When a vehicle leaves the factory, it comes with an alternator that meets the basic needs of the vehicle’s electrical systems. While there is some wiggle room in the factory charging system, adding speakers, subwoofers, infotainment systems and other energy-saving components may result in dim headlights, poor sound quality, and other problems. The decision to install a high power generator.
While there are several ways to deal with lack of electricity (including extra batteries and stiffness capacitors ), the only solution to this problem is a generator with a high output power. These powerful units have higher amperage than factory alternators and are available from aftermarket manufacturers, remanufacturers and OEMs.
What qualifies as a high power generator?
Because factory alternators are not uniform in terms of power output, the term «high output alternator» will refer to the vehicle’s original amperage. To be considered a high output device, the alternator must provide more current than the factory module it replaced. This means there is a big difference between a high output unit that delivers 100A at idle and a water cooled unit that delivers over 350A. There is also a difference between simple rewinds and aggregates that are rebuilt from scratch.
Why is the output power of the alternator not so high?
The first generators blew older dynamo generators out of the water in terms of producing raw amperage. However, the electrical systems they had to supply in the 1960s were nothing compared to the electrical systems of today. Many early factory alternators were capable of delivering up to 30A maximum, which is the amount that many modern production units beat at idle.
Today, a typical alternator in an average car or light truck can produce somewhere around 50-80 amps. However, there is variation from one application to another.
The amperage rating only refers to its power at 6000 rpm, so a 108 amp alternator can only put out 40 or 50 amps at idle.
Who needs a high power generator?
Stock units are designed to meet the needs of the electrical systems on the vehicles with which the units are shipped. Since most people don’t make major changes to their vehicles, most drivers won’t need a high wattage generator. So how can you tell if you need to replace your factory alternator with more powerful aftermarket equipment?
One sure sign that a generator is not strong enough for its application is if it burns out too quickly. If you run through alternators regularly, your unit is likely to be running right on a rough edge all the time, which can lead to excessive wear and tear.
Even if your car is more or less available, install high power spare generator, if you regularly go to the store for electrical problems. Since some vehicles come with multiple alternator configurations, you may be able to find an original replacement unit.
When enough is not enough
Although a car’s electrical system is quite complex, you can get a good idea of whether you need a high power generator by doing a few calculations. For example, power is determined by multiplying current by voltage, so an 80A alternator can produce: