The battery life is very good. We probably change them every 10 months or so, and thats with a daily weight in for each of us. The one thing that irritates us, my wife especially, is that the kids jump on and then weight themselves. The domestic has also done it on occasion and then for some reason they manage to override the ?? on the screen and save the stats under one of our profiles. And you normally only notice the next day as when you stand on it it doesn't recognize your weight and associate it with your profile, so then its then a manual process of going into the app, deleting that weight in, letting the whole system sync and then getting back on so that when you weight yourself it once again can associate your weight with your profile, and then save it accordingly. Bit of a chore but its maybe 2 or 3 times a year so not that much of a deal.