Fully charged at 3 bars, used High dropped down to 2 bars. Attached a tip incorrectly would generate high pitch noise and not work right, such as lost power. It can chip plaque at Mid and High, but at High, the tip became HOT and lost power fast. Only has a 600 mAh battery. It requires a charge more often.The kit doesn't has right direction how to use it. The kit is hard to use. It is most to hurt my teeth. I don't want to use it again.It’s junk. Worked once and never againPerfect for hard to reach places, the lights helps out a lot when trying to find plaque. Didn’t floss as much as I needed too in the past, but with this tool you couldn’t even tell. My teeth feel brand new. It won’t drill on gums, very safe! Keep tongue away, it might get warm/hot and catch you off guard but definitely not painful at all. Noise is the most annoying thing but that just shows how precise this tool is in my opinion.the set is not very intuitive to use and try out the three levels - the lowest level doesn't seem to do anything and the highest one drains battery pretty fast and can be a tad painful on the teeth. The instructions are not very detailed; one needs to experiment with various heads/settings to find a comfortable combo that can then be effective. While the battery is rechargeable, its capacity is just ok. Overall, cannot recommend enthusiastically at the price point of around 40.when I first turned it on, I thought it was broken up until I touched it to my teeth, then I felt the vibration, and boy that was a trip haha. be very careful with it, and definitely look up what to do and what not to do with these.My kit arrived with the seal open, not sure now if it’s a used kit because it was open and the case had dirt on it . Very disappointed because this is a danger to my health.