battery life - Nexus 7 charges very slowly, even with 2 amp chargers

I'm facing a rather painful issue with the battery life/charging issue with my Nexus 7 (4.2.2)

• When idle and plugged into my 2A charger with the stock USB cable, it charges VERY slowly. I'd say under 10% per hour.


• With just light usage over the course of an afternoon/evening, the charge got dropped to 50% (after charging it overnight and more).

I'm sure that something is wrong because no tablet should be performing that way (comparing to my other tablet, an iPad)

Update: I plugged my iPad1, iPhone5 and Nexus 7 into the same port on my Macbook Pro Retina. I've added a (mashed up) screenshot of all the 3 cases below and it's clear that the Nexus 7 never even demands anything above 500mA on a 2A port despite using the stock cable (and another microUSB cable). I'm now guessing this is a Nexus 7 firmware/software issue. Any fixes? That extra operating current should be 1600mA so it totals to 2.1A (="2A" ports).

Full resolution screenshot

Details:

• Android v4.2.2 (stock image)


• Settings => Battery
  
  
  
  
  • Screen (77%)
  
  
  • Android OS (6%)
  
  
  • Tablet idle (6%)
  
  
  • WiFi (5%)
  
  
  • Maps (4%) (Maps isn't even running ... weird!)
  
  
  • Android System (2%)
  
  
  
  

I mostly use Chrome, Currents and Play Magazines so it's just light reading. I'm surprised those apps don't show up on the battery energy audit list (which is great compared to iOS BTW).

Question: What can I do to charge this device faster and use less battery? My expectations are anchored by my other tablet (an iPad) which charges a lot faster (2A charger again) and uses about 20% each day for casual reading vs 50% each day on the Nexus 7.

Answer

Not necessarily an answer but I ended up using the stock charger that came with the Nexus 7 itself. I leave it plugged overnight. None of my other "2A" chargers can charge it quickly nor can my computers. This sucks because now I have only a single rapid charging station, next to my bed (vs my office, my living room etc). Standard protocol or not for charging, this kills my user experience compared to how my iPad just works without a headache.

For battery consumption issues, I disabled auto-update in Google Play as well as disabled auto-update in Google Currents and Google Magazine. Seems they were downloading a lot of data in the background killing my battery life.

Anyways, now that I tinkered with it the overall experience is much better.