Really why didn't I get one of these years ago. I often have to cut large pipes or other metal where there is no power and grunt and strain to get something close enough to the power source to use my electric angle grinder. I really didn't think a battery powered grinder would have enough power to do the job I needed. In the end I had no choice and bought this grinder which WORKS with my Hitachi Slide batteries (as it should since they are from the same company). This thing ate whatever I asked of it, even faster than my electric angle grinder. I mainly cut 3" to 5" pipe with 3/8" to 1/4" wall thickness. He also used it to cut long strips of 1/4" sheet metal with ease. I have a 6 amp battery. This little grinder is quite energy efficient as I can usually get the job done without changing the battery. We look forward to many years together!