High Output Alternators & The Big 3

Proper amperage is key to a good electrical system.  A High output alternator may be your next step in your car audio journey.

Alternators are used in modern automobiles to charge the battery and to power the electrical system when its engine is running. Until the 1960s, automobiles used DC dynamo generators with commutators. With the availability of affordable silicon diode rectifiers, alternators were used instead. This was encouraged by the increasing electrical power required for cars in this period, with increasing loads from larger headlamps, electric wipers, heated rear windows and other accessories.

Older automobiles with minimal lighting may have had an alternator capable of producing only 30 Amps. Typical passenger car and light truck alternators are rated around 50–70 A, though higher ratings are becoming more common, especially as there is more load on the vehicle’s electrical system with air conditioning, electric power steering and other electrical systems. Very large alternators used on buses, heavy equipment or emergency vehicles may produce 300 A. Semi-trucks usually have alternators which output 140 A. Very large alternators may be water-cooled or oil-cooled.

If using multiple alternators you may need an alternator bracket.  Good practice is to upgrade to the “Big 3” when installing your new alternator.  The BIG 3 may sound intimidating but it breaks down to a few steps.

As always we recommend you consult a professional before you begin.

Start with a good wire, we recommend using 1/0 Gauge OFC Power and Ground Wire with anything electrical.  Better to start with a good connection rather than having to pull and re-run wiring every time you upgrade.  Save up and just start right from the beginning.  You will also need a few Ring Terminals/lugs.

When adding any grounds to your electrical be sure to pick a good position and prep properly to ensure a good connection.

  1. The first connection will be adding wire to connect your High output alternator mount/bracket to the body/frame of your car
  2. then connect you engine block to the car body/frame
  3. finally, connect the battery to the car body/frame.

For more check out this video from Sonic Electronix

Find the right balance between quality and budget.  Buying products that are cheap and not quality could result in replacement and expenses in the future.  Best Practice is to start right and not have to do anything twice.

This article uses material from the Wikipedia article Alternator (automotive) which is released under the Creative Commons Attribution-ShareAlike 3.0 Unported License (view authors).