Garmin batteries

littledove44 Posts: 871
edited January 2014 in Road general
I was wondering how long the batteries in a HRM and GSC10 last?

Can't get my head round it . Do they transmit all the time?
Does the HRm only use the battery if connected to the strap?
Does the GSC10 only transmit when pedalling?
How long would you expect the batteries to last?

I don't mind buying new batteries but a shame to do so if they are only slightly worn out.


  • pinarellokid
    pinarellokid Posts: 1,208
    last about a year or so. but only cost pennies cr2032
    Specialized S Works SL2 . Campagnolo Record 11spd. rolling on Campag Zonda wheels
  • Mikey23
    Mikey23 Posts: 5,306
    They only use juice when they are transmitting. For the speed magnet that's every time the magnet passes the sensor. I think It said in the leaflet that it will last about a year if used for about an hour a day. Don't know about the HRM but I would assume similar. Just wait till they stop working. And don't always assume its the battery when they stop cos often it isn't.
  • Thanks.

    Just don't want them running out during my trip. Will replace them beforehand.
  • Secteur
    Secteur Posts: 1,971
    I had to replace the batters in the cadence sensor after 2 years, and havent needed to do anything else.

    As above, the battery cost pennies off eBay or Amazon or somewhere, and it's extremely easy to fit.

    It's probably worth changing every year just to keep it fresh.
  • Secteur
    Secteur Posts: 1,971
    How odd - after typing the above post, I went out and the battery in my cadence sensor is flat!! I only replaced it a few months ago, so I wonder if maybe it's water ingress... will have to take it apart and have a good look!
  • ricey155
    ricey155 Posts: 233
    be prepared when the batteries run out the device normally gives up at the same time.

    I've had issues with both HRM and cadence sensor thinking the battery had gone only to find out, they just gave up the ghost luckily one was still under warranty

    on the upside the cadence sensor replacement seems to be a lot more water resistant, even tho its looks the same