Why petrol engine can start without battery but diesel engine cannot be started with same conditions?
Diesel engine can be started in that manner, but it would be more difficult unless the engine was already warm. Diesel engines use glow plugs to pre-heat the combustion chambers when the engine is cold. Without electricity, there would be no power to the glow plugs to assist in starting. You can get a cold diesel engine to start without glow plugs, But it will take longer. Gasoline engines don’t need glow plugs because the fuel is ignited by spark plugs.
