After the orange light goes out, if you leave the DS plugged in, does it run off the battery or the ac adapter? I say this because even if I charge it full, if I unplug and replug after playing for a while, it takes a while to recharge.
Yeah, then you can turn it back on and play for another hour or two (which I have done beforeAlso, the battery does not become fully depleted. The DS turns off when the battery reaches a low (not empty) level, so you don't need to worry about that.

