ECN Forum Forums Technical Discussion Electrical Theory and Applications Switching adapter for laptop interfering with mic

That power supply you have for your laptop is faulty.
There should be no AC ripple at all at the terminals where it connects to the laptop.
This alone, will affect the way your battery is being charged.
Batteries require VERY smooth DC with a minimal amount of AC ripple.
My advice would be to send it back under warranty, as it is not doing it's basic function.