Capacitor durability

How reliable is a capacitor?

For example, the failure rate of a capacitor is in actuality related strongly to its energy storage, which is proportional to the square of the rated voltage, and yet in the MIL Handbook there is no reliability factor for the rated voltage, only for the capacitance.

How long does a capacitor last?

In general capacitor lifetime (including supercapacitors) is dependent on three things: If you want the capacitor to last a long time, limit the applied voltage, keep it cool, and limit the output current. All this should be in the datasheet of your capacitor.

Do ceramic capacitors have a longer life than film capacitors?

Ceramic capacitors normally have a longer lifetime than either of the two technologies above. The effects of voltage and temperature are given by: L = LR x (ER/EO)3 x (8 x TR/TO) In film capacitors, the effect of reducing temperature is like the aluminum electrolytic, but the effect of voltage derating is much greater.

Are smaller capacitors more reliable than larger capacitors?

It is the case, therefore, that the failure rate of the bank is approximately equal to the number of capaci-tors in the bank multiplied by the failure rate of each capacitor. It is generally true that smaller capacitors (CV rating) are more reliable than larger capacitors.

What is the failure rate of a capacitor?

This basically means that for a given capacitor family (type, such as CDE 550C), temperature, and voltage derating, the failure rate is proportional to the product of the rated voltage and the square root of the capacitance.

Why do aluminum electrolytic capacitors have a limited life span?

The aluminum electrolytic capacitor has a limited life span. This occurs because the electrolyte in the element eventually dissipates. Eventually, the capacitance begins to drop off. The tangent of the loss angle begins to increase. Generally, when voltages are applied, the leakage current begins to drop.