Make your Watch last longer
> You can improve your Watch’s battery in the following ways… Choose a minimal watch face design (or switch off Display & Brightness > Always On). Enable Reduce Motion under General > Accessibility. Connect to your iPhone via Bluetooth for connectivity. Then follow the same suggestions for your iPhone, such as minimise app and email notifications, reduce brightness, and so on.
Cut down on effects and colourful screens to get more battery life from your Apple Watch.