hp laptop squeaking noise when battery charging

[ashmal]

around 3-4 months ago my laptop (HP G72) started making a continuous squeaking noise when the battery was in charging. It only squeaks when the charge level of the battery is at a low percentage around under 40%. It still squeaks when the laptop is off. I just ordered a brand new genuine hp part battery and it still does the same thing. The noise isn't coming from the charger. Its coming from around the area just above the middle of the battery.
any ideas what the problem is?

 

[digitaldoc]

Is the sound coming when the laptop is moved, or just sitting there?

The sound, as it seems to be present when charging, may be related to the power supply.