* Starting the Engine: A car's starter motor relies on the battery to supply the high electrical current needed to crank the engine and start it. Without a battery, the engine cannot be started by the usual means. However, some vehicles (particularly older models with manual transmissions) might be able to be push-started or jump-started without a battery in specific circumstances.
* Electrical Systems: Many of the essential electrical systems in a modern car require battery power to function. This includes everything from the ignition system to the fuel injection system, lights, wipers, radio, and more. Without a battery, these electrical components will not have power, affecting the car's overall functionality and making it impractical for everyday use.
* Charging System: In a normal running car, the alternator recharges the battery while the engine is running. However, with a dead or absent battery, the alternator's output voltage will have nowhere to go and can potentially damage electrical components due to voltage spikes.
Even if a car could be successfully started without a battery, the electrical issues mentioned above would cause numerous malfunctions and potentially damage sensitive electronic components in the vehicle. Therefore, while a car might be started under special circumstances without a battery, it cannot be run effectively or reliably in modern vehicles without one.
