Posted on

What are high output alternators?

2JZ High Output Alternator

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. 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 high output unit that provides 100A at idle speeds and a water-cooled unit that provides upwards of 350A. There’s also a difference between simple re-winds and units that are remanufactured from the ground-up.

Why Factory Alternator Amperage Output Isn’t so Hot

The first alternators blew older dynamo generators out of the water in terms of raw amperage output. However, the electrical systems that they had to supply in the 1960s were nothing compared to the electrical systems today. Many early factory alternators were only capable of putting out a maximum of 30A, which is a number that many modern stock units beat at idle speeds.

Today, a typical OEM alternator in an average passenger car or light truck can put out somewhere in the neighborhood of 50-80A. However, there’s a variation from one application to another.

The rated amperage refers only to its output at 6,000 RPM, which is why a 108A alternator may only put out 40 or 50A at idle speeds.

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.

When Enough Isn’t Enough

Although a vehicle’s electrical system is fairly complicated, you can get a good idea of whether you need a high output alternator by performing a few calculations. For example, wattage is determined by multiplying amperage by voltage, so an 80A alternator is capable of putting out:

80A x 13.5V = 1,080W

That’s plenty of power for any factory sound system. However, if you add amplifierssubwooferssubwoofer amplifiers, and other power-hungry components (on top of everything from headlights to a cooling fan), it’s easy to see how you might need a high output alternator.

It’s also important to remember the difference between idle output and rated output. If the rated output of an alternator is 80A, it is only capable of delivering that much amperage when the engine is revved up. Both ISO and SAE standards use 6,000 RPMs to determine the rated amperage of an alternator, which roughly corresponds to 2,000 to 3,000 engine RPMs.

Posted on

XS Power Wattage Chart


Choosing which battery to use to power your audio system can be daunting when faced with all sorts of numbers and specifications that don’t seem to have anything to do with car audio at all. With our wattage chart below, the choice has never been easier! When using only one battery, refer to the “Primary” column; when using a second battery as a supplemental battery, refer to the “Secondary” column. When replacing the original battery and adding supplemental power, use a combination of the two columns to arrive at the desired level of power needed to satisfy any stereo system!

Posted on

XS Power Frequently Asked Questions


What is an AGM battery?
Absorbed Glass Mat (AGM) Batteries completely eliminate the hassles of conventional battery maintenance. There is no liquid acid in AGM batteries. All of the acid is absorbed into the compressed glass matting in the cells. They are completely Non-Spillable, so they can be shipped by mail or courier service with no hazardous warnings or extract fees. Likewise, they can be mounted in any position for special application.

How do I charge an AGM Battery?
AGM batteries should only be charged with AGM compatible chargers. Please view our full XS Power 1004 16V and 1005 12V/14V/16V charger manuals for complete instructions.

Could you explain “MAX amps”?
CA and CCA have been used since 1914 as a definition for battery performance. CA is defined as a measurement of the number of amps a 12 Volt battery can deliver for 30 seconds at 32°F and not drop below 7.2 volts. CCA is the same test at 0°F. These tests were meaningful for the cars of yesteryear that had to be cranked for a long time to get started. Back then CA and CCA numbers were very meaningful; however, for mobile audio use, immediate burst output is more important. XS Power batteries, when compared to the batteries of yesteryear, deliver much more power more quickly. This instant burst energy is what we call “MAX amps”.

Could you explain “amp hours”?
People often wonder what the term “amp hours” means when referring to batteries. Many people assume that “AH” (amp hours abbreviated) is a standardized rating for a battery’s ability to discharge current; a true statement. The actual method for de terming the AH rating is more often times not fully understood by the automotive enthusiast.
AH capacity is measured in hours. AH is most commonly used to rate deep-cycle type batteries, or any type of battery used for relatively low discharge rates across an extended period of time. Most batteries, including XS Power batteries, are tested in a 20 hour cycle. AH tests can be performed for 10 hour cycles at a higher amp load, but results are not as useful for determining long term capacity.
An AH test can easily be conducted by the end user, which is why we at XS Power are so adamant about strict honesty regarding all of our battery ratings. To conduct your own AH test, simply calculate 5% of the AH capacity, and use that number as the amp load. Make sure the battery maintains the standardized 25°C temperature for the duration of the test. The idea is that the battery needs to maintain that load for 20 hours without falling below 10.5 volts. Please note that 16 Volt batteries would be tested to 14 Volts.

Here is an example for a 30 AH 12 Volt battery:
5% of 30 (amp hours) = 1.5 amps.

A 30 amp hour battery should be able to maintain a 1.5 amp draw for 20 hours at 25°C without falling below 10.5 volts.
When a manufacturer is initially determining AH, the calculation is done in reverse. The amp draw is multiplied by the test cycle length in hours as evidenced by the example below.
1.5 amps x 20 hours test = 30 AH

The AH rating is most useful for determining how well a deep cycle battery can maintain a relatively low amp load across an extended period of several hours, as the example above illustrates. This information is especially important to customers who plan to use XS Power batteries in Recreational Vehicles (RVs), boats, show vehicles, or any other application vehicle that will need to sustain a low draw for extended periods without being charged.

What does BCI Group Number mean?
The BCI Group Number defines a battery by describing the following characteristics:

A.) Its maximum dimensions (L x W x H)
B.) Voltage (6 volt or 12 volt)
C.) Post configuration
D.) The type of terminal used (top, side, flag, etc.)

It should be noted that the BCI (Battery Council International) Group Number does not designate a battery’s capacity, it merely defines the above listed physical characteristics.

Could you explain reserve capacity minutes?
Reserve Capacity is yet another standardized battery rating useful in selecting the proper battery. Usually abbreviated “RC,” reserve capacity is measured in minutes. Battery Council International defines RC as: “the number of minutes a new, fully-charged battery at 80°F (27°C) can be discharged at 25 amps and maintain a voltage equal to or higher than 1.75 volts per cell.” This works out to 10.5 volts for a 12 Volt battery.

For example, the XS Power S925 battery has a rated RC of 55 minutes. This means that with the S925 starting at a full charge at 27°C, it can maintain a 25 amp load (similar to a large cooling fan) for 55 minutes before battery voltage drops to 10.5 volts.
It is easy to see how this rating is very important in determining how well a battery will operate accessories in the event of a charging system failure, if the vehicle is not properly equipped with an alternator or if the vehicle’s engine is not running.

How do I determine the state of charge of my battery?
By measuring the open circuit voltage (OCV) of a battery that is not connected to any loads, it is possible to determine what percentage of capacity is remaining by referencing the chart below.


Are all 16 Volt batteries tested alike?
Unfortunately, no. XS Power is a member of BCI (Battery Council International) and tests all our batteries to BCI specifications. We test our 16 Volt battery to 16 Volt specifications. Other suppliers of 16 Volt batteries test to 12 Volt specifications. If XS Power batteries were tested the same as our competitors, our CA numbers would be considerably higher.

Why do XS Power batteries cost more than flooded batteries?
XS Power batteries are manufactured using only virgin lead, 99.99% pure compared to most batteries that use recycled lead. The pure-lead design means better performance. In other words, MORE POWER!

Grids are thinner. This allows for more grids which means more surface area in a smaller package. More surface area means MORE POWER!
AGM (Absorbed Glass Mat) design means longer life, vibration resistant, deep cycle and can be mounted in any position (except upside down).

Why XS Power Batteries?
We believe that to create a superior product you must have a vast knowledge of your product offering. For this reason we have invested a great deal of time and money into the development and understanding of our batteries and the markets we supply. This task could not be completed with run-of-the-mill test equipment. We worked in cooperation with one of the worlds largest and prominent battery testing equipment manufacturers to develop a one of a kind test lab that would enable us to duplicate circumstances realized in real world battery applications. Our battery tester is capable of being programmed to simulate a wide range of scenarios like the dynamic current loads from an amplifier for daily driving, or the insane power demands from top sound pressure competition vehicles. We are convinced that in-depth testing and quality control is a must for any manufacturer that is serious about delivering quality batteries to the mobile audio market. Buy from the people who understand both the market and the product – XS Power!

Battery Comparison: 
Get more continuous amps for less weight! Why drag around extra weight for less power?

Ultra Low Internal Resistance:
XS Power batteries design allows for extreme amounts of discharge current, as well as super fast recovery and recharge rates. XS Power batteries are ideal when you want to add that extra boost for your stereo without having to upgrade the entire electrical system.

Greater Performance:
Don’t let the small size and weight of XS Power batteries fool you. The cranking power of XS Power Batteries can be two to three times the power of a flooded battery of equal size. Take for example the XS Power Battery Part Number S925. It will often out perform and last longer than the bigger battery that comes original equipment on a new car. This makes XS Power the ideal battery for race cars, street rods, and daily drivers.

Since there are no external vents on an XS Power battery, there is no fear of mounting it in a passenger compartment, below a seat, or inside a glove box. No leaks mean no corrosion or damage to chrome or paint. We are so confident in the safety of XS Power batteries that we guarantee no acid leak even if damaged.

Extreme Vibration Resistance:
Rigorously tested to withstand insane amounts of vibration allows XS Power batteries to be installed inside the harsh environments of the trunk or hatch areas where sound vibrations can ruin the average battery.

Sealed Design:
The perfectly sealed design of the XS Power AGM Batteries allows safe, maintenance free operation, allowing them to be used in nearly any position without sacrificing life expectancy or performance. This means there is no need to constantly check and refill the electrolyte and no more corroded terminals to clean!

Excellent Storage Life:
XS Power Batteries are perfect for show cars or situations where the batteries are left unused over a long period of time. A fully charged XS Power battery can sit for up to a year at room temperature and still have the power to produce when you’re ready.

Still Have Questions:
 If you would like to speak to an XS Power professional immediately, please call 888.4XS.POWER.

Posted on

Big 3 Wiring Upgrade Kits

Big3 Upgrade

Our Big3 Wiring kits have more Copper than any other manufacturer. Period.

True 1/0 Pure Copper Big 3 Wiring Upgrade kit
1/0 Pure Copper cable.
46″ Positive, 34″ Ground, 32″ Ground
All cables include copper lugs crimped & heat shrink.

Big3 is required for all high amp and high output alternators.
+$89.00 Your #1 Source for High Output Alternators??.

Receive a Quote






Contact Us


Posted on

The Big Three Wiring Upgrade

Big3 Upgrade

Do I need the Big Three Wiring Upgrade?
Wondering what the Big Three Wiring Upgrade is and why you’d need it?

In a previous article, we discussed some of the undesirable effects low voltage can cause, like headlight dimming and how to determine that voltage is the culprit.

Your car is made to efficiently utilize its stock electrical charging system. The factory wiring in your car is no different. It will provide sufficient current for the electrical components in the car.

Adding a high-powered amplifier to that electrical load can put a strain on your charging system. Your stock system may not be able to keep up with the amplifier’s power demands.

Continue reading The Big Three Wiring Upgrade