has never let me down. Batteries have never deteriorated over the years and still last a few hours even after a few years. Unfortunately, this last purchased 20v is not like the previous exercises. I think they made saving tech changes a safe money. The torque controller itself keeps dropping to a lower torque and then starts clicking. It started a month or two after receiving it. I will try to buy another one but if I get the same results I will switch to another brand.