Fenix 6 not holding charge

3 years is not that old, it is early for the battery to quit. Does the watch get hot when charging? 

I wrote about a similar battery issue at the end of the thread here: https://forums.garmin.com/beta-program/fenix-6-series/f/community-discussion/367583/26-95-battery-drain#1789159

New batteries are available. In the Fenix 6 the leads are soldered so replacing is a bit more finicky than in older models. But do try a full reset first.

Hello. Same here, it lost almost 30% of battery overnight in economy mode (no bluetooth, no pulse, nothing). It started happening 2 days ago...

Same issue with me. I started noticing after the update to 27 that all my functionality has been cut down by a lot. What used to be 2-3 weeks of charge now is 2-3 days of charge (this just started happening a couple of days ago). 

Same here and I think it is due to update 27 because suddenly started to do this.

Same here you beat me to it - a simple restart and problem is gone !

Good old computer advice always works lol

Update to the update:  Looks like I spoke too soon.  After reseting the watch it appeared top behave as normal, and gave the predicted 14d expectancy after charging.  For the first 6 days the watch lost charge consistent with the 14d prediction, until on day 7 I woke up to a depleted watch.  So the last 7 days of predicted charge disappeared overnight with no prior indication.  Something is still not right.

This is exactly happening to me. I even was in the situation that in the morning was showing 2 days left and at about 11AM when I looked at it, it was completely off with no pre warning of low battery or something.

Try disabling wifi and bluetooth connection over night. maybe this avoids depleting the watch.

Same problem here and on top of this, the watches are extremely slow.

Do you have the samw issue?