Inaccurate heart rate

[mightysparks]

I have been using my Fitbit for about a year with few issues. For the last few months I’ve been doing C25k on the treadmill and my heart rate readings seemed to be pretty accurate, peaking at 150-160. For the last few weeks I’ve been running outside, which is much harder and I can feel my heart beating like mad and my max reading is... 120. I’ll run for 3 minutes and it says 120, I walk for a minute and it’s down to 65. My resting usually says 48-54. I know I’m working at least as hard as I was on the treadmill! And I’m not that fit, average at best. 

I’ve tried loosening and tightening the band, wearing it higher on my arm, stopping for 10 seconds now and then, resetting the device. But nothing. Is there anything else I can try? Is the charge 3 more accurate with it’s readings at all, as I’ve also considered buying a new device?

[Maldri]

My charge 2 is not accurate either. It shows 145 beats when walking . I have to test charge 3 on my right arm so I can check it out. The 3 shows 116 beats . so something is definately wrong with charge 2.