Yellow Bullet Forums banner
1 - 20 of 23 Posts

· draggin' ass
13,416 Posts
What kind are they? Im sure their worth some horse power.

· Registered
8,263 Posts
If it put out full amperage at all times, it'd cook your battery and itself in short order.

An alternator uses a constant current/constant voltage charging scheme.

It brings the system voltage up to ~13.5 volts and puts out whatever amperage the battery will absorb until it's full again, while providing power to whatever electrical component draw the system might have.

It's the alternator's job to provide enough electrical energy to run the car. It's the battery's to simply have enough power to start the car and provide enough energy to keep the car's computer's memory when the motor isn't running.

If the only draw on the alternator is say the tail lights, it's only going to drag off enough energy to supply that one amp.

If, however, the alternator is powering the ignition, the water pump (if electric), the fans (if electric), fuel pump (if electric), lights, trans brake, data logger, etc etc etc, then yeah, the load on the alternator is going to be significantly higher and it will pull more power from the crankshaft.

This is another reason you NEVER want to take a totally dead battery, jump it, and then let the alternator charge it up. Running an alternator in full load condition for a long time will cause it to burn out.

You also never want to size your alternator to the same size as your current draw. If you draw 60A worth of current, you want an alternator capable of 100A to 120A. Doing this will allow the alternator to run at increased efficiency, and it won't be taxed, thus shortening it's life span.
1 - 20 of 23 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.