The Ni-MH batteries lasts on an average about 8-10hrs of continuous play. One of the battery cases is loose as it does not locks in completely so sometimes it loses its connection in the middle of the game. Overall good for the price!
I got these a while back. They were complete junk. They arrived quickly, so that's good. They were cheap enough that I figured I'd take a chance on them. They do not have external power. They need to be plugged into the Wii or some other USB port. A generic USB charger with USB port is just fine. It did not come with any instructions. The charger lights up quite a bit. That is pretty annoying when trying to watch television or a movie in a dark room. There were two different colors of light. I assume one means charging and the other means charged - but I have no idea which is which because the color seemed to be random. I let the controllers "charge" for 24 hours. At the end of 24 hours, they had no charge whatsoever.