Originally Posted by Entropy512

It's listed as an iPad charger so this isn't surprising.

See above - iPad chargers are not detected by any Android device I'm aware of as a proper charger.

I can charge my Nexus One, HTC G2 and Galaxy Nexus using both the PlugBug and the iPad charging adapter. They just won't work with the N7.

http://forum.xda-developers.com/show...4#post29983624

The charger for the BB 9300/9800/9900 work. The ones I have for my iPad's don't. None of my car chargers work either Will have to resort to using an inverter in the car, i guess.

Originally Posted by teufeldog

I can charge my Nexus One, HTC G2 and Galaxy Nexus using both the PlugBug and the iPad charging adapter. They just won't work with the N7.

They are charging at reduced current (<500 mA) as most such devices assume a PC USB host or "misc" charger when they see iDevice voltages on the data lines.

Samsung Galaxy S and S2 series devices charge in USB mode when an iCharger is connected.

Samsung Galaxy Tab series devices refuse to charge over USB, and hence won't charge when an iCharger is connected. (They, like the N7, may charge slowly without reporting charging.)

The Nexus 7 seems to have some additional methods for differentiating between "misc" and USB - If it does not enumerate with a PC host, it assumes "misc" and refuses to charge unless D+ and D- are shorted (which indicates a "dumb" charger).

Nearly all chargers in my possession have D+ and D- shorted, and the N7 happily charges from all that I've tested so far.

best not to use cheapo chargers that put out dodgey ripple and voltage specs, always use a good quality charger than a cheapo high amperage charger.
i phone charger i can confirm works, but its slower than oem charger.

also last night i had the nexus7 on charge with my computer, from 27% when i put it on charge to the morning about 7 hours of charge time it showed 44% charged,
i was using a 1.5meter usb extension cable and then the oem cable attached ot the extension cable.
as you can see the charge was too slow. pc has gigabyte p35t-dq6 mobo and corsair hx620 psu.

need to see if i can get a proper high quality 3 amp charger. the oem one does tend to get a bit warm, but then again so does the iphone charger i have.

with 1.2a nokia charger, n7 charges up as fast as oem. n7 doesn't need 2a. it just needs to have the shorted charging cable.

Won't work with apple stuff

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My experience is that with any charger designed for an apple product won't charge the Nexus. I've installed the Nexus is my car dash and have been trying to find a good dc adapter.

I took two different adapters, one had both ports set for apple, the other had one. The one non apple would charge slow. Only after I removed the resistors on the data lines and shorted them together would the apple ports charge the Nexus at all.

I put a meter in series with the wiring to test the current. They say their rated at 2A, but the most I saw was 600ma. Typically, it was running at 575ma and the Nexus indicated AC and it was charging at that rate, though slowly.

I had both wifi, BT, and was running a video and got the same results. This was using a cheap, generic cable (I need a right angle micro plug for it to fit where I mounted it).

Still don't know what the answer is...

Originally Posted by joed1ver

My experience is that with any charger designed for an apple product won't charge the Nexus. I've installed the Nexus is my car dash and have been trying to find a good dc adapter.

I took two different adapters, one had both ports set for apple, the other had one. The one non apple would charge slow. Only after I removed the resistors on the data lines and shorted them together would the apple ports charge the Nexus at all.

I put a meter in series with the wiring to test the current. They say their rated at 2A, but the most I saw was 600ma. Typically, it was running at 575ma and the Nexus indicated AC and it was charging at that rate, though slowly.

I had both wifi, BT, and was running a video and got the same results. This was using a cheap, generic cable (I need a right angle micro plug for it to fit where I mounted it).

Still don't know what the answer is...

The datasheet for our charger chip (Summit SMB347) indicates that it has a feature to automatically limit current if input voltage drops (for more universal charger compatibility, since it's impossible to determine exactly how much a given DCP is rated for).

It seems that it is set in the N7 to be pretty aggressive - Long cables will reduce the current, and I think there's a good chance that the resistance of the ammeter, while small, is enough to cause a voltage drop.

Can you try CurrentWidget with http://review.cyanogenmod.com/#/c/20891/ instead, and put the meter in parallel to measure the charger voltage when charging? I wasn't able to get out the door in time today to get to the electronics store and buy a cable to cannibalize and some banana plugs.

My observations:
Tab 10.1 charger reports 1400+ mA charge current in CurrentWidget
Stock charger reports 1200 mA or so
A modified Scosche iPad car charger only does 600-800

It seems like many iPad chargers may not be meeting their rated specs...

Entropy512:

I'll check it out in the morning and post my results.

Some more charging results.

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Current Widget gives me "No Data", however I am certain my testing procedures insert very little error into the readings.

I also was running Battery Meter Pro, but it's estimates were off by double.

With a generic 1A/2A dc adapter using the original cable from my Nexus, and the battery level at 87%, I was getting about 840ma @ 5.33v

Using a Startech 3' w/ right angle micro I was getting 620ma @ 5.33v.

Using a generic 6' cable from Altex I was getting 530ma @ 5.33v.

I used two different but similar adapters and got the same basic readings.

These readings were taken one after another twice with the same results.

The Startech cable is probably using smaller gauge wire due to it's diameter, but the generic cable appears to be the same as the original, though it's longer.

Cables matter.