Can a battery of a diesel car be charged by another battery of a petrol car?

Answer

Dear,

Charging is always allowed, but a correct approach is of great importance. You connect the jumper cables with respect for the polarity. Then start the petrol car. Let it charge the battery of the diesel car. Then stop the petrol car but leave the jumper cables connected. Then you start the diesel car.

If you follow this order, nothing can happen. You should certainly never start one car while the engine of the other is running. In that case, the risk of serious electronic damage is high.

Good luck

Mark