Yeah, that is one way to do it, and usually I just plug it in to the computer anyway to charge it, but I just hate having to time it out so that I can plug it in to something that won't be shut down before it's done charging. The craziest part about it is that for the first time ever, it actually worked last night. My 360 fully charged my controller before shutting down all the way.
I have to think this an issue with individual controllers. I only own one battery back and it used to be in my other controller up until about a month ago.









