Apple Watch Series 3
The battery life of my Apple Watch is short
Solution 3 of 3: Low Power Mode has been turned off
Some functions on your Apple Watch use a lot of power and therefore significantly reduce the battery life. You can reduce the power consumption by turning on low power mode.
Slide your finger upwards starting from the bottom of the screen.
Press the battery percentage.
Press and drag the on icon right.
Press Proceed.