Question electrolytic capacitor

[cloudff7]

my search is about the storage time of these devices without compromising the integrity of all the electrolytic capacitors in them due to disuse

[GMB]

The US defence department says that capacitors should be tested and reformed if necessary every 3 years.

[cloudff7]

I don't know about this department but they only test new premium brand electrolytic capacitors and not mounted in electronic circuits and not 31 years old for these electrolytic capacitors?

[GMB]

Their advice was for all grades of capacitors in long term storage (decades). But it was not for in-circuit.

The point is that capacitors need to reform every few years at least. Low voltage ones will often survive rapid reforming but high voltage one may overheat and so need careful treatment.

But a lot depends on luck. Some last 50+ years and some do not.

[Bazz4CQJ]

Why do you think that there should be a simple answer to this?

There are so many variables involved starting with the original quality of the components, and then factors like their usage, on time, off time and the sorts of temperatures they have seen. Generally, higher temperatures leads to faster ageing and so faster failure.

Some defence hardware how has data loggers built in to it which tracks all of the relative parameters from the day of its creation, and which may allow failure prediction. You don't have that, so you cannot do it.

B

[cloudff7]

Is it necessary to turn on the devices monthly to avoid electrolytic capacitor failure?

[Heatercathodeshort]

It depends on the type of electrolytic capacitor.
Modern equipment post 1990's that use the very small aluminium canned types with the black line on the top are a disaster and fail very soon after being put into storage.
There is not a lot you can do about it and unfortunately large numbers are used on modern P/C boards. Mass failure usually writes the equipment off. J.

[cloudff7]

All my equipment was manufactured from 1990 until today but I don't know the brands and types used in the devices.

[duncanlowe]

Can I add that I agree there is NO simple answer to the question. Powering a device to maintain the capacitors is no guarantee. And visual inspection may help but not always. Last week I repaired a clock radio. Not very old because it was DAB, I'd guess 10-15 years. It still worked, but there was terrible mains hum which varied according to whether the radio part was on, the line in was on, or the audio was off. Even with audio off the hum was there which made it no use for use by a bed.

The normal rule to look at bulging capacitors revealed nothing, all looked OK. But I still suspected the electrolytic caps in the power supply. There were two, same value, sae size, and they looked to be power supply. Removing and testing, on read as two back to back diodes, the other a pF capacitor between the wrong terminals of the tester. Replacing them cured the problem.

Why am I saying this on this thread? There is NO guranteed answer to any question about the life of electrolytic capacitors.

It's also worth understanding that there was a massive issue some years ago. Search badcaps.net for a very interesting read.

[cloudff7]

I don't know if I turn on the electronics every day, every month or every year to keep the electrolytic capacitors good they have 31 years of various electrolytic capacitor manufacturers

[Bazz4CQJ]

Originally Posted by cloudff7

I don't know if I turn on the electronics every day, every month or every year to keep the electrolytic capacitors good they have 31 years of various electrolytic capacitor manufacturers

And, as you've repeated been told, neither do we and nor does anyone else.

[Radio Wrangler]

An accurate synopsis, so there's nothing further need be said.

David

[cloudff7]

the pdf of some manufacturers says to reform the electrolytic capacitor every 2 years but my doubt is if this reform is only for new unused electrolytic capacitors on the shelf? does this rule not work on electrolytic caps from 1990 used and soldered on pcb?

[duncanlowe]

Sorry, what is it you are having trouble with understanding about this question on the previous thread? We don't know. No-one knows. Many of us, including myself gave information and examples of why it's impossible to know and give you an answer.

[Cruisin Marine]

Older capacitors on a PCB may be leaky by now and should be changed, especially if they are Tantalum Bead.
On transistor or low voltage equipment, you must power the equipment up and see what happens, normally immediate damage should not be a problem (but not always) except in the case of things like speaker coupling capacitors, be careful of those as they may wipe out and damage the speaker, which may be impossible to replace.

Electrolytic's especially on high voltage valve equipment need to be treated with care by using a variac when you re introduce the equipment to power.

Re forming capacitor's is a subject on its own, I am sure if you search function on this forum you will find plenty of advice.

[Bazz4CQJ]

I find that the eev blog is the best source of information of this subject, see for example https://www.eevblog.com/forum/beginn...32/#msg3330332

A number of threads on the subject can be found using the search function.

B

[HamishBoxer]

That link alone gives details, bottom of there page. Thought we had just had the subject closed ?

[cloudff7]

I read the link but it wasn't sure if this recommendation works for my electronic devices manufactured in the early 90's I don't know if the reform time of the electrolytic capacitor is modified and it is necessary to reduce the interval when the capacitor ages

i not use resistor i use energy my home

[G6Tanuki]

Modern electrolytics don't really need 'reforming' - the bigger issue, particularly with early surface-mount types, is electrolyte-leakage which rots the PCB tracks and component leadouts.

(Sony gear seems rather prone to this - it can render some of their popular portable radios and camcorders suitable only as parts-donors)

[cloudff7]

about electrolytic capacitors in electronic circuits manufactured in the early 90's and early 2000's what is the recommended period of time without use allowed to not cause degradation of electrolytic capacitors due to lack of use and how many minutes to restart it are necessary to completely reform those electrolytic capacitors?