Once the car battery is completely charged, where does the extra output from a car’s alternator go?

Question

I realize there are sophisticated computer controls in today’s automobiles, so let’s keep it simple and use an old Jeep CJ as an example. The thing sometimes powers the lights, wipers, water pumps, radio and charges the battery, but once the battery is completely charged, and all those accessories are turned off, the alternator is still churning out the same output. Where does it go?

In: 4

Answer 1

Electric only goes where it’s needed, if there’s no load it isn’t generated at all, just a spinning rotor. The more demand put on it, the more it will generate using more of the engines power to drive it, up to the 500 watts or so the alternator can output.