[AT&T Samsung Galaxy Note I717] CPA Poke:
Try your preferred mobile repair shop first.

I had this exact same problem a couple weeks ago...it all started one day at work when I had my phone plugged in (as I usually did if it was in one place for more than 5 minutes), but after turning on my screen for the the first time in an hour or so, I noticed that it hadn't charged at all! The indicator at the top didn't even show that it was plugged in.

Figuring it was just some kind of little glitch, I unplugged it, blew inside the charge port as well as the cable (old Nintendo habits die hard lol). Well as I went to plug it back in, I realized that NOW the indicator showed it was "charging", and my phone had gotten super hot in just the 30ish seconds it took me to blow the port and cable (heh.)

So obviously I freaked out and immediately shut it down, pulled the back, and removed the battery to let the two pieces calm down and make nice - before ultimately putting it back together and booting up after 15 minutes or so.

So the good news was that the "reverse charge" issue was gone...but the bad news was, the charge activity started acting literally word-for-word like your girlfriend's. Intermittent charging when it was sitting still, not charging at all for a period of time, losing more battery than it was gaining while it was plugged in and the screen was OFF...so yeah, it sucked. I did notice that I could push the cord back while it was plugged in and it would stay charging, but obviously I can't sit in one spot holding my phone for 5 hours a day - and that stopped working after a few tries anyway.

I spent countless hours on the internet, googling different phrases to try and find similar instances of this happening - but to no avail. Everyone's story was just a little different...and pretty much everything I found outside of XDA* was written by people over in England who dropped their N7000 in the snow, causing the charge port to be corroded. The conclusion from everything else I found regarding this issue for the i717 was essentially always "the only way you can fix this is to get a new phone, but you're screwed because this glitch causes the phone to look like it has water damage and therefore renders it ineligible for manufacturer warranty claim or even insurance claims".

To make matters worse, not only was my phone effectively unchargeable, but it was discharging at an absolutely absurd rate. I'm talking approximately 20% every TEN MINUTES!

So I got desperate (it's Sunday by now)...all of the cell phone repair places were closed where I live, but I was able to do some searching and found this guy that was surprisingly available at the AT&T store closest to my house. That kept me alive until Monday, when I was able to take it in to the guy who I've been going to ever since the iPhone days (he is FANTASTIC). So he looks at it, takes it apart, and in about 5 minutes he tells me that the small little strip where my charge port attaches to the mother board (or whatever) had a lot of cracks running across it that were causing it to short-out. He said that it's a very common problem with the AT&T Galaxy Note, I guess due to them using a pretty cheap part in that regard. This obviously explained the intermittent charging, the brief "reverse charge", and even the battery drain (if the motherboard was shorting out).

So what did he do?

Replaced the little strip that connects the charge port to the motherboard...took him half an hour...cost me $25. Advised me that, when I plug my phone in from now on, to try as hard as possible to keep the phone still and not move it around. So at least in my case, it was NOT the battery. If you'd rather be cautious and not take the phone into a store if you can avoid it, you can probably get a replacement battery online for just a few bucks and at least eliminate that.

So the moral of the story is: DO NOT try to take the phone in to AT&T store or deal with your warranty/insurance until you take it in to a decent repair place and have them take a look at it.

Hopefully this helps...I'm sure you are wanting (like I was) a software solution, but it is what it is. And just curious, did your girlfriend have any similar "reverse-charge" instances like I described above?

tl;dr: The problem is the charging port, not the battery. Should be an easy and inexpensive (<$50) fix at a legitimate cell phone repair location.

*The silver lining in this whole thing was that it caused me to stumble upon this forum...so I went from stock ROM, stock everything (before my charge port issue) to having flashed about one ROM per day over the last 5 days because I've been so interested in the entire world of customization that I only discovered after seeing a thread with "Gubment Cheeze" in the title (who WOULDN'T at least look at that to see what's up??) here on XDA and starting to read. I've been a 24/7 lurker ever since :) :cool: