Disappointing battery life

Charged to 100% before I went to sleep, woke up at !!! 79% !!!, crazy. I took a charge-cable to office so I did not have to charge before I did my morning activity. 50min of running with GPS+Galileo, no music, HRM run, and at 63% now.
BUT, I noticed that I have received FW 4.2 over night. As I have not provided WiFi, this must have been the reason for the discharge over night. Quite risky, to do a FW upgrade while not on charger and without approval of owner. But at least that explains the drain overnight.
Now let's hope that this FW gives some positive feeling :)

I tried yesterday to check in garmin express if there is the new version to download and the watch battery was 56% and i charged it till 70% and i went to sleep(shut down every night the watch)today i opened the watch and the battery was 96%..something wrong here and it isn't the first time that happened....

I upgraded to 4.20 yesterday and had 44% battery. 24 hours later without any activity the battery is down to 31%, a loss of 13%.

This is worse than before as I used to get 8% per day in smartwatch mode

Have similar experience after upgrading to 4.20. My 5s+ now uses approx. 3% per hour in smartwatch mode. Connected to iPhone but apart from that have not installed anything, connect iq or otherwise. Have tried both hard and soft reset but so far no improvement seen.

Yes, 4.20 made thinks worse it seems. PABD is still there, but it's now on steroids. I think at about a release 6.00 at this speed it will get to apple watch category - you'll be lucky to get out a full day of battery out of this thing. I'd say enjoy this watch while you can. ;)

Received my 5 plus last thursday , charged to 100%, played a lot around in the menus , stay’d outside one hour with gps for calibrating, used for 3 1/2 hour indoor cycling with backlight on , used as a daily tracker with 1 second registration. Now after 4 days down to 55%. I am happy with that , did not expect more .

Have similar experience after upgrading to 4.20. My 5s+ now uses approx. 3% per hour in smartwatch mode. Connected to iPhone but apart from that have not installed anything, connect iq or otherwise. Have tried both hard and soft reset but so far no improvement seen.

I also have a 5S Plus, but am not seeing worse battery life after upgrading to 4.20. I can get about 5 days in smart watch mode, but if I put in two 45 minute workouts during a charge cycle in which I use GPS and music, it will last for approximately 3.5 days. While this is substantially worse than my 5S, the 5S Plus has more features that make it worth the difference for me.

I too am noticing an even bigger decrease in battery life after the 4.2 upgrade. I'm now losing 13% a day without any activities.

Even after rebooting my watch yesterday, an act that prior to the update would correct any excessive battery drain, my watch is losing 0.5%/hour instead of 0.35%/hour. This means that instead of being at around 40% like it should be, the battery is now at 16%. Battery drain has definitely increased since the latest update.

Are you having all your apps sending smart notifications I limit mine to text, phone, WhatsApp, and slack. My recent tests showed on days I did not use the device for activities, maps or music I was at c8% daily drop, and so far today on 4.59 beta last c12 hours, I have had no noticeable battery drain,or on any code base bar my first two days of the watch.

If I had this issue suggest factory reset, do nothing bar a full set of syncs, measure battery drop daily, then start adding on sensors.. So don't setup WiFi day 1, or smart notifications or garmin pay and don't do any activities or map usage. Also disable OHR.

Helps if you have another fenix {still got my fenix 3} to allow such a test. Then your doing a progressive UAT test cycle.