What’s the Best Car Audio Capacitor?

A car audio capacitor is an electronic component that can store, and discharge electrical energy very quickly. Car audio capacitors are used to filter or buffer any sudden fluctuations in a circuit's voltage, smoothing the ensuing signal. They store a temporary electrical charge that can be released later to feed your hungry amp during peak demands, which prevents your car's lights from dimming when loud bass notes play.

If you've upgraded your car sound system and you noticed that your vehicle has dimming headlights when your audio system is pounding, then that’s a clue that your electrical system isn’t quite up to snuff, and therefore you need to consider buying a car audio capacitor. Flickering headlights are an obvious sign that your amp is struggling with voltage fluctuations.

You might also need a capacitor when the amount of power that you amp(s) requires exceeds the power-generation capabilities of your car’s electrical system, or when your vehicle is equipped with a relatively weak alternator. That said, if your car's charging system is too under-powered, or your amp is insanely powerful, then installing a cap may not be enough, and you should consider upgrading your electrical system - particularly the alternator.

Some people believe that car audio capacitors can also improve car audio system's low end response and overall sound quality. That's not true. The main purpose of using a car audio capacitor is to support the amplifier by feeding it the power it needs for short bursts.

And thereby, prevents the sound from deteriorating due to under-voltage. So, while a capacitor won't improve your sound quality directly, it does make it easier for the amp to perform at its best.

The Top 5 Best Car Audio Capacitors 

BEST CHOICE
Planet Audio PC10F 10 Farad Car Capacitor For Energy Storage To Enhance Bass Demand From Audio System
BOSS Audio Systems CPBK2 - 2 Farad Car Capacitor For Energy Storage To Enhance Bass Demand From Audio System
STARTER
Sound Storm C352 3.5 Farad Car Capacitor for Energy Storage to Enhance Bass Demand from Audio System
Planet Audio PC10F 10 Farad Car Capacitor For Energy Storage To Enhance Bass Demand From Audio System
BOSS Audio Systems CPBK2 - 2 Farad Car Capacitor For Energy Storage To Enhance Bass Demand From Audio System
Sound Storm C352 3.5 Farad Car Capacitor for Energy Storage to Enhance Bass Demand from Audio System
Capacitance: 10,000,000
Capacitance: 2,000,000
Capacitance: N/A
Working Voltage: 16 VDC
Working Voltage: 16 VDC
Working Voltage Range: 16 VDC
Surge Voltage: 24 VDC
Surge: N/A
Surge: 24 V
Dimensions: 9.5 x 6.4 x 2.5
Dimensions: 3 x 3 x 10.3
Dimensions: 11-9 / 16" (H) x 3-15 / 16" (D)
Warranty: 1 year
Warranty: 1 Year
Warranty: 1 Year
-
BEST CHOICE
Planet Audio PC10F 10 Farad Car Capacitor For Energy Storage To Enhance Bass Demand From Audio System
Planet Audio PC10F 10 Farad Car Capacitor For Energy Storage To Enhance Bass Demand From Audio System
Capacitance: 10,000,000
Working Voltage: 16 VDC
Surge Voltage: 24 VDC
Dimensions: 9.5 x 6.4 x 2.5
Warranty: 1 year
BOSS Audio Systems CPBK2 - 2 Farad Car Capacitor For Energy Storage To Enhance Bass Demand From Audio System
BOSS Audio Systems CPBK2 - 2 Farad Car Capacitor For Energy Storage To Enhance Bass Demand From Audio System
Capacitance: 2,000,000
Working Voltage: 16 VDC
Surge: N/A
Dimensions: 3 x 3 x 10.3
Warranty: 1 Year
-
STARTER
Sound Storm C352 3.5 Farad Car Capacitor for Energy Storage to Enhance Bass Demand from Audio System
Sound Storm C352 3.5 Farad Car Capacitor for Energy Storage to Enhance Bass Demand from Audio System
Capacitance: N/A
Working Voltage Range: 16 VDC
Surge: 24 V
Dimensions: 11-9 / 16" (H) x 3-15 / 16" (D)
Warranty: 1 Year

1. Planet Audio 10 Farad Car Capacitor 

Planet Audio 10 Farad

The Planet Audio 10 Farad Car Capacitor comes highly-recommended and many consider it as the best car audio capacitor on the market today. This features a 10,000,000 power capacitance, as well as 16 VDC. It also has a 24 VDC surge voltage. This combination of features make it very durable and capable of withstanding heavy loads.   

Speaking of heavy loads, this car audio capacitor also has a built-in feature that lets you know if you’re overloading your system too much or if your car’s battery is low. The alert tone is very audible. You’ll hear it even if the volume is relatively loud. It also comes with a an easy-to-read LED voltmeter to let you measure the battery levels yourself.  

The only issues we see with this capacitor is that it is not compatible with a 0 gauge wire and that installing it is not very user-friendly.

PROS

  • Audible overload and low-battery warning tone
  • Blue LED voltage meter
  • High power capacitance 

CONS

  • Flimsy surrounding cap material 
  • Hard to install 
Planet Audio PC10F

The Planet Audio PC10F is also an excellent choice if you’re looking for the best car audio capacitor.   

The 16 VDC voltage and surge voltage reading of 24 VDC, the PC10F is very durable. More importantly, it’s capable of measuring voltage accurately. The margin for error is roughly around 0.1 VDC – pretty darn accurate to boot. It comes with a 3-LED digital display with a warning tone that lets you know if you’ve overloaded your car’s audio system or battery or if it’s low battery.   

The best part about the PC10F is that it is lightweight and is easy to install. The manual is pretty straightforward and real easy to follow.   

It also charges fast and powers down automatically when you turn your car off. Just be mindful of the capacitor running hot while charging! 

PROS

  • High-quality remote wire 
  • Excellent full load performance 
  • Added plastic cover protection 
  • Lightweight and Easy to install 

CONS

  • Runs a bit hot while charging
Sale
Planet Audio PC10F 10 Farad Car Capacitor For Energy Storage To Enhance Bass Demand From Audio System
  • 3 Digit Bright Blue Digital LED Voltage Display, Blue Illuminated Window
  • Audible Warning Tone for Reverse Polarity, Voltage Overload and Low Battery Voltage
  • Voltage Measurement Accurate to + / - 0.1 VDC
  • Capacitance: 10,000,000, Working Voltage: 16 VDC, Surge Voltage: 24 VDC
  • Equivalent Series Resistance: 0.015 Ohm @ 100 Hz / 25°C, Capacitance Tolerance: + / - 10%
BOSS Audio Systems CPBK2

When it comes to car audio capacitors, you either have to choose between being lightweight and not carrying high voltage or compact but heavy. However, with the BOSS Audio Systems CPBK2, you can have a car audio capacitor that’s both lightweight and compact without having to give up the ability to keep up with high-powered audio systems.   

Thanks to its 24-volt input voltage and two farads capacitance value, the CPKB2 is a good fit for high-powered systems and will only take a few seconds to charge and power the amplifier.   

As expected, the CPBK2 comes with its own audible alert to prevent overvoltage, reverse voltage, and low voltage. The red digital voltage display also makes reading the voltage of the capacitor easy to read.  

In terms of durability, you don’t need to worry. The CPBK2 is housed inside a corrosion- and weather-resistant material.   

Of course, you do have to give up quite a bit. Because its light and compact, the CPBK2 can’t store as much energy as beefier capacitors. You’ll also have to charge it more often. However, as long as you’re not powering overkill amplifiers, the CPBK2 should do just fine for most enthusiast setups.  

PROS

  • Quick-charging 
  • LED display is easy to read
  • Easy hook-up remote terminal screws 
  • Compact and lightweight 

CONS

  • Lower energy capacity compared to competition 
  • Needs to be charged more often
BOSS Audio Systems CPBK2 - 2 Farad Car Capacitor For Energy Storage To Enhance Bass Demand From Audio System
  • 3 Digit Bright Red Digital LED Voltage Display
  • Audible Warning Tone for Reverse Polarity, Voltage Overload and Low Battery Voltage.2 Farads with digital voltage display
  • Capacitance: 2,000,000, Capacitance Tolerance: + / - 10%, Voltage Measurement Accurate to + / - 0.1 VDC
  • Working Voltage: 16 VDC, Equivalent Series Resistance: <0.00195 mW @ 120 Hz / 25°C
  • Dimensions: 3 x 3 x 10.3, Unit Weight: 3.8 Lbs
Stinger SPC505 Pro

For audio systems that can go up to 5-farads and has a 1,000-watt power capacity, the Stinger SPC505 and its 16- to 18-volt surge range is an excellent choice.   

This car audio capacitor is very capable of stabilizing battery voltage and it has a red LED screen that lets you know vital information. To run, the SPC505 Pro uses 4ga or 1/0ga inputs and it is very good-looking. However, more importantly, it can make your response times and bass clearer while also improving sound quality.   

A capacitor that can be installed like an amplifier, the Stinger SPC505 is an excellent choice for day-to-day use.

PROS

  • Excellent charge-holding capacity 
  • Very small 
  • Good construction quality 
  • Works with 12-volt batteries 

CONS

  • Not a good fit for high-powered systems
Sale
Stinger SPC505 Pro Hybrid 5 Farad Capacitor
  • 16V -18V surge, For systems up to 1000 Watts, 5 Farads, Louder & clearer bass response, Monitor system voltage
  • Stabilizes battery voltage, Minimizes headlight dimming, Similar to a battery/capacitor combo
  • Bright 4 segment red LED display, Accepts (2) 1/0ga or 4ga inputs / outputs or combination of (1) each
  • Unique industrial styling, Louder and cleaner bass response
Sound Storm C352

Do not let the 3.5-farad rating of the capacitor fool you. The Sound Storm C352 is not weak, by any means. In fact, it has a 24-VDC surge voltage with a 16-VDC voltage range. It’s also extremely flexible – it’s got roughly a +/- 10 percent tolerance percentage.   

The display screen might be small, but it is visible enough with its small red text display. More importantly, it’s also very durable. This is because of its chrome-plated posts. It also comes with mounting brackets and other additional hardware for easier installation. Plus, because it is lightweight at just below 4 pounds, you can probably install it yourself.   

Just keep in mind that it’s not as small as it looks, and as such, you need to be careful with the installation. Also, charging the capacitor takes a bit longer compared to others.  

While it may look small, it is actually a bit larger than expected. This may make things more difficult during installation, but it shouldn’t impact the process too much. It also may take up to a minute to charge the capacitor. You should only worry if it takes longer than that. Another drawback is you need to purchase wires to properly hook it up. 

PROS

  • Lightweight 
  • Easy installation 
  • Hardware and mounting brackets included 

CONS

  • Takes a while to charge 
  • Larger than it looks
Sound Storm C352 3.5 Farad Car Capacitor for Energy Storage to Enhance Bass Demand from Audio System
  • Capacitance Tolerance: + / - 10%
  • Working Voltage Range: 16 VDC
  • Surge: 24 V
  • Chrome Plated Posts
  • Mounting Brackets and Hardware Included

How do I hook up a car audio capacitor?

Whether you've purchased a cap to prevent your headlights from dimming, or just for precautionary measures, you need to install it. You don't need to spend hundreds of dollars for an easy installation that you can do yourself. One should always take caution when handling wires and electrical systems.

Before installing a capacitor, you must charge it (more on that down below). Use a voltmeter along with a resistor to charge your car audio capacitor. Once the voltmeter shows 12 volts, the power capacitor is fully charged. Now you can proceed to wire the capacitor in parallel with your amp.

Installing a car audio capacitor isn't rocket science, although it can be dangerous. Since large capacitors are capable of storing a great deal of wattage, you should be careful when installing yours. For safety purposes, new car audio capacitors are sold completely discharged.

So, before attempting installing your new capacitors, please read the safety and installation instructions before you get started.

New car audio caps usually come with a resistor or a wired light bulb that can be used to discharge the capacitor slowly and safely.

As in all car electronic installations, the very first thing that you should do is to disconnect the ground cable from the car battery. In this installation, also take out the in-line fuse on the amp's power wire next to the battery.

Bear in mind that your capacitor should be mounted close to your amp using the shortest wires possible. Also make sure the cap gets mounted securely.

Car audio capacitors have two terminals : a positive and a negative which should be clearly marked on the capacitor. The positive pole should be hooked directly to the positive amp connection, and the negative pole should be attached to your chassis ground — preferably in the same place as your amp.

How to charge a car audio capacitor?

To charge your capacitor, simply follow the steps listed below:

  1. Remove the fuse that connects your car audio system to the battery. It's usually in-line with the power wire of the amplifier that your capacitor is going to be connected to too.
  2. Now wire up your capacitor following the instructions detailed above.
  3. To begin charging your capacitor you'll need either a resistor or a test light. These are often included with the purchase of a capacitor but can be purchased separately if necessary. Charging a capacitor using a resistor is quite different from charging it using a resistor. We'll detail both methods.
    1. Using a Resistor : You will need a 1 watt, 30 – 1,000 Ohm (1kohm) resistor for charging your capacitor unless otherwise specified. It's highly recommended that you use a higher impedance resistor so that your capacitor is charged slowly. Put the resistor in line with your fuse holder, as though it were the fuse. Place the voltmeter positive(+) lead on the positive terminals of the capacitor and the negative(-) lead on the ground terminal of the capacitor and set the meter to Volts DC. Once the volt meter reads 11 or 12 volts you can remove the voltmeter and replace the resistor with the power fuse.
    2. Using a Test Light : A test light is the simplest and easiest way to charge a car audio capacitor. All you need to do is take the power and ground of the test light and place them in-line where the fuse used to be. To make it easier, use use alligator clips. Hold the test light in place of the fuse until the light bulb turns off which indicates that the voltage went from 12V to 0V and the capacitor is charged.

How to discharge a car audio capacitor?

There are various ways to discharge a car audio capacitor. The most important thing is to discharge it slowly. Here are a few methods you can use to discharge your capacitor :

  • Method 1 : Disconnect and remove the capacitor from your vehicle.  Use a 12V test light or resistor to bridge the positive and negative terminals on the cap together. For safety purposes, wear safety goggles and heavy duty gloves or hold the test light or the resistor with insulated pliers. If you've used the resistor to bridge the terminals of the cap, you'd know that your cap is fully discharged when the resistor becomes cool. If you've used the test light however, you'd know that the cap is discharged when the light goes out.
  • Method 2 : Another easy way to discharge the capacitor is to simply remove the main fuse that's located between the battery of the car, the capacitor, and the amp. This will make your capacitor the main source of power and act as the battery for your entire audio system. Then, turn on your audio system and wait for a few seconds till the amp turns off completely signaling that the cap is fully discharged.
  • Method 3 : Simply remove the capacitor from your car and connect it to any device that uses 12V DC for power. Keep the device running until all the energy stored in the capacitor is consumed. The device will then shut off indicating that your capacitor is discharged.

To make sure your capacitor is fully discharged, use a multi-meter or voltmeter and check the voltage across the terminals of the capacitor. If the meter reads zero volts or very close to it, your car audio capacitor has been successfully discharged. If you want to connect it again, don't forget to recharge it. 

Conclusion 

The most important thing when looking for the best car audio capacitor is to make sure that it is suited for your system.  

 
Farads, in particular, is a major factor. You’ll need to have enough farads to have enough power for your system. Otherwise, you’ll end up putting your system or even your car or yourself at risk. At best, you’ll need two farads for a 2,000-watt system, although having more never really hurt. 
 

In general, the more powerful your system is, the more farads you’ll need.   

Ultimately, you should now be able to choose a proper car audio capacitor. This is especially true with added research.

Last update on 2021-01-21 / Affiliate links / Images from Amazon Product Advertising API