Battery drains when connected to charger and phone is active

[Arlequinn]

I just bought my Galaxy S3 a few days ago. I am used to leaving my phone plugged into the charger when I know I'm going to be using the phone extensively so I don't drain the battery. I have never had a problem with this with any of my previous phones. Today I was using my S3 to do multiple things while connected to the charger and I was surprised to have the battery completely drain on me. I had set the phone down on my desk and was paying attention to my computer for about half an hour so I'm not sure exactly when it died, but it was completely dead. I had to wait 10-15 minutes before it even had enough charge to show me the low battery image.

I also notice that the led in the upper left that should show red when it's charging is flaky. Sometimes it will not be on at all, but I know it is charging because the battery charge has increased since the last time I checked the phone.

Is this normal or do I have a bad charger, battery or phone?

Thanks,

-- Arlequinn

 

[runtohell121]

It's normal if your task is a heavy cpu intensive task.

 

[Arlequinn]

Actually it was the charger. I used my husband's charger instead and had no problems. The battery didn't lose any charge while connected to his charger while I performed the same operations as I did previously plus I added playing music.
Thanks,
-- Arlequinn