[Nexus 7 Q&A, Help & Troubleshooting] PalmerEldrich:
I have a little insight to share on this topic that might apply to some of you.

I bought mine back in december from costco and had no issues up until last night.

Up until then it had been sitting on its official charging dock by asus underneath my TV plugged to a big UPS along with my TV and amp.

Last night I decided to move it into my bedroom cause I wanted to start using it as a clock and to listen to music or podcasts before sleeping and to wake me up. Even before I got the dock the OEM charger was always done within 2.5 hours at most from a very low state like under 10% cause I was using the hell out of it back then.

I had to do 2 things in order for this to be practical for me.

1. The damn usb cable they give you is so short you couldn't hang a mouse with it so I changed it for one twice as long.

2. I plugged the OEM charger and dock to a APC Surge Arrest, Not a piece of crap power bar (or so I thought).

And here is what happened.

I went to bed with the battery at about 22% and when I woke 8 hours later the battery had only managed to get up to 57% which is unacceptable.

I then did 1 thing I unplugged it from the APC Surge Arrest (POS power bar that I might soon throw in the trash!) and straight to a wall outlet. I did not shut it off simply put it on sleep/standby instead of letting it be daydream clock.

Then I came here and read this thread, I at first had the suspicion that maybe it was the USB cable I switched but after reading somebody's comment about polarity I thought perhaps I was a tired last night and plugged it in the wrong way. It's pretty easy to do that actually and its still a possibility that it was plugged to the APC the wrong way.

After reading all the comments here and getting a coffee, Which maybe took me 10-15 minutes at most I went back to check on it.

At this point it was already at 60%. Then instead of putting it to sleep I just let it as I normally would on Daydream clock and by the time I finished typing this message it was at 65%. This fast charge is normal for the dock.

So problem is solved here it was the power brick that it was plugged to or possibly the polarity. I am going to know today if that is the case because I have a Nexus 10 charger that I also plugged into that same power bar last night so next time it needs a recharge I will keep an eye on its progress. If the Nexus 10 charges up fine then either the ASUS charger does not like the APC Surge Arrest or it was plugged the wrong way or the outlet on the APC that I used was bad or something and if its the latter that thing is still going into the trash.

For those plugged with the charger straight to the wall I would recommend the following.

A. Make sure its plugged in the right way or just reverse however its plugged in now.

B. Try another outlet and if that's also slow maybe have them tested with a tester or looked at by a electrician.

But if you are plugging them into some kind of power bar / surge protector then do try them directly to the wall and see if that helps.

90% of the homes I had lived in have had crap power installations, Way too many outlets on the same breaker or missing grounds so on which is why I always end up redoing them or installing separate outlets on their own breakers for my gear like my PC's and TV's.

Just my 2 cents. I went from terrible charging rates like those describes 3% per hour up to how it should be so hope this helps some of you.

Having to RMA my n7 would have been a real bummer. Especially if it would have been for nothing.

To add one last thing to my long winded post. Don't even bother trying to charge it via any kind of USB port on your computer its so slow you might as well have it on a hamster wheel with a dynamo. You really do need a real charger or the wait is unbearable.