This is what I did to save battary

[Baysidefish]

I am sure it depends on the device itself. I purchased 3 Versa and returned one. I am wearing one and my gf is wearing one. On mine, I can stretch my Versa to 6 full days with 12% left. (Roughly, 15% a day)

Many of them were mentioned by other people

1. Drained battery all the way to 0%

2. Manually wake up

3. Brightness Auto

4. All day Sync off

5. Notification only enabled for two apps (no phone)

6. third party clock face (not the busy one)

7. did not use exercise app or gps (I do take a walk every day)

8. sync with app maybe 3-4 times a day

9. HR on

[GreginJaxFL]

Draining your battery to zero is harmful to the battery. You should not have to do anything to save power, just use your watch and recharge every 4 to 5 days. 

[Baysidefish]

I only drained it to 0 one time.