I’m sure at one point or another, we’ve all wondered how long do microwave capacitors hold a charge for?. You might be surprised to find out that the answer is not as straightforward as you might think!

In this blog post, we’re going to take a closer look at microwave capacitors and how long they hold a charge. Stay tuned, because, by the end of this post, you’ll know everything you need to know about capacitor-discharge times!

How Long Do Microwave Capacitors Hold Charge

How Long Do Microwave Capacitors Hold Charge?

Every month, capacitors will lose 20% of their charge, and they will lose half of their capacity every year.

Most microwaves include capacitors to adjust the voltage. Microwaves have a lot of inconsistency because of the enormous power they require. The excessive voltage may cause your microwave to malfunction and cease operating.

 With many microwaves on the marketplace currently, it’s difficult to tell which one you have or if you’re getting enough voltage.

While possessing relatively large capacitances of up to 100 milliFarads, some of these circuits could be charged in less than 20 seconds and held the charge for up to 40 minutes. It requires a constant power supply to accomplish this. The capacitor provides this continuous power in combination with the outlet’s power.

A capacitor, especially one used in microwaves, has a life expectancy of 100,000 hours. Depending on how often it is used, this lifespan might range from 5 to 8 years.

After ten years, you’ll need a new capacitor.

The capacitor has a lengthy charge retention period. It may be discharged by attaching it to a low resistance load or by using an external voltage source.

Read More: Can A Microwave Transformer Hold a Charge?

What Are Microwave Capacitors And How Do They Work?

Microwave capacitors are being used in microwaves to adjust the voltage. Microwave ovens heat and cook food using microwaves. 

Microwave ovens employ a high-voltage transformer, which generates inconsistency in power. 

This irregularity may lead the microwave oven to break down, causing it to stop operating. When there is too much power in the system, the capacitor stops any further electricity from entering until it is discharged. 

Microwave capacitors control voltage by allowing a small amount of current to pass through them at a time.

How Long Does It Take For Capacitors To Discharge?

Microwave capacitors control voltage and are usually found in the power supply. They are in charge of regulating the power of microwaves that vary in strength. This is because microwaves can harm your microwave or cause it to cease operating entirely.

A capacitor is an electric device that stores and releases electricity as needed. Its size determines how much time it should take for a capacitor to discharge. 

A microwave capacitor with a diameter of 1-2 inches and a height of 3/4 inch can store roughly 2-3 joules of energy. That means  It can be discharged within around 10 to 20 seconds.

How Do I Know If My Microwave Capacitor Is Discharged?

As you were wondering how long do microwave capacitors hold a charge, you may also wonder how do I know if my microwave is discharged.

Capacitors in microwaves store extra electric energy, which is especially useful when there is a rapid power discharge or surge. It aids in maintaining the microwave’s electric supply’s uniformity. 

Microwaves, like other electrical devices, are susceptible to periodic disruptions. As a result, anytime you attempt to repair the gadget, you should discharge its capacitor to ensure that no one is injured while completing microwave repairs.

There are many ways to make sure that your microwave capacitor is discharged. Such as:

  1. Checking the charge of your capacitor
  2. Using a screwdriver 
  3. By making a capacitor discharge tool.

Checking The Charge Of Your Capacitor

Removing the capacitor from its power supply should be your first step. Remove the microwave’s power cord to ensure that it is completely powerless. Set the maximum DC voltage on your multimeter. This will assist in obtaining the most precise capacitor reading.

 Connect the multimeter probes to the capacitor posts with the multimeter’s probes. Then you can Touch one of the capacitor’s posts with the multimeter’s red lead. After that, connect the black lead to the opposite posts.

 Both leads on the posts can alternatively be held together-the multimeter flashes when the leads meet the posts. The current voltage available in the capacitor will be shown. Continue to contact the capacitor until the voltage drops below 10 volts. Ideally, it should hit zero, indicating that the capacitor has been fully depleted.

Using A Screwdriver 

Don’t you have a multimeter at home? Don’t worry; you can also remove the microwave with a screwdriver. While doing this, try to keep your hands away from the capacitor terminals. 

Take a screwdriver with an insulated handle made of plastic or rubber. Check to see if it has any cracks. Firmly grasp the bottom part of the capacitor. Don’t squeeze it too tightly. With the tip of the screwdriver, contact the capacitor’s posts. 

You’ll hear crackling and see sparks fly from the capacitor terminals. This step will not function unless the screwdriver touches both posts together. Continue to contact the terminals until you don’t see any sparks or hear any crackling noises. This indicates that the capacitor has been entirely discharged. You can confirm by touching the terminals again.

By Making A Capacitor Discharge Tool

Alligator clips, a 20k OHM 5 watt resistor, and 12-gauge wire are used in this time-consuming technique. Cut the 12-gauge wire into two 15-cm-long pieces. Approximately 1.5cm of insulation should be slashed off one end of each wire.

 Wrap the wires with shrink wrap or electrical tape after soldering one end. Connect the alligator clips to the opposite end of the wire using solder. Slowly attach these clips to the microwave’s capacitor’s two terminals. The capacitor will be quickly discharged. 

To continue with the microwave repair, use a multimeter to verify the voltage left in the capacitor. Don’t skip any of the steps listed above now that you know how to discharge a microwave capacitor. These are the simplest and most efficient ways for discharging a capacitor.

 By following any of those steps, you can ensure that your microwave capacitor is discharged.

Signs That It’s Time To Replace Your Capacitor

No matter how long do microwave capacitors hold a charge, these capacitors will ultimately wear out and need to be replaced, just like any other electrical component. There are a few indicators that your capacitor needs to be replaced.

1. Dimming lights: Microwaves used to be able to light up a room with dazzling white light when they were originally introduced. Microwaves can only light up a tiny portion of a kitchen or dining room these days.

 This is the case because the microwave requires greater voltage to operate effectively and give adequate power for bright lighting. If you find your lights dimming as you use your microwave, it’s an indication that your capacitor is going out and will need to be replaced soon.

2. Multiple fuses blowing: Multiple fuses blowing when using your microwave is a frequent symptom that the capacitor needs to be replaced. 

This might be due to today’s high voltage microwaves and higher power demands on microwaves from newer kinds of equipment that rely on magnetic fields to function properly, such as air conditioners and refrigerators.

3. Hissing or popping sounds: If you hear hissing or popping sounds from your microwave when it’s switched on or off, it’s an indication that the capacitor is failing and needs to be replaced quickly!

What Is The Power Capacity Of A Microwave Capacitor?

The capacitor will keep the charge until it is discharged, even if it is disconnected. In most cases, the voltage in your home is 120V. Your microwave’s output voltage is between 2100 and 3000 volts.

Farads are the unit of measurement for capacitors. The capacitor’s capacitance is measured in farads. A higher number indicates a higher rating and hence more power. The capacitance of a microwave capacitor can range from 0.95 to 1.00 microFarad.

A transformer is also contained within the microwave. A transformer is a device that changes the voltage level from one level to another. This converter converts 120 volts from a wall socket to the 2100-3000 volts required to cook your meals.

On the other hand, the magnetron is responsible for converting energy into microwaves. In a circuit, all of these components function together.

Importance Of Discharging A Capacitor

The capacitor will keep the charge until it is discharged, even if it is disconnected. Because your microwave heats food at a very high voltage, the capacitor can accumulate a lot of harmful charges.

You may come into contact with components in the microwave that might complete a circuit while fixing it. You might have a lot of electricity travelling through your body if this happens. It would be best if you discharge the capacitor to prevent this from occurring.

When Changing A Microwave Capacitor, How Long Should You Wait?

This question has no definitive answer. It varies based on the capacitor type, the microwave’s age, and its use.

Microwave capacitors are a crucial part of every microwave oven. The capacitor aids in regulating the flow of energy required to generate the high-frequency waves used in food preparation.

 A capacitor is also employed in these sorts of ovens to help the magnetron’s operation. The capacitor is located within the oven, and it is critical to replace it if it has been damaged or malfunctioning correctly.

Replacing a Microwave Capacitor

If you decide to replace a microwave capacitor that has failed, keep the following in mind:

  1. For instructions on how to install the components, consult your microwave’s handbook.
  1. It’s recommended to get the same component number from the same manufacturer as your microwave.
  1. Ensure the new capacitor you choose is rated for microwave usage and is the same size as the original.
  1. Replace the capacitor in the proper location. Capacitors put incorrectly might explode or cause fires!

Can a Microwave Capacitor Kill You?

You know how long microwave capacitors hold charge but is this charge enough to kill you?

Electricity has the power to kill or seriously hurt humans. While high voltage may appear to be the most threatening, a really high electrical current is the most deadly. A current of 0.01 amps can cause discomfort, while a current of 0.10 amps can be lethal.

Muscle contractions that prevent someone from moving away from a shock, heart attack, or unconsciousness can be caused by 1-10 amps or more currents. Divide the voltage by the resistance to determine the current from the voltage. Ohms are the unit of measurement for resistance. It expresses how simple or difficult it is for current to flow through a certain item.

Hands that are damp or sweaty might enhance the chance of mortality from electric shock. From fingertips to toes, wet hands may have a resistance of only 500 Ohms. You might have a resistance of up to 50,000 ohms with dry hands.

With a high voltage of roughly 2100 V and a lethal current of 10 amps, a resistance of 210 ohms is all that is required to escape the most destructive of shocks. A harmful and occasionally lethal 1-amp current, on the other hand, requires 2100 ohms of resistance. You are at grave risk if you are using your microwave with moist hands.


Now we know how long microwave capacitors hold charge. Microwave capacitors are designed to maintain a charge for a long time; thus, most microwaves won’t need to be replaced. If your microwave no longer heats food, the problem might be that your capacitor has failed and has to be replaced. 

It’s crucial to recognize the indicators of a faulty capacitor before replacing it because the capacitor isn’t the only element of the microwave that has to be replaced if it fails.

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