Too bad this has to be theoretical. It is assuming that you can deliver as much power to the battery as it can take in a fraction of time. This is the way I see it working out for me:

My battery is 85 Whr 9-cell battery. This translates to 3600*85 J = 306 KJ. I use a 120W power adapter for my notebook and I guess it uses around 60W when I'm doing regular tasks. So I can only deliver 120 - 60 = 60W if I try to charge the notebook while its on. 60W * 10 min = 36KJ. So it would still take me 85 minutes to charge at that rate. Even if I turned the computer off and the battery got all 120W, its still gonna take 43 minutes. True I have a large notebook but this has to extrapolate decently to smaller notebooks due to smaller batteries/power bricks.