If you need to replace your auto battery, always test it before you replace it. Also test the entire electrical system of your car. The reason for your battery problem might be a weak alternator or a drain on the system and if this is the case it won't take many weeks before your have to replace the new one as well. What seems to be a battery problem is not always caused by the battery itself. You can acquire more information about how to repair your car's electrical system on the web.
Starter: starting the car was a sweat-breaking business before the starter. A procedure by it's own, where you had to be fairly skilled. Cranking the car was done with a cranking rod. The driver would put it into place, use all the strength available, crank the engine and if he's lucky the engine would start after a few turns. If not, he was in for another lesson in body-building. Aside that, when the engine started the driver had to let loose of the rod in time or else he would get a knock in the face. Every time you put the key into the ignition, remember this and enjoy it as a privilege.
If the car's dashboard battery light comes on, you might be able to make it home or to a service facility for a repair. The car will continue running as long as some juice is left in the battery, but if the charging system isn't working or you have a bad alternator, your car's engine will stop running once the battery is drained. If you turn off the engine, you won't be able to restart it if the battery doesn't have enough charge left to power the engine's starter motor.
Vehicle charging systems haven't changed much over the last few decades. But with the increasing complexity of the modern automobile, along with the addition of many aftermarket accessories such as cell phones, DVD players, high-power audio systems, alarms etc., the role of the charging system is now more important than ever. The charging system on your vehicle can be thought of as a small power plant which does exactly what its name implies - charges and maintains a good state of charge on the battery.