Matt has had his for several weeks and no trouble whatsoever. My first one, after its battery was first fully recharged, stopped holding a charge for longer than a couple days. So Jawbone sent me a new one a few days ago and the battery hasn’t yet needed to be recharged so I don’t know if my second unit is defective or not yet. But, goods and bads aside, perhaps the most telling thing for me is this: I’m not wearing it right now.