It has a dewalt pinout and does indeed work with american dewalt batteries.
When I first obtained the ryobi, I borrowed a 1.5Ah battery from my elders and was able to drive screws and predrill pilot holes for 11 hours. Because I use various different drivers in a single job, I cannot claim to know of any specific statistics that'd be useful to share other than it "lasted all day" without a blinking//critical battery warning.
