We've all been there: going out to your car in the morning only to find that your battery is dead. However, what many people often blame on the battery can actually be the fault of a number of other automotive parts, such as the alternator. It's important for drivers to know exactly how these systems work if they plan on maintaining their vehicle.
The alternator essentially provides the power to the battery. As the engine runs, it rotates a crankshaft, which generates power that is then stored in the alternator. From there, the electricity travels to the battery, which then supplies energy to the rest of the vehicle. Thus if your car is dead in the morning, it doesn't solely mean that your battery is the issue - it's possible you also have a bad alternator.
A bad alternator can be caused by a multitude of problems, according to eHow. These vehicle parts are very susceptible to high heat, for instance. They can also suffer from diode failure over time, which will eventually cause your battery to drain.
Mechanics should be able to spot a bad alternator when they provide diagnostics during vehicle inspections. However, if you'd like to check for yourself, you can try revving the engine while the car is parked. If the headlights dim or brighten based on the engine, it's possible your alternator is faulty.