That's cool....if that's the case it would move the nexus a little higher on my list. Be curious if it can charge fast enough. The xoom luckily enough has a 1.5A charging port so I can't drain it faster then it charges....
The MHL adapter I have does require some power - it doesn't work without the charge port connected to something which does kind of change the idea that the tablet has better battery life since you'll need power for the phone at all times.
When my phone was down to <15% I tried it out with a 700mA charger and the HDMI kept dropping out and the phone was still losing charge. I let it charge and dug up a cheap 1A charger (I wouldn't be surprised if it put out less than that). I then started a TV show on NetFlix (WiFi) at 26% battery, 45 minutes later I was at 28% so I was at least able to hold my own.
Note that empty batteries can pull more power than nearly full batteries, on marginal chargers my X can maintain charge with no problem under heavy usage. But at <50% charge I needed to power everything off to charge or just turning the screen on would cause the charger to turn itself off.
In summary, it seems that with
this MHL adapter and a random 1A charger you can watch movies indefinitely, but it is possible that even with a 700mA charger you can do this on a full battery.
Hope this helps, let me know if you'd like any more details or experiments.
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