Fitbit Charge 2 Accuracy

[George_V]

Hello Charge 2 Community! 

I have recently upgraded from Flex to Charge 2 as I wanted to have more clarity about my heart beat while training (mostly weightlifting). I have been using charge 2 one week now, and I am rather disappointed for the below reasons:

1. HRM is totally away from reality...I can have a real rate of 160 bpm, while charge is showing 110 bpm... checked similar topics and I found out that this is a common issue for charge 2. Only when I totally relax my arm charge 2 starts to pick up the correct heart rate. I haven't found a solution yet, if there is one. 

2. I noticed that my steps were decreased when I started using charge 2 (under same activities), so I have been wearing both charge 2 and flex simultaneously and I have observed charge 2 lagging 500-800 steps on a daily basis compared to flex. I trust flex readings to be honest. I have noticed that charge 2 in several occasions it stops counting and when it resumes it does not account for the missed steps while it was idle!

3. Finally I even noticed difference in the measured sleeping time between charge 2 and flex. Charge 2 shows me having slept less ~30-40 mins which is a significant difference. 

Please let me know if you have any tips for the above, as I am seriously considering to have this device returned. 

[HeydyF]

Welcome aboard @George_V! Let me give you a hand on this. 

Let's begin with heart rate readings. In order for you to get more accurate results, please take a look at this help article: How do I track my heart rate with my Fitbit device? And follow the tips t get better results. 

In regards of the steps, I suggest you you not to wear both devices, the Flex and your Charge 2 at the same time and for the same activity, 'cause at the moment to sync, the data might messed up. If you see that your Charge 2 misses steps, try a step test accuracy. 

Now about sleep, since the Charge 2 has heart rate monitor, the sleep data will also be more accurate that the data tracked with your Flex. Anyways, you can try to restart your Charge 2 by following these instructions. 

Let me know how it goes! 

[George_V]

Hello @HeydyF thanks for the response!

Regarding steps counting I tried all possible combinations of hands, both on dominant and non-dominant mode. Conclusion: Charge 2 is very conservative when worn on non-dominant wrist and very sensitive while on dominant (if I shake my arm quickly it counts steps!). Flex demonstrates a more balanced behavior. In general there is either a leading or lagging difference of ~800 steps on day of ~10K steps between the two devices. 

About heart rate I give up! I will buy a chest strap to be sure. The HR is lost all the time and takes much time to pick up heart rate again. As I need to monitor HR between my set this is not helping. 

Regarding sleep monitoring I will trust what you say as it sounds reasonable. I would like to share though that a couple of nights I did not get sleeping insights, because as per the app message the device was unable to capture the HR.