I bought this product to help loosen latex paint before repainting. I haven’t started that project yet. I took it out of the package, put it together without charging it and used it on some tough indoor projects. I am amazed at the ease and efficiency this little gadget gives. I did not charge it, but have used it for about 20 minutes and there is no sign of decreased power. I do not do a lot of reviews, but had to recommend this. My back thanks you.