Electrolytic capacitors and reliability

Electrolytic caps are very reliable, if they are rated correctly, and used in an environment where there is little heat.

Most people put their A/V equipment on shelves where there is not enough ventilation, or in places where their equipment runs too warm internally. This leads to a greater frequency of breakdown. I have some equipment that has been running 24/7 for over 15 years, and there were no failures. I installed whisper fans to cool them down.

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Jerry G. ======

I fully realize how small modern products must be and know about switch mode power supplies and do appreciate that electrolytics (including tantalums) are the only game in town.

Just thinking that if someone could solve the reliability problems, they would make quite an impact!

There is an interesting story now circulating about a stolen electrolyte formula (which was missing some crucial additives) and the resultant premature death of many computer motherboards. There seems to be a need for new ideas.

We build avioncs for space applications. There are several manufacturers of military quality electyrolytics. AVX, Kemet, and Vishay are a couple that come to mind right away. You can even order parts with proven established reliabilities rated at 10 failures per billion hours (in the proper application).

AVX even has some commercial components that are in the single-digit per million hours category of reliability.

Some of the GPS satellites have been operating in a very harsh radiation environment 24/7 for 15 years, now, using these types of parts.

Two things you can do to increase the reliability of capacitors; increase the working voltage of the capacitor relative to the operating voltage (less stress on the capacitor), and operate the capacitor at a constant temperature in the middle of its rated range.

There have been new ideas for the last 75 years. Electrolytic capacitors have improved steadily over the years.

However, you get what you pay for. Consumer equipment is notorious for cost-cutting, and components get specified on price rather than longevity. You can buy some electrolytics in ten thousand quantities for a few cents each. They tend to be crap.

High-end electrolytics from well known manufacturers are not cheap, but have lifetimes that could only be dreamed about thirty years ago. However, twenty dollar electrolytics don't get used in consumer products much. They do get used where it matters.