Maybe some of you guys can help me out on this.  I have never been able to effectively charge my controllers using my 360.  Let me explain the different scenarios:

1.  I'm playing a game, I see the warning on my controller that the battery pack is going dead (or I just let it die completely), and I plug it in to the 360 via the USB controller port.  The red charge light comes on, and the controller charges as I play.  However, if I turn the 360 off and the red charge light is still on (meaning the controller isn't fully charged up yet), it will only continue to charge it for about a minute after the 360 is powered down and then shuts off completely.  When I power the 360 back up, the GREEN charge light now comes on, meaning that the 360 is seeing the controller is fully charged, even though I know full well that it's not.  Obviously if I play long enough after I plug it in, it will fully charge the controller eventually and this is not a problem.

2.  Same scenario as above, except after powering down the 360 and having it unsuccesfully charge the controller up the rest of the way, I plug into a USB port on my computer.  In this situation, it's the same thing.  The green light comes on as soon as I plug it in, meaning my computer is also seeing the controller as fully charged.

3.  Just to make sure that I'm not imagining things, I let the controller get really low on power.  While the 360 is powered on, I plug the charger in, immediately unplug it again, and then plug it back in.  In this situation, there is absolutely no way that the controller is completely powered up when I unplug it and then plug it back in again.  Even so, when I plug it in the second time, the green light comes on meaning that the controller is not charging.  The battery indicator also shows it as being full.

There is really only one solution to this problem, and that is to leave whatever machine I'm using to charge the controller (360 or PC) powered on overnight in order to insure that the controller gets a full charge and not just a "fake" charge that will only last about a half hour.  Now I sure as hell am not going to leave my 360 on overnight.  Leaving the PC on is not a problem at all, but then I have to carefully time out my battery usage.  I can only plug the controller in once during the charge process.  If I interrupt the charge process and try to reconnect, it's a no go.

Now, here's the kicker.  I bought the Orange Box today and was playing it for about 2 1/2 hours tonight.  My controller started going dead, so I plugged it in to the 360.  I turned the 360 off about 45 minutes ago, and it's actually still charging my controller!!!!   This is the first time it's ever charged my controller as advertised (it's supposed to finish charging even when the 360 is powered down). 

Have any of you had this problem or had it work on an inconsistent basis?  I've been a 360 owner for a year, and tonight is literally the first night this has ever worked right.  My brother has the same problem, but a friend of mine says his 360 charges his controller after it's turned off with no problems.  The only explanation I can think of is that I switched my rechargeable battery pack to a different controller recently.  Maybe it's an issue with some controllers.  I don't know.  Any thoughts?

you know what happened to me. The exact opposit. I didnt realise the controler charged while the 360 was off and I still had it in and shut down my x box but I could still hear the fan. And I was like "whats going on here" and then I realised it was cos my 360 was actually charging the remote! hahahaha noob i was! I should have read the instruction manual lol. Any way, I havent had any trouble but my remots seem to charge quite quickly and their good to go, fully charged :D

Some times what I will do is plug it in while Im watching a DVD on it, that way I kill 2 birds with one stone. that could be a possible way for you to charge it seeing as though I think it only takes an hour or so to fully charge.

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.