Testing a supercapacitor 

Awesome calculator, love that the site is nice and clean and simple so I don't need a supercomputer to run it. And the cat is a good bonus.

Where are such big capacitors used??

What is name of the cat .🙂

"CatCoolEther" 😹

Haha, a CatCuteLator 😻 Good that your supercapacitor turned out legit.

I've had this EXACT same super cap for a few years. I've abused it heavily (i.e. charging at 15A and then dumping it through thin wires to watch them explode, etc.). The leads have even half melted away

I just got this EXACT capacitor and was dreading trying to determine its true capacitance! Well timed video 🥰

Ohm's Law page is a genius tool to make calculations easy. I like this.

I’m looking forward to some rapid discharge experiments with that supercapacitor. 😈

Your site is very handy but very hard to read. Went nuts with colours and background did you?

Would love to see a conversion chart for awg/wire thickness to ohms at a certain distance... that way I could very easily calculate the expected voltage drop or vice versa the resistance of a wire when I know the voltage on both sides

Thanks for the catculator. Very helpful tool. I need that regularly.

a tip for yout site. you used an image for background. this way dark themes dont work , put just a color.

Awesome vid man along with your catculator. Bookmarked for future use.

I hope you are going to finish your work on that bench power supply. I was enjoying that.

I though there were only 10 F maximun capacity super caps a 500 F blew my mind

A suggestion for your website is to add a calculator for the internal resistance of batteries. It can be done with ohms law and measuring the voltage drop on a set resistance

I have 3000f 2.7v super capacitor I convert it to Ah =1.2 2.7v to 100mV

Nice video! the resistor at 7:08 is made in soviet union? I also have a few of them at home...

SUPERB! I used 4 such as driver to my UPS. But after few months I realised it takes too much Power on self discharge so I redesigned the UPS to use 18650 - much less $ wasted ;)

You speak like singing with some pattern at end of sentence. Nice. Felt like Sanskrit slokas initially.

catkoolator 🍭

everytime i see an cap this big (from its physical size) "the forbidden lollipop" pops up in my mind

Great information ever 👍❤️

What a disepoint movie. Realy waiting on kaboom lol.

Sovietski resistor nice :D

I hope Electroboom will like your videos

I love your Web site it has your lovely cat picture on it :0

Kámo 🤣 trochu zapracuj na výslovnosti plís. Ic lajk jů spík lajk dys fór eprůvl

I love your calculator so much

Nice website

Years ago i looked into capacitor charging times, the number of time constants was rather crude. I ended up with a exponential calculation. But my memory has faded a lot :-( Very nice calculator on your site, it will help many people :-D

Very interesting! Easiest way for these calculations is to measure/calculate the rate of which the voltage is rising or falling during charge/discharge (in volts per second). Rase/fall rate (volts per second) times the capacitance is the current (A). Current (A) divided by rise/fall rate (volts per second) is the capacitance. Current (A) divided by capacitance is the rise/fall rate (volts per second). For example the 500 F getting charged to 2.4 V in 1 hr is 2.4 / 3600 = 0.0006666... V/s - so 0.00066666... * 500 = 0.333333... A - or charge it by 300 mA is 0.3 / 500 = 0.0006 V/s, 0.0006 * 3600 = 2.16 V. The inaccuracies was probably because electrolytic capacitors (even good ones) have a tendency to have some residual charge that can mess with measurements like this. It behaves like there is another, small capacitor with extremely high ESR in parallell with the main one. You can see that if you charge an electrolytic capacitor, hold it at a constant voltage for a while, then discharge it thru a low value resistor (with a voltmeter in parallell) and disconnect the resistor once the voltage is down to 0 V, with the high impedance volt meter still connected - the voltage slowly rise again (even if nothing is charging it), up to a few tenths of a volt or sometimes (if it's high voltage capacitors) up to one or several volts before it stabilizes. If the leads are shorted, then disconnected again, it will do the same (but the voltage rise be less for each time). The load (or terminals shorted) has to be left on for some time, to make the voltage stay at zero when the load is disconnected. Same thing happens if charged up and held at a constant voltage while leakage current is measured - it will be quite high initially, then go down and settle at a very low current after 10-30 seconds or so. As I understand, this is a natural behaviour of electrolytic capacitors and nothing really wrong. Capacitance measurements of a capacitor like this will probably be more accurate, if the rase/fall rise rate is measured while it already have been charging for a minute or so at a constant current. Also 2 measurements during both charge and discharge could be taken (in case that residual charge effect will be different during rise and fall).

Wow; we are somehow connected or something - because for the past few weeks I've been playing with EDLCs of many types; including these exact 500F units - brand and all! Of the 10 I got, 2 were DOA; and another two were lost during storage - It seems these may be rejects, as some even 'rattle' somewhat... My biggest "IF" here is the self-discharge, it could be lower on these... Some EDLCs are really good though, so parts selection via individual measurement is the way to go; measure the capacity and then how long it takes to "bleed" down. Those small button-style Ni-MH cells are good to mess around with in calculators and such; as you can 'buff' them with sealant over the gasket - which helps stop leakage. They are also $1 for a replacement* - supercaps are a bit of a gamble on ebay; and expensive as hell in-store! Though the investment can be worth it, as the CMOS-Backup style EDLC are good, I used one in my 'OG' perpetual calculator - which charged in 5 minutes or so using the original indoor solar-cell; and could run for just under an hour in low-light conditions! These are great for all those 'instant' applications; where charging with one hours notice can yield a full 8 of runtime - or high-current startup of a motor etc. They also make good spot-welder sources, and enables these and soldering-irons to be run from 'low' power such as an alkaline cell, or a solar cell. Fun fact: the EDLC is closer to a battery than a true capacitor in that it's Electrolyte (Sulfuric acid!) is involved in ionic charge transport; as opposed to a static accumulation in charges on the plates... Therefore treating them as batteries is truer to their requirements, and "C" is relatively easy to calculate; simply divide the value in Farads by 3.6 to get the value in milliamp-hours per-volt... Like batteries, at 2C the capacity is far lower than 0.1C measurements; which can be as low as 1.3 micro-ampere for the specified 47mF units, which in turn gave up to twice their rated capacity under these conditions! However, unlike the battery, these can be run down to 0.1V, and then charged to 2V - and survive as well as one used in the 1 to 1.5V range! Can the constant current discharger run at 10mA or less? Try it with 2V starting voltage after an overnight absorption charge; and run it down to 1V, which should take another night or roughly 14 hours...

I found most of these cheap ebay-super-caps to be close to 360 ... 400 F instead of 500 F. There may be different types and charges of caps available but i guess most of them is faulty production which didn't meet the specs of 360 or 400 F originals.

Out of 6 caps 2 have quite reasonable self discharge rate, in 12 hours from 2.58V to ~2.3V, 2 caps self discharged to around 1V, 1 cap to 1.5V and the last cap to 1.8V.

Cool, I love cat-culator !!

Mine arrived 3 days ago, thanks! Out of 6 caps 2 have quite reasonable self discharge rate, in 12 hours from 2.58V to ~2.3V, 2 caps self discharged to around 1V, 1 cap to 1.5V and the last cap to 1.8V.

WARNING! PIDGIN ENGLISH

They are pretty siüper ngl

Why does he talk like that???

..how about the maximum discharge current of this little darling? Would be interesting if you want to perform spot-welding, I guess

Very nice, I have been thinking of making an Arduino do this calculation, I will use your calculator instead.

most excellent video. 🥳 Could there be a safety issue on the huge supercapacitors of ever exploding even if they are installed correctly if it is a defective capacitor? 😎 Thank you.

It might be easier to discharge to e-1 (36.8%). Then the capacitance can be simply calculated (c = time / R)

Very interesting. I have bookmarked your calculator. I will have to try this with a chart recorder measuring the voltage.

What's uptalk?

please make a video about usb killer,how its works

Very nice!

I also have that same brand of supercapacitor....

nice

very gut ingliš🤣

please do some experiments with it already

❤

Thank you for calculator, you are very kind. I love your website :) I scratch my head at super caps, I do not know what is their main uses? I wonder, would they be useful in garden solar lights? I have lights I keep in window indoors and would like to replace battery with a super cap but I do not know if it would power lights for long enough or charge properly. It was nice to see your kočička in this video somewhere :) I am trying to learn some czech as I want to live there someday :) I have my heart on Vsetin where a long lost friend used to live, he is Czech.

Your cat is the prettiest one of all he technical channels!

Very interesting!

Please use the proper Greek letter μ for the micro prefix, Unicode support is pretty much universal and you already use Ω anyway...

Very cool logo on website

I have bunch of them. They start leaking after few months... pice of junk

Make cat as flash banner at the bottom, so it's more 90's. :)

A supercapacitor for a clock or thermometer? What a waste! If you want just a few milliamps (or less if it has an LCD), use significantly cheaper NiMH batteries.

Catculator 🎉😂

Nefunguje překlad. Co tam říká?

Beauty

Now use it as electric welding tool.

Oooo

How to balance super capacitor in series?

🤣🤣🤣🤣🤣