M520 Car Charger beeping

Did a search but this phone is new, when I plug in a car charger the phone makes beeping noise. Anyone recognize this?

I don't know about it but my friend told about this experience, may be this happens.

Have you figured out the "beeping" problem with the car charger yet ? I tried two different car chargers and still have the same problem. It also seems that while this "beeping" is goiong on, the phone is not charging....Apparently, the sound is the same sound the phone makes when you plug in, or unplug the charger. It seems to me that it is constantly disconnecting and reconnecting itself. If anyone has any solution to this problem, PLEASE let us know...