Car Audio, Custom Fabrication, Mobile Electronics

LIS Audio How-To: Explaining “The Big 3 Upgrade”


Do I need a Capacitor to stop my voltage drops and keep my headlights from light dimming? There are many reasons why a vehicles lights could dim when the stereo is at full tilt. When this happens and there are aftermarket audio components installed, it is generally pretty easy to hear the music start to suffer when the voltage drops too low. Power Caps, as they are often referred to, are somewhat a thing of the past due to most amplifiers on the market having the proper onboard capacitance to handle its potential current draw. Adding a Power Cap is like putting a bandaid on a wound that needs surgery. If you don’t “need” to use a capacitor, then what is the answer..? Let’s break it down!

Having spent a great deal of time giving advice to people online that are looking to get more involved in car audio, one question I run into most commonly is, “What is the Big 3 Upgrade?” The answer is generally pretty simple, overall. In this blog I will explain what this upgrade consists of, the advantages it offers, and the specific variables to take into account when performing the upgrade. There are advanced capacitor’s on the market that are often referred to as “Ultra-capacitors” or “Super-capacitors”, and they are mostly used in larger audio systems that will have more than one battery, or a very powerful lithium battery. We won’t get into the details of extremely powerful SPL type builds in this article, but touch on low power to larger powered daily driven systems.

What is the Big 3 Upgrade?

Simply put, this vehicle modification includes upgrading three primary charging wires. These wires are; battery negative to chassis ground, engine to chassis ground, battery positive to alternator positive. The main idea is to add more potential current flow from the alternator to the battery, thus providing plenty of current to the entire vehicle so that every bit of power transferred from the alternator can be utilized. This in turn allows for the power the alternator transfers to be used by the newly installed aftermarket amplifier/s in the audio system as well as spread to the factory components.

A good general rule of thumb is that most vehicles factory electrical systems can take 1,000-1,500 Watts (or 120%, according to the Advanced MECP Guide) of additional power. This is dependent on the size of the engines alternator, the size of wire the factory charging system provides, and the vehicles battery storage capabilities. All vehicles will differ when it comes to the potential amperage the alternator may provide. Adding more conductive cross-sectional area is better for the entire electrical system overall, as it will allow for more flow of electricity to spread throughout the entire vehicle. If the vehicle has more than 10 years on the road, it isn’t a bad idea to check for electrical charging connections that may already have started to deteriorate.

You can see the full build in our LIS Audio Blog “’10 VW Passat 2nd, 2nd Amendment Signature Build.”

How does it work?

The alternator converts mechanical energy into electrical energy by utilizing the rotational force created by the engine combustion cycles. The electrical circuit flows through the alternator chassis to the engine block and then from the engine block through the wire connected to the vehicle chassis. From the vehicle chassis, it then flows through the battery via the negative battery terminal. Connecting the positive battery terminal to the positive alternator terminal completes the circuit. The wire in this circuit, provided by the manufacturer, tends to only pass the right amount of electricity for the factory components. Not too much more.

When we look at the factory wires installed in the charging system we will find many different sizes. Some vehicles may have tiny 10 Gauge wires while others may have nice big 0 Gauge wire runs throughout the charging circuit. Some vehicles may have the battery located on the same side of the engine as the alternator, making for a very short circuit path for the electricity to flow. Some vehicles batteries will be located in the trunk, or hatch area, making for a very long circuit pathway to the alternator up front, and back to the battery. The chassis maybe used to transfer the ground of the negative battery connection from the rear of the vehicle to the alternator in the front. Read more about wire size; wire material and chassis conductivity, in the LIS Audio blog “Choosing The Proper Wire”.

The benefits of “The Big 3 Upgrade” explained…

Alternating Current (AC) the alternator produces is turned into Direct Current (DC) through a formation of diodes which cause the rectification process. We tend to refer to the battery as “supply” as well. Most commonly the voltage of the battery while the vehicle is running at idle will show anywhere around 12.5-13.8 Volts. Once the big 3 upgrade is performed the voltage will tend to jump up to the 14.4-14.8 Volt range, and possibly higher. This will allow an aftermarket amplifier to be more efficient due to heightened overall voltage, which we will breakdown in this blog with a bit of math to show the difference.

A simple math equation to see how much of the total power the alternator may produce is Volts X Amps = Watts. This means if the vehicle idles at 12.8 Volts and the factory alternator is rated at 120 Amps, the alternator will produce approximately 1,536 Watts of potential output. After the Big 3 Upgrade the number could shoot up from 1,536 Watts to 1,728 Watts which means, an additional 192 Watts of overall power at idle just from upgrading the charging system wires to a larger size. This can come out to be an even greater difference when using a high output alternator. You can find more information on converting power measurements in the “Simple Science & Methodical Math” section of the “Choosing The Proper Wire” LIS Audio blog.

Check out the blog “LIS Audio March Feature – 1970 Custom Dodge Charger Build” to see this full build.

The example we use here is on a 2014 Toyota Tundra, keep in mind, results can vary greatly depending on the vehicle. This is just a simple way to show you the impacts of the charging system upgrade with one single application. The readings on the Digital Multi-meter were taken while the vehicle was running at idle. We can see in the “before” images the meter read approximately 13.78V at the battery while it read 13.06V at the amplifier. After the upgrade we can see the meter reads approximately 14.13V at the battery and 14.10V at the amplifier, which leads us to belief the electrical system may now have become a bit more efficient. With the system turned up to it’s maximum safe level we see the Voltage still sits higher than it did at idle prior to the upgrade. That’s a win!

See more details on this 2014 Tacoma stereo upgrade on our blog Benefits Of An Upgraded Audio System!

Many vehicles, old and new, may have the connection point of the alternator power wire to battery power running through the main starter terminal. On these vehicles the wires to the starter may also need to be upgraded to the same size as the newly added wires to the other parts o the charging system, to maintain proper current transfer for the start and charging process. It is crucial to know what to look for and which parts are necessary, like terminals distribution blocks and connectors, to add the new larger sized wires into the system.

Surface to surface contact is best for electrical conductivity. This means dirt, paint and primer should all be cleaned from the point of contact before installation of the new wire and mounting hardware to its new surface. This comes down to the simplicity of moving electrons and ions through one conductive material to another. At this point it is once again important to know the details about conductivity in the many metals used to transfer electrical energy, if you need to brush up read the “Choosing The Proper Wire” LIS Audio Blog. Knowing the proper installation techniques to ensure reliability is also very important.

What to expect…

Adding the Big 3 Upgrade can help reduce, if not eliminate, voltage drop and light dim while the vehicle is running at idle and the audio system is running at full tilt. There are many other variables that will come into play from vehicle to vehicle that require more attention, or possibly professional expertise. Some alternators will come externally regulated rather than internally regulated. Knowing the differences can be important for upgrading your charging system wires, so be sure to ask the alternator company or person performing the installation if there are any additional parts needed when upgrading the alternator.

If you’d like to learn more on this build check out “LIS Audio November Feature – DJ BigDad Build.”

“One final consideration about aftermarket electronics and their impact on a vehicle electrical system, particularly audio amplifiers, is that it’s often more rewarding to choose equipment and designs that work within the operating characteristics of the factory electrical system’s capacity rather than building something so big it needs one or more big aftermarket alternators just to keep it powered reliably.” –MECP Advanced Installation Study Guide

You can see the full build of this 350Z at “LIS Audio April Feature – 2 Part, Part 2.”

If you plan to go above and beyond the daily driving reliability when adding aftermarket amplifiers, be sure to plan on adding more batteries for power supply, a high output alternator and much more wire to transfer the electricity. Consult with a professional installation tech or the specialists that work with the alternator and battery companies which, you plan to purchase product from, to make sure you have all of the proper information to make educated purchases. There is much more planning and physics that will go into building a successful SPL competition setup so, be sure to plan well from the beginning to end of the build.

In conclusion…

As mentioned above it is crucial to have an experienced installer to perform this upgrade, add batteries, and properly identify the right alternator plugs and connections. Some vehicles will have batteries that are buried under other components making it hard to access, and similar to alternators their connection terminals. To help anyone that is new to upgrading a car audio system it could be very helpful to read up on what specifics to look for when planning the upgrades. Check out the LIS Audio blog “Properly Planning Your Sub-stage” to get a more in-depth idea how properly setup the most power hungry portion of the system.

To wrap it all up, the Big 3 Upgrade is something we at LIS Audio call “setting the foundation” for the audio system. In order to optimize the use of any car audio equipment in a vehicle it is good to upgrade the electrical charging system, add sound deadener to reduce rattles and amplifier bid-bass, upgrading the starting battery to an AGM for better performance, as well ass adding a remote start and alarm to protect and monitor the new investment. These 3 things are how we like to create an ideal foundation for any newly installed system. After all, you wouldn’t want to build a huge house on a weak foundation, would you?

Thank you for reading this LIS Audio Blog! Hopefully you will follow along as we have much more content to release and much more lessons to teach!

More LIS Audio “How-To” Blogs

Speaker Mounting Materials Test

Properly Installing New Speakers

Comparing Enclosure Alignments with Chimpo

Install Overhauls!

Properly Planning Your Sub-stage

Choosing The Proper Wire

Custom Speaker Pods

Remote Start Systems Explained

Benefits of Auto Sounds Deadener

Contact us with any questions you may have…


Call: (913) 912-6990

All images are provided and owned by LIS Audio (Limitless Innovative Solutions, LLC) of Kansas City.

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