I Bought this over a year ago and the battery lasted at least 9 months and it was great up until then. During these 9 months I had swam with it on, went in the shower and also gotten it it wet multiple times. It died just when the 10th month hit and from then on it was just going downhill and even when I took it to the watch maker they couldn't fix it, After I went the final time this guy fixed it and said that actually they are not water proof and that I was lucky that it hadn't fully died on me. This is not to say it can't get wet at all, it is splash proof, so it can get a little wet but not fully. So just before you go swimming make sure you take it off or it will die and there is nothing you can do about it. Happychappy