[myself6]

The cost to charge the battery doesn't change if the battery is charging or not. The cost is paid when the belt turns the pulley that is connected to the rod that holds the windings of conductor.

Once turning, the alternator generates an electrical current. No matter the electrical load you place on the alternator the engine will NOT work harder. If the electrical load becomes to much for the alternator things will simply stop working. but the cost to run that specific alternator will not change (barring wear and tear on the bearings and sh-t like that)

[coloradan]

Again, you are mistaken. Very mistaken.

[webstersII]

"No matter the electrical load you place on the alternator the engine will NOT work harder. "

You are completely mistaken. Study some stuff about electrical motors and you will quickly find out.

A simple experiment will prove it, also. Go out to your car and start it, leave it idling in Park. Turn the headlights on and off, noting the change in load on the engine.

Headlights take a significant amount of current and on some cars it's really noticeable when the current draw increases.

[FastCoyote]

"Once turning, the alternator generates an electrical current. No matter the electrical load you place on the alternator the engine will NOT work harder. If the electrical load becomes to much for the alternator things will simply stop working. but the cost to run that specific alternator will not change (barring wear and tear on the bearings and sh-t like that)"

Now that is one ignint statement.