Last Updated: 05.11.2021

Back in the first few years of the motor car the need for a battery meant the need for something to charge the battery, as well as supply current for the ever growing amount of electrical components — the Generator.

As the motor car evolved along with it so did the electrical systems. The generator soon proved inadequate with the extra demand so the modern day alternator was introduced to provide the extra grunt needed for today’s systems.

Alternators are able to produce high output and don’t require cutout relays current regulators. The Alternator diodes prevent the current from flowing back into it from the battery and the magnetic fields created around each stator winding control the current output of the Alternator.

The Charging system has 3 major components.

  • Battery
  • Alternator
  • Regulator

This Alternator works with the battery to supply power when the vehicle is running.

The output of an Alternator is Direct Current (DC) however AC (Alternating Current) voltage is actually created and converted to DC on its way to the battery and other electrical loads.


warning Don’t condemn the Alternator for a “No Charge” condition prior to carrying out these checks.
  • Lose, missing or worn drive belt.
  • Loose or Dirty Connections
  • Does the warning light glow with the ignition switched on?
  • Check all fuseable links and fuses.
  • Check voltage at the B+ terminal as well as the battery terminal.

Related: How Much Does It Cost to Replace an Alternator?