Disappointing battery life

Today, post-activity battery drain really got on my nerves.

Charged the watch overnight. Took it off the charger at 6:15 in the morning. Started a hike at 8:30, which went on for good 7:15 hours. I forgot to check the battery right after the hike, but I know 5:30 into the hike, the watch was still showing 63% of battery left. Pretty reasonable. About half an hour after the hike it was at 47%. Fast forward to 22:45, and the watch is reporting 29% left.

So, in 7 hours since the hike, in watch only mode, my watch ate through 21% of battery. That's like 3%/hour in watch mode and I barely touched it in that time!

I have this suspicion that the longer the activity, the more severe post-activity battery drain. I generally observer much milder version after something like an hour long run. But it can also be the lack of sync. Or the broken battery meter

I did restart the watch after the hike btw, a 47%. But I couldn't sync it - no cell coverage where I did the hike.

But the bottom line is, now I have to charge my watch again overnight, after mere 7:15 hours of activities, because I have a run planned for tomorrow and it might not last.

This thing is starting to feel like Apple Watch in frequency of charging it needs. ;-)

I may or may not have found something yesterday.

As posted earlier I have now turned off auto app update and grouptrack map display.

Yesterday I went for my first walk after doing this.

Unfortunately I only had 15% battery left.
For the first 20 mins the battery didn't drop and then for the remainder of the 2 hour walk it kept dropping until I finished the walk at 1%. After 30 mins it went up to 2% and the watch eventually shutdown about 5 hours later.

So a few interesting things from this.
1. 15% battery should only last 3 hours of GPS - poor battery guage theory
2. My walks are generally about an hour so maybe doing 2 hours meant that the battery guage caught up which perhaps for some reason it doesn't on shorter GPS activities.
3. No post activity drain, the battery recovered 1% but this is not unusual to see when batteries are no longer under load.

The only other thing worthy of note is that I usually finish my walks in a area of bad mobile signal and often the phone is unable to upload my walk or take a very long time, the last walk had good signal as well as the fact my watch appeared to lose connection to the phone as it didn't auto upload (probably because I was listening to music on my BT headphones from the phone) so I had to open the app.

Using my calculations the watch returned 85% of its stated battery life in the past week so I will see what happens with these new settings in the coming week.

So a few interesting things from this.
1. 15% battery should only last 3 hours of GPS - poor battery guage theory
2. My walks are generally about an hour so maybe doing 2 hours meant that the battery guage caught up which perhaps for some reason it doesn't on shorter GPS activities.
3. No post activity drain, the battery recovered 1% but this is not unusual to see when batteries are no longer under load.

That's interesting, and certainly needs more investigation. I've seen the opposite, as I posted above - the longer the activity, the more severe he battery drain after.

It's also possible that the watch behaves differently when the battery is on its last legs. I mean, when you get bellow 10%, it will refuse to boot up or sync via WiFi. There may be other checks that turn other non-vital things off and maybe one of these things is what causes post-activity battery drain. So definitely retest this when there's more battery life remaining.

Hello

i had the same issue on my Fenix 5 S Plus.
Charged full on Friday, today i reach 75% without doing any activities. Got less notifications last 2 days. Watch is up2date and connected thru my Android phone.
With reading this thread, i disabled now upload Data thru WLAN. maybe that helps.

I´m reachin a general battery life not longer as 4 or 5 days. Far away from 10 to 12 days.

Whats going on?

FWIW, I did a full charge last night and rode a 3.5 hour metric century this morning and I had 81% battery left at the end. 4iiii power meter was the only other accessory connected.

By this afternoon I am at 77%

https://connect.garmin.com/modern/activity/2889667055

FWIW, I did a full charge last night and rode a 3.5 hour metric century this morning and I had 81% battery left at the end. 4iiii power meter was the only other accessory connected.

By this afternoon I am at 77%

https://connect.garmin.com/modern/activity/2889667055

When you say "by this afternoon", how many hours after the end of the ride was that?

Thanks,

Neil

So since turning off Auto-Update & Group Tracking I fully charged my watch and took it off charge at 09:00 yesterday morning

It is now 17:30 the following day (32.5 hours later), during this period I have done 2*42 minutes cycling with GSC-10 & Premium HRM, 47 minutes walking, 40 minutes indoor Cardio with Basic HRM.

Using my previous values this adds up to
Smart Watch Hours (32.5-2.18) * 0.347222 = 10.52661375
+
GPS Hours 2.18 * 5.555556 = 12.12962875
= 22.6562425% estimated battery use

This again does not take into account non-GPS activity battery drain as we have no published figures for this but one would hope it falls somewhere between the two.

So my battery reading should be 100-22.6562425= 77.3437575%

My actual reading is currently 76%, which is not too far and so far not as far adrift as I have been previously experiencing

I am seriously beginning to believe that the settings I have now disabled may have been responsible for my previous post activity drain, fingers crossed.

Update: Now 4 days in and showing 43% with 10% unaccounted for battery loss, so still no better.

When you say "by this afternoon", how many hours after the end of the ride was that?

Thanks,

Neil

I checked after about 8 hours.

So, my F5+ should run out of juice in the next couple of hours. Currently at 4%. Looking back at the numbers I have noticed a bit of phantom battery drain following an activity. And I agree it appears to be larger, for longer activities. I expected a lower battery level when I finished cycling, but it was much less. However, by the end of the day the overall drain ended up exactly where I expected it. I wonder if there are some internal prioritizations that run during an activity, that affect the battery level checking algorithms. Then when you're done it slowly catches up. Will be doing a full charge and trying again to see if it becomes more accurate.

Overall though, I have been able to get from a full charge Mon, Jul 23 (100%), until now (4%) with 3 swims (55mins, 45mins, 60mins), 2 bike rides (60mins, 120mins) with HRM and Cadence sensors and a short treadmill run (20mins)

Jul 28
07:45 47%
08:30 46%
09:51 - 12:03 35% Cycling with GPS, BT HR and BT CAD + upload to Garmin Connect via iPhone (was expecting 16% drain, not 11%; saw 5-6% unaccounted for drain shortly after completing the ride, pehraps this is the watch trying to catch up).
20:06 27%
22:30 24% Spent about 20mins updating screens on my watch.
11% activity (11%)
14% smartwatch (49% - 24% - 11%)

Jul 29
07:45 20%
09:00 19%
02:35 16%
20:00 14% (did not wear for ~120mins due to some outside work).
22:00 13% 20 min treadmin run
1% activity (1%)
10% smartwatch (24% - 1% - 10%)

Jul 30
06:30 12%
07:30 11%
07:43 - 08:43 8% Lap Swimming (60:00) + upload to Garmin Connect via iPhone (3% drain after watch)
09:45 5%
12:15 4%
3-6% activity
3-6% smartwatch (13% - activity)

So in continuing to track my F5+ battery, I'm seeing roughly 8% drain per day just wearing the watch. Haven't done any activities the past 2 days, but today looking to go out for a 60-75km bike ride using external HR via BT and Cadence via BT. Probably a 2-2.5hr ride depending on weather today, so using my stat from Jul (8% drain for 1 hour), I should burn between 16% and 20% battery. Add to it 8% smartwatch and I should be down to 23% - 19% by the end of the day. Let's see.

Edit: Using iOS 11.4 on iPhone 6s, phone notifications disabled (e.g. no emails, texts, calendar), the following active screens: Last 4 hours HR, steps, stairs, Last Sport, Training Status, ABC, Weather, Music and lastly I use the Line watch face (displaying time, battery %, steps, calories, distance, HR, sunrise/sunset.

Jul 25
22:00 65%
12% activity (4% swim + 8% GPS)
8% smart watch (85% - 65% - 12%)

Jul 26
09:18 61%
10:57 61%
12:30 60%
13:55 60%
18:30 58%
21:45 57%
8% smart watch (65% - 57%)

Jul 27
06:50 55%
12:04 53%
21:00 49%
~8% smart watch (57% - 49%)

Jul 28
07:45 47%

I guess I can add in here to. I got a 5 plus a few days back, started a run at 97%, was out just under 3 hours, running GPS and Galileo, I think the backlight may have been on (but only at 5% if it was), and was connected to my phone and an HRM strap, but no music playing - finished at 63% battery.

So it pretty much drained 1/3 the battery. I’m finding the watch a touch heavy to my liking and was considering switching to the S but I think I’ll just stay with this given the battery experience.

That said - I’m pretty impressed with the watch overall.

My only other disappointment so far is the music connection to my headphones - they do drop if the watch is on my left arm which is my preference- but stay connected when on my right (jabra 65T elite).