Electrolytic caps

[krellmk]

Do unused electrolytic capacitors degrade over time?

 

[WOPL Sniffer]

Do unused electrolytic capacitors degrade over time?

We had a post quite some time back but if you believe the military, yes. There IS a shelf life.

 

[WOPL Sniffer]

Here is a couple blurbs from around the horn

SHELF LIFE AC capacitors are expected to perform for their full service life objective after being exposed to a maximum shelf life of 10+ years when stored in a controlled environment.

Many manufacturers specify a typical shelf life for a capacitor or an assembly containing capacitors. The manufacture's stated shelf life for an aluminum electrolytic capacitor can range from 2 to 10 years, depending on the quality of the component (Kogler, 1999).

 

[Gepetto]

Form them again if they have been sitting for a long time...

 

[NeverSatisfied]

Form them again if they have been sitting for a long time...

How is that done ?

 

[NeverSatisfied]

This might not be the correct place to ask this question but the original Capacitor question got me wondering.
I have many vintage systems and I have a routine of making sure that I fire up each system at least once a month and run each for at least 30 minutes to an hour.
I know it's good for mechanical systems like turntables and to a lesser degree speaker drivers but does it do anything positive for the electronics ? Or am I just using up one more of the finite heat cycles that most electronics seem to have before something fails ?
Your opinions are appreciated.

 

[WOPL Sniffer]

great for a vintage car, won't help a stereo

 

[Gepetto]

How is that done ?

This works with loose, uninstalled caps. Put 1k in series with the cap and apply a DC voltage to it, observing correct polarity. The DC voltage should be close to the rated cap voltage. Leave for 24 hours. Monitor the voltage across the 1K resistor. Over that 24 hours it should diminish to almost zero.

 

[8991XJ]

Reforming called Voltage Treatment by Nichicon is on page 18, Storage Performance section of this pdf
https://www.nichicon.co.jp/english/products/pdf/aluminum.pdf
Tells you what you need to know and that it is beneficial to power up your gear every month.

Some companies reformed the large caps as a step in production back in the day.

 

[WOPL Sniffer]

Reforming called Voltage Treatment by Nichicon is on page 18, Storage Performance section of this pdf
chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/viewer.html?pdfurl=https%3A%2F%2Fwww.nichicon.co.jp%2Fenglish%2Fproducts%2Fpdf%2Faluminum.pdf&clen=1243339&chunk=true

Tells you what you need to know and that it is beneficial to power up your gear every month.

Some companies reformed the large caps as a step in production back in the day.

For 40 year old caps?

 

[WOPL Sniffer]

Reforming called Voltage Treatment by Nichicon is on page 18, Storage Performance section of this pdf
chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/viewer.html?pdfurl=https%3A%2F%2Fwww.nichicon.co.jp%2Fenglish%2Fproducts%2Fpdf%2Faluminum.pdf&clen=1243339&chunk=true

Tells you what you need to know and that it is beneficial to power up your gear every month.

Some companies reformed the large caps as a step in production back in the day.

Can you paste that link again? It don't work

 

[8991XJ]

https://www.nichicon.co.jp/english/products/pdf/aluminum.pdf

 

[8991XJ]

For 40 year old caps?

If they are not totally dried out and dead, keeping them properly formed is better than not. Replacing is always an option.

I was more just supplying info requested not worrying with saving out of date caps and such.

 

[WOPL Sniffer]

Since there IS a Life Estimation Table, it is only reasonable that they will be affected by storage.

 

[WOPL Sniffer]

Since the question was "Do unused electrolytic capacitors degrade over time?" I say yes and would not use a stash of NOS caps that are umpteen years old when fresh ones can be had for pennies.

 

[laatsch55]

 

[WOPL Sniffer]

That's a "Vent" for sure. They should have Formed the banana peels better

 

[laatsch55]

Amen...