battery holds its charge for several cleanings....even though I've used it several times, still trying to get the hang of where to hold and at which angle to hold so that when my mouth fills with the water I spit it out and it usually flows down over the unit....I know this isn't th3 most efficient use but haven't quite figured it out yet.
I bought this a month ago and it's the best investment I have ever made when it comes to oral health. I will never use dental floss again. I've only used my waterpik on the low setting and that's enough. The waterpik is very powerful and easy to use.