Are you doing 'workouts' or using the map? Custom data screens / watchface? Check the backlight setting to not be on all the time in workout.

I ask as my 935 burns battery when in workout mode, and especially if I'm using it for navigation to follow a route when cycling. But I had 40% left when I finished IMNZ.

I would recommend turning off wifi sync and smart phone notifications to start. Those two seemed to really suck battery life on my fenix 5 plus. Also, activity tracking/continuous HR can affect battery life as well.

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tinman

Thanks for the input. I've never used map and the backlight was set to come on but not constant. I turned the backlight completely off. The only adjustment to the watchface was to go through the options and customize so I only see the time, date, and the batter percentage. But I haven't downloaded any watchfaces etc.

Maybe the backlight being completely off will help.

Nah, I have mine to come on after button press. So it shouldn't be that.

I got my wife a Fenix 5s for Christmas. Battery life was way less than expected, charging every 4-5 days. Worked with Garmin. Tried all the fixes mentioned. No luck. Replaced. Still no better. Hopefully an update will help at some point. Battery in 5s has to be smaller. Pretty aggravating considering the cost.

Not a Fenixuser, but use 735. If you turn optical HR as well as Bluetooth off I’d think the battery would last much longer.

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I don't have a good answer for you...at IM Florida 2017, I used my Fenix 5s on Multisport mode. It died about a third of the way into the run. I had all extras turned off and was on 10sec GPS instead of every sec monitoring.

FWIW, I plan on using my Fenix 5s for the swim and the run at IM Santa Rosa next month and use my Edge to record the bike segment. That's the only way that I can envision my particular watch lasting long enough. I won't end up with a single multipart file, but at least I'll have my data.

I'm having the Fenix 5 sapphire (not s version) - and I have more than 20 hours of battery life. DCrainmaker has made a review. The official max for 5s is 14 hours tracking time.
Have you tried using ultratrac mode?

I have similar battery life from the Fenix 5 Sapphire as well (20+ Hours)

I was just thinking on my long run this weekend, “I wonder if there is a way to set up a completely blank screen to save battery and then have it pull up data when I press a button.” Kind of like the functionality of the backlight but have a blank screen option. Is this a thing?

You guys know if it’s possible to have turning off those various features be tied to an activity?

In other words if I do Triathlon activity it automatically turns off Bluetooth, backlight, etc, and then when activity is over reverts back to those functions being on?

No....but its not that hard to turn them off then back on

Agree it’s nkt hard. But also one less thing to worry about or futz with.

Quick update: There is absolutely no way the Fenix 5S would have made it through IMTX on Saturday. I turned everything off except the GPS and only used the watch for the swim and run because I didn't trust the battery for the bike. It dropped to 53% remaining on just the swim/run which combined for 4:45. So it wouldn't have made it through my 5:30 bike leg and transitions if I would have used multisport mode - unless the battery indicator is way off but didn't want to test that on race day.

Disappointing to spend that much expecting a watch to make it through an entire IM with both GPS and heart rate but find out it can't even do it without the HR function. Basically a $500 swim watch for me since I already had a 230 which works great for the run.

The 5S gets its smaller size in part by reducing the battery, so life will be less than the 5 or 5X. GPS is the big battery suck (I'm assuming backlight is off). Ideally you only need GPS for the run (to get pace), and can get speed via ANT+/BTLE sensors on the bike.

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