Symptoms
- Watch loses a large percentage of battery overnight with no activity
- Battery percentage drops faster than it used to
- Watch needs recharging more often than when new
- Overnight drain worsens after an update
Likely causes
- CommonAging battery losing capacityBatteries naturally hold less charge after roughly 1–2 years of daily cycles.
- CommonSleep tracking or continuous heart-rate monitoring running all nightOvernight sensor use draws more power than idle standby.
- PossibleA stuck app or sync process running in the backgroundA misbehaving process can prevent the watch from properly entering low-power standby.
- Less commonFirmware bug introduced by a recent updateSome updates unintentionally worsen standby battery behavior until patched.
What to do
- Check the companion app's battery usage screen to see what's consuming power overnight.
- Temporarily disable continuous heart-rate or sleep tracking for one night to see if drain improves.
- Restart the watch before bed to clear any stuck background processes.
- Update the watch's firmware if an update hasn't been applied recently.
- Track battery percentage at bedtime and wake time over a few nights to see if the drain rate is consistent or worsening.
- If the watch is over a year old, compare this drain to its original performance to judge battery aging.
When to call a pro
If overnight drain is severe and consistent on an older watch even with tracking features off, the battery has likely degraded and needs professional replacement.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.