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Realistic battery life, fenix 5?

Hello all,

So last week I bought a fenix 5. Store had it in open box and on the shelf but it was off, I was worried about it having been on for months on the shelf but they told me it had never been powered on, they only had the 5X on display powered up. Bought it, no discount got home and charged it. The battery was completely discharged.

One of my main reasons for buying the fenix 5 vs a 3 or another less expensive option was battery life - as I am starting to run ultra marathons.

Last Saturday ran my first. I started with 95% charge. GPS only mode (no Glonnass). I played occasionally with the watch during the race, and often moved it into view to see my HR (with backlight at 50%). Halfway into the race, 7 hours in, I notice it is at 40% battery. I changed it to Ultratrac in the activity settings menu, and start avoiding using the backlight or play with it(still glancing at it often to see HR).

My race time was 14 hours 30 minutes. When I made it across the finish line, literally 1 minute after, I glance at the watch to stop the activity and it powered down.

I know actual, realistic device times are often lower than what the manufacturer advertises. Still, advertised GPS mode at 20 hours and Ultratrac 60 hours, seems I should have gotten to the end of this race with a good battery reserve. I am planning longer races later in the season so... this watch might not cut it, apparently. My iphone 7 plus in airplane mode, but doing GPS tracking, went through all of this with 30% power left and me taking some pictures and listening to podcasts on the way.

So question to the group - is this the normal battery life I can expect from this device while tracking activities? Or did I get a dud or a battery affected by it being a showroom device?

Unsure if I am just being paranoid and need to enjoy the device and go Ultratrac from the start, turn off the backlight (not needed to be honest).

Thanks all,

Juan
  • I can understand your frustration.. my wife ran her first marathon with her brand new Apple Watch 2 and it died after 4 hours (30min before she finished) without saving the workout :(

    I think the numbers advertised by Garmin are in perfect conditions... no backlight, no custom datafeilds, no widgets that auto update, BLE off etc...

    You need to figure out the best way of making the watch go the distance for you. I don't think you'll find a better option out there for what you want to do.

    Whether or not the battery was affected by being completely drained is questionable, although I believe the risk of this is very low. Draining the battery continually will eventually take its toll though.
  • It is actually advertised for 24hours. I started a race with everything off but navigation. It went dead just after 16 hours 55 mins of race. Too bad I needed to run almost one more hour... Next time I'll try without navigation... Not sure this will be enough for the extra 5 hours I'll need (for a 22h race < 24h). I'm not too happy with this...
  • Having a dud battery is a possibility, or perhaps the battery is fine but there is something in the watch that is draining faster than it should. But perhaps it is better to rule out some other possibilities before assuming it is a dud.

    If the watch is brand new, the battery gauge may not be be fully calibrated. A full charge/discharge cycle may give more accurate results in the future.

    Also, backlight can potentially be a significant power drain. In daylight, you shouldn't need it at all, although dawn/dusk can be problematic. 50% backlight is probably more than you need at any time. I find 20% does me just fine. Having the backlight activated by button press can also be an issue, as it is easy to leave on accidentally in daylight. You may want to experiment with different backlight settings, and measure the % drain per hour on shorter runs.

    BLE should normally use very little power, but it can use more if it is constantly connecting/disconnecting to your phone in marginal conditions. If you have your phone in airplane mode during an ultra, then there is probably little benefit in having the watch connected to the phone, so you may want to turn off the BLE connection on the watch.

    Another option is that using an HR strap will deactivate the OHR, which will also save battery life.
  • I have the backlight at 5%, enough to see whats going on. And its auto-off during the day (if I need it I can still hit the light button, as my old regular watch required me to do anyway) and at night it lights up with every button push.

    If your watch was in the shop for a long time and the battery discharged I might have discharged beyond whats healthy for the battery.
  • A possible fix might be to wear a HR strap and possibly a cadence sensor, and not wear the watch on your wrist but instead plugged into a USB battery pack. Workable if you are carrying some kind of hydration pack. Maybe not for the whole race but at least for a while to recharge it.
  • I use my fenix 5 since about 5 weeks. I had a two day race last weekend on sat and sun, each day for approx. 11h 30min. navigation was always on (GPS only, no Glonass) and also wrist HRM was on.
    i charged the fenix 5 from sat to sun. After each raceday, battery was still at 50%.
    I guess, battery should give power for about 20-22h. And this is absolutly ok.
    Advertising says 24h, but everyone knows, advertisings are always very optimistic :-).
  • Thanks all for answers. Nothing conclusive. Might be my fidgeting. Might be battery was affected by being on the shelf a long time totally drained. Just too much money and thought won't leave me alone, might try to get it exchanged or a refund (not as easy here in Europe vs the states).

    Some comments/questions:

    Quick question, what is BLE? It this Bluetooth or something different?

    Agree, backlight is not necessary. At night I had my head lamp, in the day it is perfectly visible.

    Charging during the run is not a possibility, as I understand it stops tracking while it charges. Or am I wrong?

    Is a chest band (meaning a radio transmitter powered on) going to consume less power than the optical? Slightly surprised by this!

    I spent some time in those crazy custom data screens with tons of measurements and graphics, but found them to small to be of use. Maybe half an hour? Most of the time was in a custom 4 data field screen, switching between two depending on what info I wanted to see. Always HR on screen.

    Thanks for the tips on how to optimize power usage. Appreciate the comments!
  • BLE is Bluetooth Low Energy, basically the latest bluetooth standard.
    If you go to Setting > System > USB Mode > Garmin you can charge while tracking.
    If you use a chest strap, the ANT receiver on the watch is active, which will probably use less power than the WHR LEDs (and is way more accurate)

    Give DIY datafield or Dozen Running datafield a try... with DIY you can customize the display to show you exactly what you want without having to switch between screens
  • One other suggestion. Perform a reset. If like most of us when we get a new watch :), you were experimenting with adding and deleting apps, etc, sometimes some stray code is left over, which can cause the processor to work harder than it should. A reset should clear this up.

    You can charge while tracking - it's just that due to the location of the charging port beneath the watch, you have to take the watch off to do it. Assuming you are using a powerbank or the like to charge it (ie. just power over USB, no data connection), then there is no need to change the USB settings.

    ANT+ and BLE wireless radios are designed to run hundreds of hours on a coin cell battery - they use far less power than the LED's in the wrist OHR. Although the wrist LED's are pretty efficient - and the advertised battery life is with wrist OHR on.

    I'd recommend trying the reset, backlight settings and the phone off, and see what battery drain per hour you get on shorter runs, before assuming you need to charge mid-run, turn the wrist OHR off, or that there is a physical problem with the watch.

  • I just did a 12 hour day high in the Adirondack mountain high peaks. From a full charge, GPS only mode, oHRM on, no external sensors, no bluetooth connectivity, no third party apps or data fields except ActivFace watch face, and I left the activity running even during rest stops, I was at 21% batter life remaining. Luckily I brought a battery pack to recharge after the hike.