Interference when playing and charging

Hey - I am using this unit in my car and plugging into the stereo via a speaker cable.    All works fine and sounds great, but then you plug it into usb charger and there is a lot of interference noise coming through.

I hae tried various difference charges and even little stand alone portable chargers to see if the cable/charging unit was causing this but it is happening with everything.

I have changed usb cables as well.

If i plug in my ipod via the same connector it is fine.


Are you using a power only USB cable? Or perhaps try using a shorter usb cable that has two chokes on it?