Battery lasts forever. Some metrics take a couple of days to be gathered but it measures a ton of things, and given that I don’t have to remember to charge it up once a day (unlike my apple watch) I get to wear it most of the time.
I'm very pleased with my purchase. The ring tracks my steps, workouts, sleep, vitals, stress levels, etc. Very easy to use with the app, but you have to purchase the app separately. The ring itself is comfortable and looks good on. Seems durable, charges quickly, and holds its charge.