When a vehicle ships from the factory, it comes with an alternator that meets the basic needs of a car’s electrical systems. Although there is some wiggle room with the factory charging system, the addition of speakers, subwoofers, infotainment systems, and other energy-draining components can result in dim headlights, poor audio performance, and other problems. The solution to install a high output alternator.

Although there are a few ways to deal with a shortage of power (including additional batteries and stiffening capacitors), a high output alternator is the only way to address the problem at the source. These high-powered units put out higher amperages than factory alternators and are available from aftermarket manufacturers, rebuilders, and OEMs.

What Qualifies as a High Output Alternator?

Since factory alternators aren’t uniform in terms of power output, the term high output alternator is going to be relative to the original amperage rating of a vehicle. To qualify as a high output unit, an alternator needs to provide more amperage than the factory unit that it replaced. That means there is a big difference between a series wound unit that provides 130A and a hairpin unit that provides upwards of 370A. There’s also a difference between simple re-winds and units that are manufactured from new components.

Who Needs a High Output Alternator?

Stock units are designed to meet the needs of the electrical systems on the vehicles that the units ship with. Because most people don’t make significant modifications to their vehicles, most drivers won’t need a high output alternator. So, how can you tell if you need to replace a factory alternator with a higher-powered aftermarket unit?

One sure sign that an alternator is underpowered for its application is if it burns out too fast. If you go through alternators on a regular basis, your unit is probably running right up against the ragged edge at all times, which can cause undue wear.

Even if your vehicle is more or less stock, install a high output replacement alternator if you are in the shop for electrical problems regularly. Since some vehicles ship with multiple alternator configurations, you may be able to find a direct-fit, original equipment replacement unit.