The last time I bought one of these the battery died after just over a year. I changed the battery and it started working again. You are not supposed to do that though, and black smoke started coming out of it shortly before it burst into flames. Looking for a new toothbrush I realised they are all so expensive, so I just bought the same one again due to its low price. Hopefully it will last more than a year this time. It is much better than manual brushing.
V