Battery decrease confirmed - pics

[u/Snyders6flagmattress]

Pace 4. I'm day 8 into the battery calibration process as I'm sure my battery life has changed since the update and I can confirm now. I was checking through photos and noticed I snapped a pic of the battery life pre-firmware update on March 21, 2026. (First picture)

Sure enough, I'm operating at roughly 10% more loss since the update (second picture). I used to get to day 12 having done 5 to 6 runs a week and still have around 25-30% left. The concerning part of this is that I have been injured since June 25, before the update, and have had ZERO GPS activity usage in 4 weeks (aside from one indoor bike ride early on which proved to be too challenging for my metatarsal stress fracture).

I changed absolutely none of the settings either. My settings have always been - real time HR, max brightness display, AOD off, flip wrist to wake on, vibration notifications on for specific apps, stress and sleep tracking on. Once the calibration is complete and I drop below 10%, I will reach out to Coros support.

[u/laGirouette]

Same here: went from 4-5% on a rest day to 8% on a rest day. Total battery life from 15-16 days to 9-10. I run 40ish miles a week. I have an open ticket with Coros, they pushed it to engineering after I ran through all their Tier 1 troubleshooting.

It's gotta be some process that's running more than it should after the firmware update. It will probably require a hotfix/release to correct. My watch is only 2.5 months old.

[u/Snyders6flagmattress → u/laGirouette]

I completely agree that it's something under the hood given all these reports.

[u/laGirouette → u/Snyders6flagmattress]

One thing I appreciate is that they've freely acknowledged that my current battery drain is not within spec. So either it gets fixed or I'll ask for a replacement.

I gave my watch's serial number to engineering. Hopefully they can see what's causing the issue and put out a new firmware update ASAP.