is a few points lower than in the past, and running appears to be more or less similar to the C5.

I have no other experience measuring my HR so I have no clue which one is more accurate, but the sitaution is that either I completely overestimated my HR in the past, or it is being underestimated right now. 

Anyone has a similar experience? 

[LZeeW]

@Sesquiterpene   Fitbit changed the heart rate algorithm between the Charge 5 and 6.  It prominently advertised improved heart rate monitoring in the release advertising.  Fitbit put that same algorithm on other current models in a firmware update.  I noticed changes after it got added to my Sense 2.  Yes, others see the same thing.

[Sesquiterpene]

@LZeeW  Thanks! 

I wonder if they will update the readiness score and recommendations. I don't use it that much but my movement points have crashed after the change and reaching the recommended 180 per day is suddenly not as easy as it once was...

[LZeeW]

@Sesquiterpene   Fitbit is changing the readiness score calculation, too.  Help article  I haven't received it, yet.