Car Battery Replacement

[allblack]

I had my car battery replaced by a battery shop the other day.

I was a bit surprised that he removed the old battery while the engine was running and then put in the new one.

I read somewhere that doing so may damage some electronic circuit/components in the car.

Any experts here to shed some lights on this?

Cheers

I'm curious, what type of car and the name of the company that did the battery?