To be clear, he's talking about degradation of 20 or 30 years.
A year? Two? Five? I'd say you can pretty much not worry about this advice.
If you live in the desert and keep things stored in a relatively cool and stable environment, then I'd bet on 20 years before any measurable degradation takes place.
I'm just a hack though, I'll hope Kirbic weighs in and corrects my assumptions above.
20 or 30 years??? Maybe if you're talking about the normal time for the electrolytic material to break down assuming normal usage. For storage, the time is less.
The Panasonic guide for capacitors says the recommended storage time for Al electrolytic caps is one year. Any longer and they need reconditioning... Keep in mind that there's a fair amount of CYA in this document, but the breakdown time for capacitors in storage isn't decades.
There's also Capacitor Plague associated with low-cost Taiwanese caps.
There are lots of failure modes for capacitors, most likely they'll just gradually degrade over time. Other times they'll go POP and blow open the vent or start to leak and cause a short...the list goes on.
20 or 30 years??? Maybe if you're talking about the normal time for the electrolytic material to break down assuming normal usage. For storage, the time is less.
The Panasonic guide for capacitors says the recommended storage time for Al electrolytic caps is one year. Any longer and they need reconditioning... Keep in mind that there's a fair amount of CYA in this document, but the breakdown time for capacitors in storage isn't decades.
There's also Capacitor Plague associated with low-cost Taiwanese caps.
There are lots of failure modes for capacitors, most likely they'll just gradually degrade over time. Other times they'll go POP and blow open the vent or start to leak and cause a short...the list goes on.
I'd agree, but with the caveat that environment matters a great deal.
Cool, dry storage without temperature swings? A couple of decades really isn't improbable.
"Appropriately, this little insight into capacitors came as a "by the way" moment during a recent conversation with Paul Buff. Paul designed and built these Ultras nearly 30 years ago in the mid-1980's, which is exactly when I was first getting serious about my lighting. (Suffice to say I used the living crap out of these lights.)"
Now granted, he didn't say 'stored' for 30 years, but clearly these are old lights he's talking about - not a speedlight that was bought two years ago and stored for a year.
I've personally fired up 3 flashes that I KNOW were completely unused for at least 3 or so years, and probably more like 5 years. Nary a problem among them - although I may have unintentionally done something rather similar to what he suggests for conditioning (full power, flash the snot out of it - with a few rests in between)
*shrug* I'm a risk taker, and I just try not to get too worried about stuff like this. I'll absolutely agree that anything around 5 years is suspect and this is a fine idea. Anything that's been stored for a year or two? Sorry, just can't see this being needed (and I store, refurbish, and use plenty of old junk electronics. This week has been a week of enjoyment with the Canon D60)
One application in which 'lytics are used where storage can become a real issue is variable speed motor drives. These drives work by convertin an AC input to DC and use a capacitor array to store energy and create a stable high-voltage DC bus that can be converted back to AC as output using PWM (pulse-width modulation).
One manufacturer of these drive (Eaton) recommends specific re-forming procedures for drives that have been stored un-powered for more than one year.
Motor drives are a severe case; because of the size and power of the caps, the risk of explosive failure is higher. Where risk is lower, a more laissez-faire approach may be fine, as long as an occasional loss of the equipment involved is not to much risk to bear.
As I said, the engineers who wrote that guide would put a lot of CYA in that document and err on the side of great caution. That way when an 18 month old cap blows up, the company can point to that document and say, "See, we warned you."
All capacitors are not equal either...see the aforementioned Capacitor Plague article. The same kind of quality issues can certainly affect the breakdown of capacitors in storage.
