[Explained 4 Facts] Do Capacitors Expire?

Yes, capacitors can become obsolete. The type of capacitor, the environment it is stored in, and the way it is utilized are some of the variables that affect a capacitor’s shelf life.

The most popular type of capacitor, electrolytic capacitors, has a short shelf life. Depending on the component’s quality, an electrolytic capacitor’s shelf life can be anywhere between two and ten years. The shelf life of other capacitor types, like ceramic and film capacitors, is greater.

Why Do Capacitors Expire?

In this section, we’ll explore the reasons behind capacitor expiration and understand the factors that contribute to their limited lifespan.

1. Temperature and Thermal Stress

Capacitors’ aging process can be accelerated by high temperatures. Long-term exposure to high temperatures can cause a decrease in capacitance and an increase in internal resistance. The expansion and contraction of capacitor components under thermal stress from temperature changes can result in mechanical stress and probable failures.

2. Voltage Stress 

Voltages greater than a capacitor’s rated voltage might stress the dielectric material, hastening the degradation process. Also, voltage surges or spikes can also result in dielectric material breakdowns, which lower capacitor performance and life.

3. Quality of Manufacturing

The materials used and the quality of the manufacturing process can both affect the lifespan of a capacitor. Low-quality or improperly made capacitors could operate for a shorter period of time.

4. Environmental Aspects

Capacitor degeneration can be caused by harsh environmental factors such as excessive humidity, dampness, and exposure to chemical pollutants. Capacitors used in outdoor or commercial environments may degrade more quickly.

How Long Does They Last?

Unlike perishable commodities, capacitors do not have a set shelf life, although they are susceptible to deterioration over time for a variety of reasons. Electronic components called capacitors are used to store and discharge electrical energy.

Due to variations in design and construction, many capacitor types, including electrolytic, ceramic, and tantalum capacitors, have varied lifespans. The list of factors that affect the lifespan of capacitors is given below.

Electrolytic Capacitors

The most popular kind of capacitors are electrolytic ones. A metal plate, an electrolyte, and yet another metal plate are used to create them. A liquid that conducts electricity is called an electrolyte. The electrolyte allows electrons to go from one plate to the next when a voltage is applied to the capacitor. 

Fig. 1: The lifespan graph assuming full ripple current operation

As a result, the plates acquire a charge that can be saved for later use. Since the electrolyte can dry up or evaporate over time, electrolytic capacitors have a short shelf life. As a result, the capacitance may drop and the leakage current may rise. Depending on the component’s quality, an electrolytic capacitor’s shelf life can be anywhere between two and ten years.

Ceramic and Film Capacitors

Other types of capacitors include ceramic and film ones. They don’t need an electrolyte, hence their shelf life is unrestricted. Film capacitors have a 30-year lifespan while ceramic capacitors have a 20-year lifespan.

Frequently Asked Questions and Answers – FAQs

Do Capacitors Go Bad if Not Used?

Yes, capacitors can degrade if they go unused for a long time. It’s common to hear people refer to this condition as “capacitor aging” or “capacitor drying out.” It mostly affects electrolytic capacitors, particularly aluminum electrolytic capacitors, whose correct operation depends on an electrolyte.

Do Usage Patterns and Operational Circumstances Matter Capacitor Health?

Capacitors may deteriorate more quickly in circuits with frequent power cycling, voltage swings, or high-frequency operation. Premature failure can result from continuous operation close to the capacitor’s maximum rated conditions.

Conclusion

They don’t have a set lifespan; instead, several variables, including the type of capacitor, ambient conditions, usage habits, and manufacturing quality, can affect how long they last. To guarantee the dependability and lifespan of electrical devices and systems, capacitors must be regularly inspected, tested, and, if necessary, replaced.