Re: Nexus 7 1A charging issue???
Would this be a travel charger by any chance?
Whatever it is it was supplying a minute current. The N7 will charge from 500mA (standard USB), but the screen has to be off (that panel takes some juice). The proper charger can supply 4 times this current (2 amps), which will charge the tablet whilst it's being used. Most tablets are like this, the screens just use too much power for the 500mA USB limit.
As soon a USB socket can supply over the 500mA standard, it has to tell the device it is capable of it (otherwise the device would just try to pull too much from the socket and cause the PC's USB controller to shut down the USB port as protection). This is usually done by linking the two data wires together (a charger has no use for these anyway).
If your charger doesn't link them, the tablet won't know if can suck harder.
From what you say it sounds like your charger was even worse than outlined above. It is probably badly regulated and maybe dangerous. A friend has some knock off Chinese Apple-esque chargers which my N7 just ignores. Won't charge at all, although both his and my phones will. I checked one out on my 'scope when it was charging my phone and the quality of the supplied power was horrendous. Smooth was not a word I would use. It looked like a the mad scribblings off a deranged fanboy who queued for three days only to have the stock run out as he reaches the front of the queue.