Until recently, the only tool companies to offer batteries rated higher than 3.0 Ah in the U.S. market were Panasonic and Hilti (both sell 3.3 Ah batteries). That changed last week when Metabo announced their new Ultra-M 4.0 Ah batteries. I can vouch for the efficacy of high amp-hour cells because in a recent review of cordless drill/drivers, tools with 3.3 Ah batteries took two of the top three spots in the runtime test. It's probably just a matter of time before most, if not all, power tool companies offer 4.0 Ah batteries. Manufacturers frequently introduce tools overseas or in Canada before offering them here. I have no idea whether this photo of a 4.0 Ah DeWalt battery that is said to have been taken in Australia is real or fake, but this 4.0 Ah battery is on Hitachi's UK website.