Battery life on Apple watch 4

All I can offer is this advice:

Understand Apple Watch performance and its relation to your battery.

Apple Watch Battery and Performance - Apple Support

“Battery life” is the amount of time your device runs before it needs to be recharged. “Battery lifespan” is the amount of time your battery lasts until it needs to be replaced. Maximize both and you’ll get the most out of your Apple devices, no matter which ones you own. See the "Tips for Apple Watch" section in:

Batteries - Maximizing Performance - Apple

I am having this same exact issue on my Apple Watch 4 that I've had for less than a year. I can normally go an entire day without needing any recharging. By the time I go to bed (approx 14 hours of wearing) the battery is typically in the 40-60% range. However, since Sunday (5 days ago) my battery is almost dead by late afternoon/early evening.

Additional to this, I have been using my old Apple Watch 2 since buying the Apple Watch 4 while I sleep for sleep tracking. When I put that watch on before going to bed, it is always 100%. Normally when I wake up (6-8 hours) it is still around 75% battery. Now that watch is dead by 3-4am (approx 4 hours). I have theater mode on while I sleep, so there is no screen waking at all. This issue also started Sunday.

I have tried hard-resets as well as complete wipe and restarts, but neither of those solutions worked. There is definitely something going on with the software. Its not hardware related, as both of my watches are suffering the same issue.

Me too! It’s since the last update!

I have the same problem, but it started before the latest update was applied