I think the battery-powered ones are simply just weaker. Making them as powerful as the corded versions means shorter working times and you have to re-charge more frequently. Mine was also getting jammed with hair clippings that I had to clean them out after every use. My corded clipper on the other hand has barely any hair on it after use and a light brushing cleans it up. It also has fewer nooks and crannies for hair to get stuck in.