HHR Possible Alternator?

I was driving home from work today, and after i went to Burger King for a Whopper meal (Healthy i know), my traction control and stability light came on. also, my radio cut off. this only happened when i let off the gas. I was pretty close to home, so i was able to make it there. But as i got closer, the power steering started to go out too, with the message displaying on the dash to check the Power steering system. The only odd thing was that all these symptoms went away when i pressed on the gas.
A few weeks ago i did notice a whining sound coming from the engine and i did suspect the alternator. after i turned it off, i checked the voltage on the battery and it read a bit over 11 volts. the car wouldnt start and the lights were dim. I hooked my wifes car to it and it fired right up and stayed on until i turned it off.
I dont know much about this car becuase i just got it in feb, and it made a trip from Ohio to Gatlinburg with no issues. Any info will be greatly appreciated.

11 is too low. But serpentine belt may be slipping. You didn't post the year.
How old is the battery?

Put that DVM you have on the battery terminals with engine purring....if it reads less than battery volta (around 12.65) then yes, alternator is caput. A healthy alternator reads around 14 volts or higher.

11 is too low. But serpentine belt may be slipping. You didn't post the year.
How old is the battery?

Sorry about that. Its a 2007.

Put that DVM you have on the battery terminals with engine purring....if it reads less than battery volta (around 12.65) then yes, alternator is caput. A healthy alternator reads around 14 volts or higher.

Yea, I put the DVM on there while running, it was about 12.3 then jumped to 13 when I pressed on the gas. I'm replacing the Alternator and the belt tomorrow.