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# Is it possible to salvage "Super/Ultra-Capacitors" from electronic devices? Answered

I was just wondering if someone has ever salvaged a super/ultra-capacitor from some kind of electronic device?
I it possible to even salvage these from something?

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We used to put a large multifarad cap to keep a clock chip for alive for a month.

But the caps regularly failed in use on the pcb. Now, we install a o.47F cap that only keeps the clock alive for two days but instruments are working year after year.

What are you using s-caps for ??

I don't have anything that I can do with the super-capacitors right now, but I did have a couple I ideas about all sorts of gadgets I can make with them, Just wondering if I can salvage them from something because I've heard they are pretty expensive

I bought a set of 5.2v 500F caps to build a never run out flashlight. My first test is if two and later seven can be easily charged in series

( that was one big failure ).

These two units are vastly different ... on 10v limited current supply one is at 5.25v and the other at 3.7v when i had to stop because the first reached its voltage limit. BAH !##%@@!

If you can use these to charge a phone, How much do you think a 5.2V 500F can charge a phone (~2000mah battery on average)?

A phone is charged from a 5 Volt source, so you would need a small step-up switcher http://www.adafruit.com/products/1903 which delivers 500ma at 90% rated efficiency meaning it draws 556ma..

To work out the time we need the start load resistance = 5.2 / .556 = 9.4 ohms.

Using the calculator http://hyperphysics.phy-astr.gsu.edu/hbase/electri...

we find it takes 4900 sec or 81 min or 1.36 hrs for the 500F capacitor voltage to decay down to 1.8 volts.

So you get roughly 1.36hr x 500ma about 680mah charge into the battery.

This is a high estimate because the switcher will either draw more current as the capacitor voltage falls or it will deliver less current to the battery.

3 Months later...

I just a salvaged a 5.5V 1.0F capacitor from a VCR ("Sharp VC-AA50")! It looks basically like a fat 2032 "coin-cell" battery.

I want to build a small flashlight out of it, I know the S-Caps don't hold a charge for long, I'll just make it for fun...

There is no real say if a device has a suitable cap and for what voltage it is rated.
Some small devices use them now as a replacement for a battery to keep settings for a few hours during a power outage.
Usually those are in the 5V region and quite small in size.
Most devices containing serious s-caps are expensive and with a good warranty so finding them on the scrap can be a long process.
Keep in mind that these caps are just recently found widespread uses in consumer electronics.
IMHO the best option these days is to search the net for any good nationally suppliers or otherwise monitor Ebay for a months or so to get a good impression about the available types and prices.

Sure, why not? Un-solder them like any other component.

Yes, Obviously un-solder them like any other component, But is there any specific device where these can be found?

I found one in a telefax machine. Used it to replace a broken one in a hifi radio receiver (it forgot all the saved stations when switched off). Not sure where to reliably find them.

Military surplus electronics is a good source they are also good for precious metals.

When it is no expense limit when new, there are components of pure silver and gold.