When I first got my Vivoactive 4s, the battery lasted for about a week. Suddenly, it would drain over about 6 hours. I found some guidance about resetting it to factory settings and recharging, and it lasted for about 3 days. Now, it lasts for about a day. I don't know if any software updates had something to do with it, as I wasn't aware of the software levels from the beginning.
Also, if I plug it into my computer a certain way, it keeps vibrating like it's connecting and immediately disconnecting over and over. Is that normal? I'm feeling like I need to return it, but I really like the watch other than the battery life problem. If this is a problem with all of them, I'll look for another brand. If there's a fix or this is an anomaly, I'd love to replace it with the same model.