MacBook Pro 2011 Battery Re-Charging Issue

Question

Hey everyone, I discovered a problem on my 2011 MBP 17" which I was told that "it's perfectly normal' and I want to see if you guys can reproduce it on your new 2011 models as well (please indicate your screen size).
In summary, I noticed that depending on CPU usage, the battery reacharge time will greatly fluctuate to the point where the laptop just stops charging the battery. I noticed the giant fluctuations in time when I booted one of my VMs which used up like 15-20% overall cpu usage. I was at 5% battery life and the computer was plugged in recharging and the battery indicator all of the sudden went from somewhere around 2.5 hours recharge time to 10 hours to 15 then 20 hours. Then at some point the magsafe light went green and the battery indicator showed 'Not Charging'.
I thought that I may have a bad MagSafe so I tried the one from my 2009 MBP (both are the 85W version) and bam same problem. I figured that this may be due to a design flaw where the power unit cannot supply enough tower to feed a CPU that's being somewhat taxed (i'm talking about 25-50% usuage) and recharge a battery.
Here is a simple way to try to reproduce the problem:
1. Let you battery drain to about 80% or less.
2. Close all open programs.
3. Change your battery indicator icon in the menu bar to display the info as 'Time'.
4. Plug in your MagSafe and let the recharge time in the battery indicator calculate and stabilize (give it about 2 mins to get a stable time value).
5. Open up safari and go to Hulu and play any TV show to drive up your cpu usage.
6. Then open Terminal and type the command 'yes' (without the quotes) and hit enter. The 'yes' command basically causes an infinite loop of the letter 'y' to be display in the terminal window which also taxes your CPU in addition to the video playing in Hulu.
7. Now watch the battery indicator's recharge time value and you should notice that it'll start going up significantly in time and at some point it'll say 'Recalculating' and eventually it'll give up and say 'Not Charging'. I have a 2009 MBP 17" C2D 2.66GHz, and although the recharge time goes up by 20-30% in the exact same test, it at least still charges the battery.
I was able to reproduce this at the apple store on a 17" 2011 model as well but I'm curious if this also happens on the 15 and 13 inch models. I was told by the engineering team on the phone that this is 'perfectly normal'. I guess it falls in the category of malfunctions as designed...
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Answer 1

TheRosta, jkirker and zapatillo: Everything you report is normal. Under heavy load, more power is delivered to the CPU/GPU/other hardware and less to the battery charging circuitry. Under very heavy load, all power goes to the processors and none to the battery, and under extreme loads, power is drawn from the battery to supplement what is provided by the AC adapter. All of this is by design.
You might well ask why Apple didn't just provide a more powerful AC adapter. I don't know Apple's reason(s), of course, but one possible explanation is that the machine couldn't dissipate the additional heat that would be generated by feeding 20, 30 or 50 more watts into it. If that's the case, then maybe the present 85W adapter is the best compromise Apple could devise between providing sufficient power and managing heat effectively, without completely redesigning and enlarging the MBP case to accommodate bigger fans and heat sinks and more air circulation space.