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Battery drain: optical HR vs chest strap

Chris_Ffm
over 2 years ago

Hey all!

Going long I'm wondering what causes less battery drain: internal HR or external HR? Is this significant?

  • 0 over 2 years ago

    I'm not sure but don't you have to start an activity in order to make the chest strap work with the watch? In this case the Battery drain is much higher even if using an activity without GPS. 

  • 0 over 2 years ago

    I always use the external HR for running, I can't say I've noticed any significant battery drain - this is just my impression. Doing an activity is going to use up some battery power regardless.

    Listening to music/podcasts from the watch will drain about 10% per hour, that's definitely noticeable, but nothing like that with the external HR, so I don't think it's significant.

  • 0 over 2 years ago

    External HR uses slightly less. While you gain from not using the LED's, the ANT+/BLE chip uptime negates some of the benefits, so the overall difference is not that significant.

    Music is a major power drain, so nix that if you are going long. After that, look at your backlight settings (drop the intensity, cut the timeout duration, and After Sunset only). Also, GPS only, rather than GLONASS or Galileo. And turn off PulseOx.

  • 0 over 2 years ago in reply to mcalista

    Do you have any additional info re GPS only vs the other two, just curious, never occurred to me that this would make a difference. 

  • 0 over 2 years ago in reply to Levon

    From the 945 manual:

    GPS and Other Satellite Systems

    The GPS + GLONASS or GPS + GALILEO options offer increased performance in challenging environments and faster position acquisition than using GPS only. However, using GPS and another satellite system together can reduce battery life more quickly than using GPS only.