In short, no. Firstly, those ain't nearly as capacious as they say, you can be assured of that. Secondly, there's something where the wii needs 12v to turn on, so you'd really want 4 cells wired for 14.8v and regulate it to a stable 12. An 11.1v pack would maybe work if fully charged, but for most of the charge cycle, you wouldn't be able to turn on the console without some sort of up voltage regulator, and those are no fun.