After recent update, my Apple Watch's battery drains quickly.

Hi dcap.

Firstly you can check you iwatch battery health if it is below 80% then a replacement is recommended

Follow the steps below

1. Open the Settings app on the Apple Watch.
2. Scroll until you see the entry for Battery.
3. Tap on the Battery button and find the option for Battery Health.
4. Tap on Battery Health.
5. Here you will find the maximum capacity of your battery.

you can also take support from the article below to know all about your iwatch battery

Apple Watch Battery and Performance - Apple Support

Hi decap,

Responding to the message above. I recommend if you are going to use your apple watch consistently and do other activities other than just checking the time occasionally turn on low battery mode it lasts a lot longer this way.

The battery ir other hardware is sick. No way to burn that amount if battery using software.

In my user tip there us an overnight self discharge test.

Read through and try all of these

Apple Watch uses a LOT of battery - Apple Community

Try restarting the watch.

Restart Apple Watch – Apple Support (UK)

Update Apple Watch