Using Power Reserve
Power Reserve lets you see the time on your Apple Watch while preserving your battery life. While your Watch is in Power Reserve, it won't communicate with your iPhone, and you can't access other Watch features.
1.
From the Control center, tap the Battery Percentage.
On some watch faces, you can add a complication to show the current battery charge.
2.
Tap Low Power Mode.
3.
Scroll to Turn On.
4.
Tap Turn On.
To turn off Power Reserve, tap the Low power mode on.
5.
You've completed the steps!
