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How To Discharge A Car Audio Capacitor In 4 Different Methods

Don’t know how to discharge a car audio capacitor? Or are you confused about the various methods of doing it? We have got you covered whether you are new or experienced.

There are several ways of discharging a car capacitor. And we have organized the most common and easiest ways for a hassle-free experience. We have divided our guide into two portions. First, we have shown you how to discharge using a resistor and then done the same without a resistor. To ensure your safety, this article starts by discussing the primary safety measures.

Before starting the discharging process of the capacitor, you need to understand the depth of the involved risk. The discharging process is much riskier than the charging process.

The capacitor is designed to discharge high-voltage current rapidly with minimum resistance. Whenever it gets the opportunity to discharge current, it will instantly discharge its current all at once, creating an extreme power surge. Without proper safety measures, it carries the possibility of electrocuting you. So, You should wear

 while discharging it.

Another requirement is using more than the required resistance for bridging the capacitor terminals. Because the rapid transmission of current generates a lot of heat. If the used media for connecting the capacitor’s terminals does not have enough resistance, it will surely burn the used media. Even worse, the capacitor and the resistance media may pop out.

Discharging Car Capacitor with A Resistor

You should know that every process uses the same principle of connecting the capacitor’s terminals to each other. Battery terminals maintain a voltage differential to supply power. When the terminals are connected using a bridge, they exchange voltage, and the net voltage drops to zero.

Now that you have understood the concept of discharging, it will be easier for you to use it in real life.
Although the resistor size varies depending on the capacitor’s size and power, the standard size is 20 ohms, 5-10 watts. And make sure the resistor size is more than enough to handle the capacitor.

Discharging Car Capacitor with A Resistor
Using a resistor, you can discharge in 2 ways. First, wearing an insulated glove, you could simply connect the positive and negative terminals of the capacitor with a resistor. You will see in the capacitor’s display that the voltage is dropping. When the display turns off, you can assume that the capacitor is fully discharged.

Another way is to create a custom discharging tool using a resistor, 12-gauge wires, and alligator clips. Follow these three simple steps for making the custom tool.

  • Make two 15-20 cm long strips of 12-gauge wires.
  • Connect each of the wire strips to each end of the resistor and cover the connection point with tape.
  • In the same way, solder the back side of alligator clips to the other ends of each wire and secure the connection with tape.

Now, you can connect the alligator clips to the terminals of the capacitor. It will create a bridge for voltage transmission. After a few minutes, use a voltmeter to check for net voltage.

3 Other Ways of Discharging Without A Resistor

If you want to discharge your capacitor without using a resistor, there are plenty of ways to do it. You can use a light bulb, screwdriver, or the car itself for the discharging process.

Let us understand them briefly.

Using Light Bulb: The Best Alternative

If you do not have a voltmeter or multimeter to measure the voltage drop, then using a light bulb is the best option for you. Here, you can have a visual indication of discharging.

Make sure to wear insulated gloves before proceeding. You will have to hold both ends of the light bulb against the capacitor terminals. You should see the light illuminating, meaning that the capacitor is discharging. When the capacitor’s net voltage is zero, the light would be completely dimmed off. 

Using a Screwdriver: The Least Safe Option

You can discharge a capacitor with a screwdriver, but it is not advisable by the experts as it can damage the capacitor. But, if you do not have any other way, you may need to stick with this method.

The high conductivity of the screwdrivers supports quick transmission of current. Other ways of discharging occur slowly because of the used materials’ inner resistance. It makes them relatively safer options.

While using a screwdriver, place the metal portion in a way that the screwdriver touches both of the terminals at the same time. You should carefully place your hand on the insulated handle of the screwdriver and ensure you do not touch the metallic portion.

Car System: The Easiest Way

You can use up the power of the capacitor by using your car system, and it will discharge the capacitor.

By simply taking out the car audio fuse, you can prevent the capacitor from charging. After that, you may want to turn on your car audio. Then, you will notice in the capacitor display that the voltage is gradually dropping. It happens because now the capacitor is acting as a battery for your car's audio without charging itself. Make sure to check your capacitor voltage for safety concerns. 

If you do not want to use your car audio, you can go with the traditional approach of using the light bulb. After removing the fuse, connect both ends of the light bulb with the terminals. The light bulb should slowly start dimming. When completely dimmed, the capacitor is fully discharged. 

The Endnote

Discharging a car capacitor is essential before working with it or before relocating it. Otherwise, you may face a severe accident. Discharging requires a delicate process with extreme carefulness to prevent the unwanted quick burst of electricity.

To save you time, we have covered all the essential aspects of the standard approaches. Our guide breaks down each method and serves as an easy manual to follow. 

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