Artificial light works perfectly

The best way to recharge the watch, especially if it has more battery, is by sunlight; artificial light only maintains the charge level. To reset the watch, press and hold the button in the bottom right-hand corner. It will try to synchronise itself. It's best to do this near a window.

PS: how long does the watch take to fully recharge?
And when the battery is full, is the watch automatically set by the watch itself or do you have to press a few more buttons?

Thank you in advance for your feedback.