janedoesmith did a bunch of testing with different charger and cable combinations. http://forum.xda-developers.com/show...4#post29983624
Sounds like the most common problem is just cables with micro USB connectors that are too short.
There are a handful of threads that are a mish mash of good and bad/non-information. The N7 charger situation is a mess and finding a charger that works well is
almost impossible. It seems the cable you use is important, too.
"Confirmed working" chargers are chargers that work at > 500mA
Confirmed working 3rd party charger/cable combos (Updated 7/30/12):
- OEM Asus charger / $25 / ~1.8A / 3' cable
- HP Touchpad charger / ~$15 / ~1.6A / 6' cable
- Blackberry 1.8A Playbook charger / 1.8A rated / $15 / 6' cable
- Asus Transformer charger model AD827M / $? / 2A / length?
- Nokia AC-10U / 1.2A / $? / 6ft integrated cable
- Blackberry 700mA charger / 700mA rated / $5 / 6' cable
airphoto has noticed the actual micro usb connector is a little longer on the OEM cable than a typical cable. This is the only confirmed physical difference we know about at the moment.
Here is my experience:
- Chargers seem to work in 3 different ways: 1) they'll charge at full capacity, 2) they'll charge but slower than they are rated, or 3) they won't charge at all (and the N7 will NOT show a charging icon) (Update: Chargers that don't show a charging icon will actually trickle charge, roughly 5% an hour)
- Shorting the data pins on a charger that doesn't charge at all (#3 above) results in NO CHANGE
- The USB cable you use is important, in what way I'm not sure. Using a cheapo cable I have with the OEM 2A charger results in my N7 charging slow, probably 350ma.
And here are the chargers I've tried with results:
- OEM charger with OEM cable: Charges from 0-100% in about 3 hours
- OEM charger with cheap cable: Charges from 0-100% in 18 hours or worse if the screen is off, drains FASTER than it charges with screen on
- Blackberry 700ma charger (integrated cable): Charges from 0-100% in about 8 hours, which is in line with what you would expect with it's output
- Cellet 1000ma charger with any cable: will not charge at all
- Cellet 1000ma charger with data pins shorted: will not charge at all
- Motorola dual charger (Razr Maxx): Same slow charge as above, about 18 hours to charge fully
In addition, I've used a handful of different brands and types of generic cables. Something is different about the OEM charger but no one (AFAIK) has been able to identify it yet. There is clearly more at play here than the rated charge rate, so if that is your only comment, please keep it out of this thread.