Testing a supercapacitor
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- čas přidán 6. 09. 2024
- How to measure the capacitance of a supercapacitor. Using a constant current charge and a resistive discharge methods to estimate the EDLC supercapacitor's capacitance.
The calculator:
ohmslaw.eu
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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.
neko
yeah its good no annoying popups/ads
Ohm's Law page is a genius tool to make calculations easy. I like this.
He's using I=C.∆V/∆t
Not Ohm's Law...
I think you are mistaking calculation triangles for ohms law.
Calculation triangles are a great way to remember laws that use different multiplying and dividing three parameters such as calculating distance traveled, pressure and in this context ohms law.
Very genius indeed
it's CATculator
@@Geniusinventor -
I just got this EXACT capacitor and was dreading trying to determine its true capacitance! Well timed video 🥰
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
Haha, a CatCuteLator 😻
Good that your supercapacitor turned out legit.
Thanks for the catculator. Very helpful tool. I need that regularly.
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 ;)
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
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.
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
Awesome vid man along with your catculator. Bookmarked for future use.
I’m looking forward to some rapid discharge experiments with that supercapacitor. 😈
I love your calculator so much
I hope you are going to finish your work on that bench power supply. I was enjoying that.
Your cat is the prettiest one of all he technical channels!
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
Yes, you get a differential equation where V(c) = integral(I(c))dt / C
but I(c) = (V(s) - V(c)) / R
Solve the equation, works out to V(c) = V(s) - V(s) * e^(-t / (R*C))
I(t) = (V(s) / R) * e^( -t / (R*C) )
@@liam3284 Yes that looks familia :-D, i'm really really bad at maths (Cant even remember the times tables).
A casio scientific calculator was gold to me :-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).
a tip for yout site. you used an image for background. this way dark themes dont work , put just a color.
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...
Your site is very handy but very hard to read.
Went nuts with colours and background did you?
everytime i see an cap this big (from its physical size) "the forbidden lollipop" pops up in my mind
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.
Very interesting. I have bookmarked your calculator. I will have to try this with a chart recorder measuring the voltage.
Nice video! the resistor at 7:08 is made in soviet union? I also have a few of them at home...
Great information ever 👍❤️
What a disepoint movie. Realy waiting on kaboom lol.
I hope Electroboom will like your videos
I love your Web site it has your lovely cat picture on it :0
Very nice, I have been thinking of making an Arduino do this calculation, I will use your calculator instead.
Cool, I love cat-culator !!
It might be easier to discharge to e-1 (36.8%). Then the capacitance can be simply calculated (c = time / R)
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.
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.
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.
Super Capacitors are good for high current, over short duration. They aren't so great for long discharges, as they tend to have a degree of self-discharge.
A Ni-MH (or even Ni-CD) cell is almost the perfect cell for a solar light, as you can run it right down to zero volts without harming the chemistry (they thrive on it). You will note that Solar lights have a small boost converter circuit, so they can step up the voltage to run an LED at ~3V. Over the course of the night, the circuit will keep running down to about 0.6V or less, which effectively uses almost all the energy that was stored during the day.
Very nice!
I though there were only 10 F maximun capacity super caps a 500 F blew my mind
I have 3000F super capacitor 2.7v
@@ayyadew how big is it?
I have 3000f 2.7v super capacitor I convert it to Ah =1.2
2.7v to 100mV
They are pretty siüper ngl
please make a video about usb killer,how its works
Nice website
You speak like singing with some pattern at end of sentence. Nice.
Felt like Sanskrit slokas initially.
Very interesting!
Make cat as flash banner at the bottom, so it's more 90's. :)
Eew, no! Better to use animated GIFs like a sane person!
Where are such big capacitors used??
Please use the proper Greek letter μ for the micro prefix, Unicode support is pretty much universal and you already use Ω anyway...
I decided for u, because μ felt like too much risk for too little benefit... u looks so simmilar that it's not worth the incompatibility problems. Ω is just displayed, but the u is a part of the logic (unlike Ω, the u is the prefix that is actually changing)
@@DiodeGoneWild Just specify _charset="utf8"_ to enforce Unicode support, all browsers after 2000 should have it. If your JS is ASCII-only, you can easily use Unicode characters with the _&__#code__;_ (dec) or _&__#xcode__;_ (hex) prefix, which the HTML interpreter will decode, just like named characters such as _&._ For example, μ is _&__#956__;_ = _&__#x3bc__;,_ or even the named entity _μ._ I see no risk because the units are also written in text, and the *very* few users of ancient browsers without Unicode support are used to seeing boxes or �s anyway.
Very cool logo on website
I also have that same brand of supercapacitor....
Sovietski resistor nice :D
Yeah, MLT, 2 watts power dissipation. I wonder, where it was soldered out.
nice
..how about the maximum discharge current of this little darling? Would be interesting if you want to perform spot-welding, I guess
please do some experiments with it already
❤
very gut ingliš🤣
What is name of the cat .🙂
"CatCoolEther" 😹
Nefunguje překlad. Co tam říká?
Českou angličtinou vysvětluje test čajna kondenzátoru s použitím jeho kalkulačky.
@@matysta11 To nějak nechápu.
ze ked ich kupis tak sa zda, ze je to super kup, ale ak bude uprimny tak za rok natoci novy diel kde vysvetli, ze na serioznu pracu je to odpad, ale ze za 5usd na hranie dobre
@@peterkutak Díky, tak jsem si to představoval.
catkoolator 🍭
Beauty
How to balance super capacitor in series?
Simplest form of balancer is shunt regulator/zener diode with value slightly lower than max voltage, but it will not prevent problems of imbalance during deep discharge, so careful going way too low in voltage.
@@plainedgedsaw1694 thankyou for your answer, so the problem is when the voltage polarity coming backward and the capacitor pfff 💨😁
i use bare tl431 on every capacitor (for small current limited by charger)
@@peterkutak thankyou for the answer, its a little bit pricey than zener diode but its more accurate and adjustable right?
@@widyahong i had 100pcs from china (cheap) and i use them just as 2.5V@100mA zener diode
Vref and Katode direct to +
Anode direct to -
Oooo
What's uptalk?
Now use it as electric welding tool.
a spot welder!
Kámo 🤣 trochu zapracuj na výslovnosti plís. Ic lajk jů spík lajk dys fór eprůvl
I have bunch of them. They start leaking after few months... pice of junk
i have cca 30pcs 2years some of them leaked too
No leaking yet so far with mine. had them for several years. still works.
Ordered on June 26, 2017 (1 item)
however 1 of them was wired wrong internally reverse polarity. so I contacted seller and they sent me 2 free replacement ones to replace it promptly. and its been working fine so far.
Catculator 🎉😂
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.
I was wondering the same. Super capacitors are pretty nice but generally for high current dumping. Nimh are a lot cheaper for this kind of project
i disagree, supercap is easier to work with and expected lifespan is better, price is not much higher smaller supercap is sufficient 5Fat5V(2S)
@@peterkutak I gutted out a trashed crappy solar light with a 3x3cm photovotaic cell and 600mAh AA NiMH battery. It's been powering a quartz wall clock for years. Many such low-capacity cells are in battery bins in working condition, easy to spot by their solid-color light green shrinkwrap. You can charge them from a solar cell with nothing but a diode, and 3 in series can power an ATmega.
WARNING! PIDGIN ENGLISH
Why does he talk like that???
🤣🤣🤣🤣🤣