About Our Alternators

Important Information

If you attempt to run a new high amperage alternator with a stock battery, this could cause voltage drop which will negatively impact the amount of voltage delivered by the alternator. Please be sure to have a strong battery, a good ground, proper wiring, and the correct size belt. We recommend the “Big 3” upgrade, and a smaller belt because each alternator comes with an overdrive pulley which is smaller than the factory pulley.

For a chart of almost all belt part numbers, you can use the following link below.

Simply find your factory belts part number, and generally the next size down will work perfect.

If you need us to find the right belt size for you, just let us know and we can send it over for your convenience.

Click to access LD-HD-BLT-DIMGUIDE-1019_Auto-and-HD-Dim-and-ID-Guide.pdf

Hairpin Technology

We utilize only the most reliable technology in our alternators at any cost. Going the extra mile is what we specialize in. Whether your vehicle is old or new, we try to get small or large case hairpin options for your vehicle, instead of just building a slot wound style like the competition. Some benefits of this approach are:

  • Diodes:
    • 60 Amp diodes in small case instead of 25 amp diodes in small case and large case.
    • Large case hairpins also have the option for 100 Amp diodes to be utilized.
    • 12 diodes in hairpin, instead of 6 diodes like conventional.
  • Rectifiers:
    • Dual bridge rectifier instead of single bridge, allowing for even more efficient cooling. Finned rectifier in large cases, for even stronger durability and cooling. This will benefit your daily driver as well.
  • Stators:
    • Our hairpin stators are hand soldered and welded in house, using OEM stators instead of Chinese stators, again helping long term reliability perfect for a daily driver.
  • All of our small and large case stators are 6 Phase, instead of 3 Phase.
  • The windings are also not stacked on top of each other like slot-wound. Rather, the windings are segment conductor/hairpin – which is square wire laid flat as a lamination stack. The segments are welded or soldered into other segments in two different phase combinations – WYE or Delta Phased.


We are focused on using only the best parts for your vehicle, and although many vehicles do not have hairpin alternators as OE, we have found ways to machine and custom CNC cut brackets to match your exact mounting bracket measurements to allow our alternators to fit, while also allowing the best hairpin tech to be utilized in your alternator for ultimate reliability. We have spent thousands of hours coming up with the best designs on the market to allow for this. Some design elements include milling out of OEM housings to fit the new stator/rotor, CNC cut ears/mounts to allow it to bolt up exactly like a stock alternator, and custom 3D printed plugs to allow a plug and play install.  Changing your factory slot wound to hairpin technology also allows us to build almost any vehicles alternator for 220-500 amps depending on the vehicle.

Big 3 Upgrade

Although not required, we highly recommend doing “The Big 3” upgrade before installation of a high output alternator, here’s why. The “Big 3” upgrade in car audio refers to the process of upgrading the three main electrical cables in a vehicle’s electrical system. These cables are:

  1. The power cable: This is the cable that connects the vehicle’s battery to the alternator, which charges the battery and powers the vehicle’s electrical system.
  2. The ground cable: This cable provides a direct path for electrical current to flow back to the battery. It is important to have a good ground connection in order to ensure that the electrical system operates efficiently and reliably.
  3. The engine block ground: This is a separate ground connection that is often overlooked but is also important. It provides a direct path for electrical current to flow from the alternator to the battery and ensures that the electrical system operates properly.

Upgrading these cables can improve the performance of a car’s audio system by ensuring that it has a consistent and reliable source of power. This can help to reduce noise and improve the overall sound quality of the system. It can also help to reduce strain on the vehicle’s electrical system, which can extend the life of the battery and alternator. Overall, the Big 3 upgrade is a popular modification among car audio enthusiasts who want to get the most out of their audio systems.

Computer Bypass Plugs/Extension Harnesses

Here at Apex Alternators, we truly go the extra mile for the best performance possible for your electrical/audio system. Often, vehicles will control your voltage through the computer. Often times resulting in your vehicle actually shutting the alternator off until certain accessories are turned on, such as head lights/A.C. – this can be a common result of this. We understand this can be a big inconvenience, and have made hundreds of different extension plug harnesses that allow us to bypass the factory computer control, and give you a strong, healthy 14.8V set-point which will not be lowered by your computer. Doing this requires us to use a different plug than your OEM alternator, but we’ve done it here so you don’t have to! We have made these adapter harnesses to plug in from the alternator, to your factory plug with no cutting, splicing, or hard-wiring your factory harness. You’ll no longer have to worry about your computer putting a lower set-point on your system, which also keeps the computer from shutting off your alternator. Although this is a great solution for your vehicle, it can turn a battery light or error code on, and we will let you know if that would happen on your vehicle. This is a rare occurrence, but can happen on certain vehicles.

Booster Harnesses

For those of you running lithium, such as LTO Cells, we have made booster harnesses that allow varying voltage set-points ranging from 15.3V to 15.8V. This WILL require a GM plug to be on your alternator with the “P L F S” Pin Code. We sell the regulator and the booster harness pigtail with the diode already soldered in-line on the Sense Lead. Please email us for availability! Prices start at $45.99 shipped! We will only have this option for Hairpin Style alternators.

Options for this harness include:

  • 15.3V – 15.5V
  • 15.5V solid
  • 15.6V – 15.8V

Don’t worry, they’ll fit

Every alternator you’re quoted is a direct bolt-on, which means it will always bolt on exactly like your factory alternator because we build each in the factory style housings, and it will also plug right into the factory harness. If your stock alternator can interchange with one of our hairpin style alternators you’ll be quoted for it. We will let you know the pricing for the factory style alternator, the replacement hairpin style alternator, and the amperage differences to be sure you get exactly what you’re looking for.