1 Farad = 1Coulomb /Volt , i.e. the amount of charge per volt that can be held. Charge can be written as current times time C = A*s. Voltage is energy per charge, i.e. V = J/C= J/(A*s). So we get F = A*s²/J. Now, energy is force * distance, J = N*m. Force is mass times acceleration, N = kg*m/s². So J = kg*m²/s² and F = A²s⁴/(kgm²) in SI units.
The easiest way to solve physics-exercises at school: Solve, without any plan, knowledge or backthinking. Check the SI-unit of your solution. If you´ve nailed the unit, your solution-pathway was possibly the correct one, as is the solution itself (probably ;-)
Great video once again! I use the TPS63900 Buck-Boost converter in combination with a BQ25504 energy harvester and two supercaps in series in a sensor project. Works great! The TPS63900 is a relatively new buck-boost converter (1.8V to 5.5V, 75nA IQ) from TI for low power applications. Unfortunately, the chip is currently hard to get.
This TPS63900 seems to be a great chip. Together with the BQ25504 it gives a good design for an indoors light harvester like thee Enocean sensors. What kind of MCU do you use for the project?
@@jR060t About 2 years ago I made a prototype PCB with the BQ25570. It is a very good chip, but not suitable for the current design, because it has only an output current of max 100mA (the TPS63900 delivers up to 400mA -> required for NB-IoT / CAT-M1) and because with the required output voltage of 3.3V you need also at least 3.3V at the supercap (the output stage has only a buck converter). Thus only 3.3V - 5.5V can be used from the supercap's voltage range. With the TPS63900 on the other hand the full voltage range from 1.8V to 5.5V can be used (buck-boost converter), which results in about 40% more capacity.
@@Mr.Leeroy I did not yet know the NCP1402. A glance at the datasheet shows me that the Iq is 30uA, this would be too high for my design (The Iq of the TPS63900 is only 75nA) and it looks like it's a boost converter only (see also answer above)
Nice video. I found 2 usecases for those supercaps so far: UPS stuff to help between the different stages of recovering power for IT stuff, and this one: charge one up, and throw it to someone you dislike. The person will catch it, and you will have fun for a short period of time. Disclaimer: do not try this at home ;)
If you have a project that uses a battery whose inner resistance is getting higher and higher over time, a supercap can also be very helpful. Espacially if you need higher currents over a short period of time (motor, communication...) it can be used to reduce the voltage drop over the inner resistance.
@@spicybaguette7706 It is a capacitor, so yes - it acts as a buffer if/when a batterys internal resistance goes up. Unfortunately super capacitors also has a (sometimes quite) limited life span, before they also starts to degrade.
This might also work well to assist batteries used in cold environments; internal resistance of most battery chemistries goes up substantially in the cold, even for fairly new cells. A supercap in parallel could provide sufficient buffering for bursty high-current loads in outdoor projects expected to handle below freezing temperatures.
9:45 I believe you did miss something, the reason behind the hype for super capacitors is probably their cycle life/capacity. So in the long run a single super capacitor will be able to store and discharge more energy, even if batteries have a large capacity their cycle life is very limited, thus their lifespan is weak. With the constant obsession over "sustainability" this fact would be a major driving force behind the super-capacitor hype.
Excellent video as usual. Two comments: - the unit of capacitance is defined using primary SI units. As it turned out, our world as we know it can be described using only 7 different physical quantities. Sometimes their combination could look funny indeed. - Another use case for the supercaps is for keeping low power RTC ticking when the external power is removed intermittently. I think many GPS receiver modules are equipped with a supercap to allow for the warm start, especially in mobile systems in cars where the supply voltage can drop when the engine starts.
1. You are right with the SI units. But also for me they sometimes look funny. 2. I thought the GPS modules have small batteries. But I am not sure. At least I had some issues with T-Beams where the "battery" was discharged when they arrived from China and the application did not work anymore. I had to use a sketch to reset the GPS module. It seems to be a problem well known to the specialists.
Very informative video!! One application for supercapacitors which has proven very useful is in model railroading. They are used in what's called "Keep Alive" circuits which can be commercially purchased or home-built. Very often, they already come installed in newer model railroad engines. Momentary disruptions in the track voltage due to dirty track or short track gaps are not good. So the supercaps only need to supply energy for very short periods of time ... like seconds. However, the voltage requirement is higher ... typically 15 to 20 volts. If you use supercaps which are too big in farads, maybe the train engine wheels will keep going if you have engine derailment!!! My application is for an ESP32-CAM module which is built into a HO-scale boxcar for wireless train video. For this, I use two 0.330 (or 0.500) farad, 9-volt supercaps in series. This seems to work well.
Thank you for the interesting contribution and the realistic calculation. About 6 years ago, I designed grid failure detection units. First I used supercaps to deliver the energy for the transceiver informing me after power loss. Studying the data sheet of the availabe types (6 years ago), I missed any statement about lifetime and endurance of the supercaps. But there was a hint about drying out over the years. And the low temp range was limited to -20°C or so. So, I created a parallel design using lithium primary AA batteries. These are rated for 20 years shelf time typically. Perfect for that application - and cheaper and easier to use. And the temperature range for these batteries is great, too -40°C to 60°C.
My "Windwächter" which retracts the awning in case of high windspeeds uses a super cap and a solar panel. I assume they wanted it to be completely maintenance free and therefore avoided batteries. It is now nearly 10 years old and still seems to work. But I am not sure because I added my own system in parallel because I wanted it also extended with a lot of sun. AA batteries for low power applications still are a very good choice. And now with my supply of nearly unused Lithium AA batteries from my hunted weather balloons I am not short in supply. And they easily seem to work down to -60 degrees on 35'000 meters.
@@AndreasSpiess Yes, that is a very special method of "harversting" very good batteries! Im my vicinity there are no ballons landing. All captured by you!. So, I keep it easy and follow the former ETH expert Rolf Zinniker and CH "Kassensturz" (2014). Using batteries of south German discounters for general use. And these lithium ones for special use. AA are cheap and versatile. I have many zigbee motion sensors, attached and kind of integrated on/in furitures. There, I am using external AA batteries instead of the internal coin cells. Cheaper, higher capacity - and replacing batteriers without touching and re-adjustment of the sensor's position.
I have 3 Aquara sensors in the lab and after month of usage they still report nearly 100% battery. I am curious when I have to change them. A wonderful technology... And I agree with Rolf's analysis (as a former ETH student I probably should). BTW: I do not drive far over the German border for the balloons. There a few others are also chasing and I am too slow ;-)
@@AndreasSpiess Wow What is that weather balloon hunting? Are these weather balloons that some makers launch and you shot them down for spare parts? Or why do you even want to shoot it down? Is that legal to destroy other people's apparatus? :D Or is it some sort of national fun? :D BTW We too have to deal with balloons, that ruzzians launch to distract our anti-air defense.
I wish a car company would produce a super-cap gas (or diesel) hybrid. Have just a large enough super-cap bank to accelerate the car up to highway speeds several times and provide a place to dump energy during regenerative breaking. This would allow a car to use a small, light, and more fuel efficient engine. Hauling around an engine that can produce 200hp seems silly when it only takes about 30hp to drive down the highway.
A friend of mine had the idea for a car that used supercaps to start the engine. She then thought if it could be extended to accelerate the car to highway speed and it turns out the capacitance required is something silly like 3F at 450V.
I am sure we will see many new concepts in cars over the next few years. This development just started (compared to the long history of combustion engines)
I recently used a supercapacitor on an ESP32 project, in combination with a Lithium Thionyl battery. The ESP32 was used as a wireless sensor, mainly powered by the battery, but because lithium Thionyl batteries can only supply really low currents the supercapacitor was used to assist with the current delivery during wireless transmission! Was really interesting to design
@@AndreasSpiess We were building these wireless sensors that would send measurement data wirelessly to a central gateway using ESP-Now. These sensors were powered using Lithium Thionyl (didn't want to use Li-ion/Li-po for safety reasons) batteries which can only supply very low current (50mA continuous, 200mA peak). This was fine for the measuring but during sending we had to add a supercap. But to be able to use the supercap we had to limit the charging, because otherwise the charing of the capacitor would put too much strain on the battery, so we had to limi that with a resistor, then we needed a way to use the full power of the supercap while discharging (using a P-Channel MOSFET).
The measurements are taken from the temperature of the room of a house and the temperature of the water going into/coming out of the boiler for central heating. With these measurements the aim is to create a model to improve efficiency for heating of homes
@@AndreasSpiess Unfortunately not yet. It is planned to become open source (both the hardware and the software) when the development is finished. I will post a comment here with a link to the schematic and firmware for the devices!
Well you are wrong ☺️. Skeleton Technology has made super Cap configurations that for the same volume of a 10 KWh battery they deliver 100KWh with supercaps. Technology is evolving
When people ask me about super capacitors, I tell them the example that you can fly a drone for 15 seconds with them but a lithium battery lasts 15min.
Please check lithium-titanate batteries (LTO). They can fill the gap between batteries and SuperCap. Advantages: - high current charge and discharge (~10C) - temperature range (charge/discharge): -50..65 °C - >20000 cycles (80% DOD) - safe, can't burn/explode like normal Li-batteries
I compare them with LiFePo4 batteries where the low charging temperature is an advantage. Its disadvantage is the 2.4 volts where I did not see a standard charging/protection board so far.
Indeed. A mechanical storage is very close to a mechanical watch. If the bus would have used a spring to store energy it would have been exactly like the watches…
How about use with high voltage solar system to store then charge a low voltage battery bank? I have a 300v270uf cap. that will hold some butt kicking power.
why does super woman ❤️ take back seat to wonderwoman? time for her supercapacitor energy unleashed to save the universe... 👌 thanks a lot. 🙂 i like Super-caps
Great video! There are different classes of supercaps, some for low power consumption, low current leakage and long time duration, keeping an RTC for example. These are not made for high current consumption. Other classes are for the opposite, can support high current, but have a huge current leakage and will last less time. Neither are the best option to keep a higher consumption device for a long time.
Well done video. If you look into LTO batteries, they are like a hybrid between a battery and supercap, can charge/discharge quickly and high currents, but have lot more capacity and less voltage drop.
AFAIK they use chemical changes to store energy. So I would count them as batteries. They have their advantages, but their voltage (2.4 volt) is not ideal for our projects. They are probably the best choice for low temperature projects. Unfortunately I did not find standard modules for 2.4V charging or protection.
Thank you for a useful and informative video! I have been wondering about supercaps for a while now, and you hit upon all of the relevant points that I've been mulling over. You did miss one point, however, how quickly they can be recharged. Perhaps you didn't miss it per se, but rather framed it in the context of the "electric car" and thus missed some useful "temporary storage" uses in other applications.
As stated in the intro this video is focused on small projects. Making videos means to say "no" to most things. Otherwise the video would become very long ;-)
I found an usage for them: I built an UPS for my 4 servers on Raspberry Pi 4. The power supply supported by 8 x 500F super caps giving 5.4V - when 230V is gone, the voltage on these caps can keep 5A for more than 1 minute until it goes to 4.9V - this 60 seconds is more than enough to send "sudo poweroff" command to all servers. One issue: the caps are continuously leaking the current - even when fully charged - up to 0.5A from the power supply - so lots of energy is lost. On top of that: they discharge must faster the first 1V than the next 1V - but this would require boost converter - another power hungry device. After few months I decided to trash them (the caps - not the servers).
i looked into using supercapacitors for powering a esp32 running from a coin cell. i came to conclusion its simpler and easier to get a lipo or li battery - the esr you'd need for esp32 is quite low, which means there arent any nice and compact ones you can find. ... supercapacitors are very good for pulsed power applications , my little 12V 20F capacitor bank effectively can put out like 1.5 kW pulses for about 1 or 2 seconds with 100W or less of input accumulating energy. ........ in the future if we get all graphene supercapacitors it might begin to be feasible as a alternative to batteries as in theory you should be able to store incredible amounts of energy in them.
In lymens terms i think the more pressure on the caps plates the higher the charge rate they hold, Lto cells are a happy medium very temperature robust and 30000 cycles but we still dont reach the energy density of of li cells
I've done the same thought experiment with my Arduino projects some time ago as well.. the 5.5V supercaps would be perfect to replace the USB supply.. but a runtime of only a few hours or a day made it quite clear that there's no real way around LiIon cells any time soon.
I'm not sure, If you're serious. You're making a fool of yourself, if you're pretend to not know, why there are kg and meters in the equation. If I was an idiot and wanted a very simple basics explaination, I'd say, I't because Capacitors aren't meant to store energy, but are meant to store work. And that's exactly why. Seems like I'm not a complete idiot. I can understand, that you are trying to make education available to a broader spectrum. But these are fundamental physics. Everyone with a basic education beyond the 4th grade should understand the concept of work.
Andreas: shame on me for the typos! Correct text below. Andreas, you mention that capacitors store the energy in the electric field. I agree. However, chemical energy is stored in the electric field as well. It's quantum mechanics which makes the difference.
I could imagine super caps being used for those deep sleep sensors with solar panels (like you said), but for locations that you really heckin' don't wanna revisit often, since the caps don't suffer from charge/discharge cycles. Maybe a satellite in space or on the moon, for example.
I'm using supercaps in parallel to LiSOCl2 AA-Batteries (non rechargeable, e.g. SAFT LS14500, 3.6V 2.6Ah, ~3€) for powering ESP8266 (ESP-01) boards in combination with BME280 sensors. They provide p,T,h readings every 15 minutes (indoor) with deep sleep in between and battery lasts for 1.5~2 years. The supercap hereby covers the current peaks during WLAN connection until complete discharge of the battery. The setup is very simple as it does not require any voltage stabilizer. Thanks for all your great videos!
Very good summary of super capacitors. As I discovered from the FAD buoy which I took apart, video on my channel, super capacitors do have a use powering devices in some applications. Reliability is one of them and no loss of capacity. The buoy is very much a sealed for life device. The fish locating echo sounder is very high current when operating although for short bursts. I've yet to use it in a project and it came with a great solar panel. Would make an incredible solar garden light. The capacitor still has a charge in it from around 1½ years ago which I thought was incredible. Good quality capacitor but rather expensive and large.
Indeed, it would make a exclusive garden light!. I wonder why they used a super cap in this design because the temperature variations are not too big and I would assume that the device will not last forever. But obviously they trusted this tech more than the batteries and they had enough space... BTW: I see that you also are a bicycle enthusiast! I gave up with measuring power when I bought my new bike and ordered one with a built-in sensor. They came down in price.
@@AndreasSpiess I'm a bit obsessed with my automatic shifting bicycles and the power meters. Always developing the code for the shifting, currently switching to an external EEPROM. The power meter is currently providing quite successful but depends what you want out of it. It will never achieve 1% accuracy but has mostly been + - 5W of my Garmin pedals for a ride average so good enough for me. Just about to receive some costume HX711 boards for it with 116Hz sample rate.
9:40 .... I was actually thinking of this for a solar powered clock in my work's lunchroom... I have the caps, I have the clock... One cap, fully charged, will run the clock for about 23 hours... I just need to see if the solar cell can keep the cap full whenever the room is occupied (the lights go off when it is empty)... My big problem is that, Christmas Day & New Years Day my work is closed and empty, and the lights will stay off... For around (????) 24 ish hours...? I'll get around to it someday...
Parts just arrived, 2x30F 2.7V seem to pack quite a punch (fried some wires when shortened accidently). BUT I just noticed that Aliexpress Boost converters tend to have high minimum input voltage! at least 2V. The one you supplied has no tech spec on the product page; Anyone have a lead for a Low voltage boost converter capable of utilizing more juice out of the 2.7 Parallel caps?
In my company we have some applications for Ultracaps: -Windturbine Pitch System Backup. A Box the size of 1..2 bottle crate stores the energy to turn back a blade at power failure once. Monitoring the capacitance by charge/discharge a little is much easier that with batteries and the last 20 years. -Fast Frequency Response for a few seconds until diesel gensets start up. -1MW for 1s UPS power to protect a whole factory or car paintshop. -Storage to provide virtual inertia. -Once my colleages charged up some caps with the wrong polarity. Because we do not give it to customer projects, but they are still working, electrified a kickscooter with 10x3000F cells. It drives approx. 1 km, which is good to travel between office and workshop. At the moment its charged for hours with a small buck converter from a small 24V power supply, but i have qick charging solution in mind...
Nice toys you have at work. 1MW. Incredible! These are perfect applications for supercaps. Our projects, however, are very different. If you connect your scooter to one of your wind turbines it probably would charge faster, too ;-)
Self discharge current in a super capacitor is *HUGE* They can self-discharge to half energy capacity from 1 day at high temperatures to 2 weeks at low temperatures - by 'just sitting there' So, they're also SUPER-BAD at some things....
I agree. This is why I mainly saw them in combination with solar where, in winter, also the temperatures are lower. In summer they can be topped-up every day.
Hi, try this experiment: Charge a supercap to 2.7V; then wait a little while (maybe 10 minutes or so) and measure voltage again (no load). The self-discharge will have reduced the voltage. You can then compute an 'equivalent resistor' -- which I have found to be about 123K ohms. This is too much self-discharge in my opinion. Just too much leakage for anything but short-term; 1 day is just not practical, as you discuss. Perhaps a few minutes.
I did a similar experiment when I connected the buck converter to a 330k resistor. My supercap did not discharge as fast as yours (or it was bigger). But I agree: I would not propose to use them for long-term storage.
You say parallel doesn't need balancing board. So .... If I put say, 100 x 16v capacitors in parallel to assist my solar... Under heavy load fr very short bursts (eg washing machine turns on motor and off every few minutes, for eg). Is it a feasible idea or totally stupid?! Reason is 16v capacitors are really cheap and 16v is perfect for solar, and my inverter just needs a few seconds of umph when the motor starts from stationary.... Pls suggest
There’s new graphene super caps in the 18650 form factor that are on par for energy density with lithium 18650 batteries.. ranging from 3000-6000 farads ( in an 18650 form factor ) Only real issue is the lack of availability….. The real benefits are when used in conjunction with another power source ( as you said solar panels, and batteries. As they take the huge hits { high current draws } that batteries are damaged by )
I almost forgot: short circuit on 1 super cap (so only 2.7V) around 500F can seriously make a fire at home - even 16AWG wire will not survive - I tried ;-)
That's an ugly definition. Q = CV so C = Q / V where Q is measured in Amp-Seconds. C is therefor measured in Amp-Seconds per Volt (A x t / V) which is a lot more intuitive. No?
Interesting video, and clear explanation. Any electronic technician working before the digital era knew that high voltage "paper and oil" capacitors of several uF of capacity could maintain their dangerous voltage/charge/energy even for years, and that it was necessary to provide a parallel resistor to discharge them (resistance that during operation also served to balance the voltage in series configurations). An old high voltage capacitor "paper and oil", can be assimilated to a supercapacitor (the Coulomb is the measure of stored energy), only that in this case it would be necessary a DC DC step down converter to stabilize the voltage (of course, it is a theoretical speech, because involving high voltage creates many more complications). I agree that it is risky to compare batteries and capacitors, since the uses in which both can be used are few. In those cases, however, the capacitor could be the winner.
I use a super capacitor bank in my shed with some Solar panels to power some small LED lighting, only lasts a few minutes. 🙂. Temperature is a problem where I am, very hot and very cold, not suitable for any batteries (except maybe lead acid 👎).
There is no way to prevent quantum tunneling on ultra thin separation films. Unfortunately no much V boost is expected. CPU's and memory voltage is now limited by this effects.
I read that they work on different anode constructions to get a higher voltage. I agree that they cannot go smaller (for more capacity) and increase voltage. But I am no specialist. I just know that it would help a lot ;-)
Hi Andreas, Thanks for the video and the time that went into putting this together. It is a nice comprehensive comparison between the two energy storage mediums. The caps are good for pulse duty as you said, like providing high current for a short time. Car audio systems which are very high powered are a good subject. One may for instance need 10 - 30 times the output current available of the alternator only briefly. But, as the lead acid battery chemistry is not capable of supplying that kind of current, the caps are perfect. The maths you did confirms my suspicion, because I am too lazy to do the math myself, that the energy density ratio of the two storage devices is quite high. And a chemical storage device is still the best, especially if it has to be portable. The better the batteries, the bigger the issues with the chemistry though. That is the trade off. Anyhow, your video as always goes down well with a Sunday beverage. Kind regards, South Africa
I hope you are well because we do not get good news from your region ;-) I thought that car batteries have to be able to supply quite a lot of current to crank the engine. At least more than my audio system needs. Since I am no more young, there are for sure much higher powered systems available than mine...
Solar power. Pure sine wave DSP for UPS doesn't need batteries, but can do well with super capacitors with online function, which would allow solar power, whenever available, to take over smoothly.
Andreas, what was the electronic load you were using to plot overtime the voltage and current. What software and what microprocessor where you're using to do that you electronic load test???? I seen something in the description of the electronic load test but when I click on the link nothing happens. Could you give us a more description of what you used?????
There are some storage controllers with a backup battery made from supercaps. I'm using two supercaps in series to power a CMOS based clock if there is a power failure. The clock runs more than 1 hour with the caps. In some cases supercaps are fine :-)
Well, tell that to Hacktuber, I think he didn't get the memo because he's still modding anything and everything into a solar rechargeable super capacitor gizmo skeleton circuit in epoxy resin life hack that you can do at home! ;)
I recently came across someone using Lithium Ion Capacitors for a solar charger. According to Wikipedia ( en.wikipedia.org/wiki/Lithium-ion_capacitor ) they are a hybrid type of capacitor. I don't know much about them so I was curious if you know how well they work.
I never had such an LIC on my bench. But it seems to go the route I mentioned in the end: Increase the maximum voltage which is good. So we will see if we get them also for our projects in the future.
I second exploring the LIC supercapacitors. There's not alot of popular videos on this topic. I bought a 50F LIC and am getting a charging protection circuit to test how it works with solar/hand crank project. I think the ones you can buy individually can go as high as 220F, but at cheaper prices than EDLCs. They cost less per F, don't blow up like Lion batteries apparently and have a lower discharge rate. Interesting the amount of choices we have now.
supercapacitors are great for things like dashcams which just need to stay online for a few seconds to save a clip before shutting down, and operate in extreme hot/cold.
These do pair well for lithium batteries in solar setups, you will need a separate balancer for your caps and it will end up being 2 caps in series for every lithium cell you have. But they can do wonders for helping your setup handle the higher starting current demands for some applications. I'll use this in RV's where weight is a concern, and yes, you will need 2 active balancers, which anymore giving the quality issues in lithium cells is almost a must anyway.
Andreas, you mention that capacitors store the energy in the elctric field. I agrre. However, chemical energy i stired in the electric field as well. It's quantum mechanics which makes the difference.
Excellent video. One of the hyped uses of super capacitors in weight, where they are lighter than batteries for the same capacity. Still not so useful in small projects, with the possible exception of airborne projects.
Isn't the leakage a problem in ultra low power applications? I mean the self-discharge current could limit the useful time for energy storage. Maybe a year ago I came to that conclusion.
I worked in a shop that did a project that involved putting super caps in a city bus. I wish I could say it was a success but it wasn't. That was ten years ago. Hopefully, the current crop of caps are better suited for such an application. Anything to cut down on diesel smoke is worth a try.
Maybe you were ahead of time 10 years ago. Here they at least start to replace diesel buses with electrical ones. They produce much less noise (and have many more advantages). Supercaps will be an exception in this application, I think.
I am curious if this use case is possible with super capacitors: it charges up using a solar panel, boots up an esp32, sends out sensor data, then turns off fully again (not deep sleep). This could run a long time without an ageing battery.
There are lab studies and research papers that claim that in the near future 10x energy density’s increases for Super Caps are possible then the gap to batteries would shrink for 60x to 6x and open up a large variety of use cases. Especially for Stationary energy storage where space is not an issue.
You are right if the batteries would stay the same the gap would close. I expect a lot of innovation in both fields as a lot of money and brains is going into this direction. It is one of the most pressing problems for the next level of civilization... For homes it seems that LiFePo4 (LFP) already has enough cycles for 15-20 years. Peak current anyway is not a big issue for this application as we always can go to higher voltages. But to buffer peak consumption in a networks supercaps for sure will be used.
Thank you, very good video. I have seen before people using the balanced board with super caps as a car battery replacement, however I would worry about it going flat between engine starts.
What about supercap in parallel with battery for decrease internal impedance of the battery during peak current consumption (for example transmission data through WiFi)? Did you have some experience with it? Is it helps to deeper discharge battery?
Would require 2 supercaps in series to handle LiPo voltage, and would only help with an extremely small battery that couldn't handle WiFi power consumption (and at that point, why don't you spend $5 on a bigger battery instead of some complicated thing with supercaps?)
@@DmitryOrlov_dimorlus why do you need a super cap? calculate necessary capacitance as I(current in mkA) / 2*time(in seconds) and result will be Cap in mkF.
I assume it would work. But you have to pay attention that not the battery is charged in parallel to your load (using a diode for example). Otherwise, if you attach a load to this combination the voltage drops and the battery also wants to get charged by the cap...
I see maybe another application for home solar application when switching from the solar inverter to the grid (for partial offgrid setup). During this switching, electrical microcut can occured and you can loose your internet internet connexion for example. So maybe such supercapacitors can be used to overcome these microcuts during few ms for devices such as intenet box, wifi router, raspberry PI, etc...
If you have a device that varies in its current draw, such as occasional high-current event, supercaps can help keep those high-current events from batteries, which hate that kind of use. As you said, supercaps would be great for a hybrid car, because they don't wear as much as batteries. What you stated that capacitors undergo no chemical change is largely true, but electrolytic capacitors do store charge in their electrolyte. Electrolytic capacitors can develop a voltage even after being apparently discharged, which is quite a dangerous thing in high-voltage work. Sadly, electrolytic capacitors will be the failure point of most things that use them.
I always see people trying to compare batteries with super caps. As soon a load is placed on a cap the voltage goes down. This is the purpose.of a cap. High current for a brief period of time.
Andreas, good video! But I still think that makers could benefit from using supercapacitors a lot (not in all projects of course). I use a 1.5 F supercapacitor to power my "Wireless solar-powered sensor node" (basically, it is a thermometer) for almost 48 hours. It sends readings each minute (each 3 min when discharged below some level). Also, when using a bare AVR microcontroller we have quite a wide voltage range (1.8V - 5V). I can share a link if you are interested in reading about the project (the previous comment was deleted, maybe due to the link in it).
There are two aditionall benefits. 1: very high efficency, making very high power charging possible with out heat problem. 2: very simple to messure charge state
@@AndreasSpiess Well at least the last one. Say for something like a inductive power surply. Capacitors is for example used in (some) hybrid buses, where the 10% losses in the battery is to much energy to lose. Hybrid and electric cars are actually far worse than people tend to believe. A gen 1 toyota prius only retain 50% of the energy collected. Tesla S (gen1) is barley over 60%. Tesla 3 is a lot better, i don´t know the number.
Very informative video! Last 2 year I made non-stop solar machines, windowsill size. To bridge the night en cloudy weather I store the solarenergy of the 5V 60mA solarpanel in a 50F 3V supercap. One pendulum is running non-stop for 672 days on 20 micro Ampere (incl. the LCD daycounter). To convert the solar voltage to the supercap I use only a 3V low power voltage regulator. My experience with buck boosters is that they have a high start- and own power use. My advice: With less than 0.1mA use, a 50F supercap can deliver non stop power for a very, very long time, when charged by a small solarpanel. We did enter the micro- and nanoWatt era.
What voltage regulator did you use? I have a similar project to this, I Only want to power something that uses about 20uA. Also what supercap did you use?
We used large capacitors in high performance car audio to deal with high drain the batteries could not support. Although I believe some people liked it when their headlights would dim during a huge bass drop. 🤣
@@AndreasSpiess I've seen car audio systems that cost more then a new car. Windows and side panels visibly moving. Some louder then jet engines. I'm not sure if car audio as a competition caught on elsewhere. I didn't enter myself but went to watch the competition.
I just discovered Lithium-ion capacitors. At a maximum voltage of 3.8V and low self discharge as well as long cycle life I think they are really interesting for solar powered projects. Ordered a few to play around with :-)
@@AndreasSpiess I've received a 80F specimen (Fast Aliexpress delivery!) and made a little experiment: How many times can I deep-sleep cycle an ESP32 having the Lithium-Ion capacitor as the only powersource?: Turns out it manages 41 cycles of waking from deep-sleep (sleeping 30 seconds), connecting to WIFI and posting a MQTT message of the boot-count - before becoming unstable. After turn 41 the RTC-memory always return '1'. It manages to continue for another 17 cycles before stopping completely.
Then that "membrane in the middle" should be the pants of the supercap, at least if we assume that a supercap puts the underwear over the pants as many superheroes do, although I do not know if the is the positive electrode and the underwear the negative electrode or the other way around 😁
1 Farad = 1Coulomb /Volt , i.e. the amount of charge per volt that can be held. Charge can be written as current times time C = A*s. Voltage is energy per charge, i.e. V = J/C= J/(A*s). So we get F = A*s²/J. Now, energy is force * distance, J = N*m. Force is mass times acceleration, N = kg*m/s². So J = kg*m²/s² and F = A²s⁴/(kgm²) in SI units.
Thanks for the explanation! Seems logical.
It's kilogramm because this is the standard (SI) unit for mass (remember the "Urkilogramm"). vy 73
_E = 0.5 · C · U²_
wikipedia.org/wiki/Basisgr%C3%B6%C3%9Fe
The easiest way to solve physics-exercises at school: Solve, without any plan, knowledge or backthinking. Check the SI-unit of your solution. If you´ve nailed the unit, your solution-pathway was possibly the correct one, as is the solution itself (probably ;-)
Great video once again! I use the TPS63900 Buck-Boost converter in combination with a BQ25504 energy harvester and two supercaps in series in a sensor project. Works great! The TPS63900 is a relatively new buck-boost converter (1.8V to 5.5V, 75nA IQ) from TI for low power applications. Unfortunately, the chip is currently hard to get.
This TPS63900 seems to be a great chip. Together with the BQ25504 it gives a good design for an indoors light harvester like thee Enocean sensors. What kind of MCU do you use for the project?
NCP1402 is cheap and comparatively close if you are ok with fixed output
Why not use the BQ25570 or parts from other vendors like the AEM10941 which have buck boost regulators onboard?
@@jR060t About 2 years ago I made a prototype PCB with the BQ25570. It is a very good chip, but not suitable for the current design, because it has only an output current of max 100mA (the TPS63900 delivers up to 400mA -> required for NB-IoT / CAT-M1) and because with the required output voltage of 3.3V you need also at least 3.3V at the supercap (the output stage has only a buck converter). Thus only 3.3V - 5.5V can be used from the supercap's voltage range. With the TPS63900 on the other hand the full voltage range from 1.8V to 5.5V can be used (buck-boost converter), which results in about 40% more capacity.
@@Mr.Leeroy I did not yet know the NCP1402. A glance at the datasheet shows me that the Iq is 30uA, this would be too high for my design (The Iq of the TPS63900 is only 75nA) and it looks like it's a boost converter only (see also answer above)
Nice video. I found 2 usecases for those supercaps so far: UPS stuff to help between the different stages of recovering power for IT stuff, and this one: charge one up, and throw it to someone you dislike. The person will catch it, and you will have fun for a short period of time. Disclaimer: do not try this at home ;)
I am not sure about the second "use case" (if 2.7volts are enough). The 400 volt cap from the coil gun probably would create more fun ;-)
@@AndreasSpiess we used so called gold caps, but this was many years ago. I do not remember of any details except the result
The first usecase is a good idea especially for outside ups system. No maintenance as well.
Pilfer the cap from a camera flash for your second use case.
If you have a project that uses a battery whose inner resistance is getting higher and higher over time, a supercap can also be very helpful. Espacially if you need higher currents over a short period of time (motor, communication...) it can be used to reduce the voltage drop over the inner resistance.
Interesting idea. So far I usually replaced the battery because it also lost capacity.
@@AndreasSpiess I use it to get the longest battery lifetime out of primary cells. It works really well.
@@tinkerdave3157 So the supercap essentially acts as a sort of buffer?
@@spicybaguette7706 It is a capacitor, so yes - it acts as a buffer if/when a batterys internal resistance goes up.
Unfortunately super capacitors also has a (sometimes quite) limited life span, before they also starts to degrade.
This might also work well to assist batteries used in cold environments; internal resistance of most battery chemistries goes up substantially in the cold, even for fairly new cells. A supercap in parallel could provide sufficient buffering for bursty high-current loads in outdoor projects expected to handle below freezing temperatures.
9:45 I believe you did miss something, the reason behind the hype for super capacitors is probably their cycle life/capacity. So in the long run a single super capacitor will be able to store and discharge more energy, even if batteries have a large capacity their cycle life is very limited, thus their lifespan is weak. With the constant obsession over "sustainability" this fact would be a major driving force behind the super-capacitor hype.
I agree. And I thought I mentioned the fact.
Hype is the pit of science. Anyway, interesting video. Thanks.
I agree.
Excellent video as usual. Two comments:
- the unit of capacitance is defined using primary SI units. As it turned out, our world as we know it can be described using only 7 different physical quantities. Sometimes their combination could look funny indeed.
- Another use case for the supercaps is for keeping low power RTC ticking when the external power is removed intermittently. I think many GPS receiver modules are equipped with a supercap to allow for the warm start, especially in mobile systems in cars where the supply voltage can drop when the engine starts.
1. You are right with the SI units. But also for me they sometimes look funny.
2. I thought the GPS modules have small batteries. But I am not sure. At least I had some issues with T-Beams where the "battery" was discharged when they arrived from China and the application did not work anymore. I had to use a sketch to reset the GPS module. It seems to be a problem well known to the specialists.
Very informative video!! One application for supercapacitors which has proven very useful is in model railroading. They are used in what's called "Keep Alive" circuits which can be commercially purchased or home-built. Very often, they already come installed in newer model railroad engines. Momentary disruptions in the track voltage due to dirty track or short track gaps are not good. So the supercaps only need to supply energy for very short periods of time ... like seconds. However, the voltage requirement is higher ... typically 15 to 20 volts. If you use supercaps which are too big in farads, maybe the train engine wheels will keep going if you have engine derailment!!! My application is for an ESP32-CAM module which is built into a HO-scale boxcar for wireless train video. For this, I use two 0.330 (or 0.500) farad, 9-volt supercaps in series. This seems to work well.
Interesting application. I am a sponsor of such a model railroad club (morges-trains.ch) which is operated by a relative of mine :-)
Thank you for the interesting contribution and the realistic calculation. About 6 years ago, I designed grid failure detection units. First I used supercaps to deliver the energy for the transceiver informing me after power loss. Studying the data sheet of the availabe types (6 years ago), I missed any statement about lifetime and endurance of the supercaps. But there was a hint about drying out over the years. And the low temp range was limited to -20°C or so. So, I created a parallel design using lithium primary AA batteries. These are rated for 20 years shelf time typically. Perfect for that application - and cheaper and easier to use. And the temperature range for these batteries is great, too -40°C to 60°C.
My "Windwächter" which retracts the awning in case of high windspeeds uses a super cap and a solar panel. I assume they wanted it to be completely maintenance free and therefore avoided batteries. It is now nearly 10 years old and still seems to work. But I am not sure because I added my own system in parallel because I wanted it also extended with a lot of sun.
AA batteries for low power applications still are a very good choice. And now with my supply of nearly unused Lithium AA batteries from my hunted weather balloons I am not short in supply. And they easily seem to work down to -60 degrees on 35'000 meters.
@@AndreasSpiess Yes, that is a very special method of "harversting" very good batteries! Im my vicinity there are no ballons landing. All captured by you!. So, I keep it easy and follow the former ETH expert Rolf Zinniker and CH "Kassensturz" (2014). Using batteries of south German discounters for general use. And these lithium ones for special use. AA are cheap and versatile. I have many zigbee motion sensors, attached and kind of integrated on/in furitures. There, I am using external AA batteries instead of the internal coin cells. Cheaper, higher capacity - and replacing batteriers without touching and re-adjustment of the sensor's position.
I have 3 Aquara sensors in the lab and after month of usage they still report nearly 100% battery. I am curious when I have to change them. A wonderful technology... And I agree with Rolf's analysis (as a former ETH student I probably should).
BTW: I do not drive far over the German border for the balloons. There a few others are also chasing and I am too slow ;-)
@@AndreasSpiess Wow
What is that weather balloon hunting? Are these weather balloons that some makers launch and you shot them down for spare parts? Or why do you even want to shoot it down? Is that legal to destroy other people's apparatus? :D
Or is it some sort of national fun? :D
BTW We too have to deal with balloons, that ruzzians launch to distract our anti-air defense.
I wish a car company would produce a super-cap gas (or diesel) hybrid. Have just a large enough super-cap bank to accelerate the car up to highway speeds several times and provide a place to dump energy during regenerative breaking. This would allow a car to use a small, light, and more fuel efficient engine. Hauling around an engine that can produce 200hp seems silly when it only takes about 30hp to drive down the highway.
A friend of mine had the idea for a car that used supercaps to start the engine. She then thought if it could be extended to accelerate the car to highway speed and it turns out the capacitance required is something silly like 3F at 450V.
I am sure we will see many new concepts in cars over the next few years. This development just started (compared to the long history of combustion engines)
I recently used a supercapacitor on an ESP32 project, in combination with a Lithium Thionyl battery. The ESP32 was used as a wireless sensor, mainly powered by the battery, but because lithium Thionyl batteries can only supply really low currents the supercapacitor was used to assist with the current delivery during wireless transmission! Was really interesting to design
What was the challenge?
@@AndreasSpiess We were building these wireless sensors that would send measurement data wirelessly to a central gateway using ESP-Now. These sensors were powered using Lithium Thionyl (didn't want to use Li-ion/Li-po for safety reasons) batteries which can only supply very low current (50mA continuous, 200mA peak). This was fine for the measuring but during sending we had to add a supercap. But to be able to use the supercap we had to limit the charging, because otherwise the charing of the capacitor would put too much strain on the battery, so we had to limi that with a resistor, then we needed a way to use the full power of the supercap while discharging (using a P-Channel MOSFET).
The measurements are taken from the temperature of the room of a house and the temperature of the water going into/coming out of the boiler for central heating. With these measurements the aim is to create a model to improve efficiency for heating of homes
Is your diagram public domain? I am sure it would be interesting also for other viewers!
@@AndreasSpiess Unfortunately not yet. It is planned to become open source (both the hardware and the software) when the development is finished. I will post a comment here with a link to the schematic and firmware for the devices!
Well you are wrong ☺️. Skeleton Technology has made super Cap configurations that for the same volume of a 10 KWh battery they deliver 100KWh with supercaps. Technology is evolving
Good to know. Let's hope that I am wrong and technology is faster.
When people ask me about super capacitors, I tell them the example that you can fly a drone for 15 seconds with them but a lithium battery lasts 15min.
Good example!
Wonderful presentation as always. You're a valuable asset to the community and to the world at large.
😂😂 Presentation
Thank you for your nice words!
Please check lithium-titanate batteries (LTO). They can fill the gap between batteries and SuperCap. Advantages:
- high current charge and discharge (~10C)
- temperature range (charge/discharge): -50..65 °C
- >20000 cycles (80% DOD)
- safe, can't burn/explode like normal Li-batteries
I compare them with LiFePo4 batteries where the low charging temperature is an advantage. Its disadvantage is the 2.4 volts where I did not see a standard charging/protection board so far.
I found useless 2.7v 2.2f supercapacitor, just glowed up red led for few minutes and spend cost of two 3.7v lithium batteries
They do not store a lot of energy, you are right.
Like the bus, think Switzerland also used gyro busses in the 60’ who else than professional watch makers would do that. :-)
Indeed. A mechanical storage is very close to a mechanical watch. If the bus would have used a spring to store energy it would have been exactly like the watches…
How about use with high voltage solar system to store then charge a low voltage battery bank? I have a 300v270uf cap. that will hold some butt kicking power.
Maybe needed if you only use small batteries which cannot support the full current of the solar panels.
why does super woman ❤️ take back seat to wonderwoman? time for her supercapacitor energy unleashed to save the universe... 👌 thanks a lot. 🙂 i like Super-caps
:-))
Great video! There are different classes of supercaps, some for low power consumption, low current leakage and long time duration, keeping an RTC for example. These are not made for high current consumption. Other classes are for the opposite, can support high current, but have a huge current leakage and will last less time. Neither are the best option to keep a higher consumption device for a long time.
Thank you for the additional information!
Thanks for all the informative videos i've learned a lot, danke schön Andreas!
You are welcome!
How funny that super capacitors have super small capacity :)
Indeed, the capacity is quite small compared with batteries.
Well done video. If you look into LTO batteries, they are like a hybrid between a battery and supercap, can charge/discharge quickly and high currents, but have lot more capacity and less voltage drop.
AFAIK they use chemical changes to store energy. So I would count them as batteries. They have their advantages, but their voltage (2.4 volt) is not ideal for our projects. They are probably the best choice for low temperature projects. Unfortunately I did not find standard modules for 2.4V charging or protection.
Thank you for a useful and informative video! I have been wondering about supercaps for a while now, and you hit upon all of the relevant points that I've been mulling over. You did miss one point, however, how quickly they can be recharged. Perhaps you didn't miss it per se, but rather framed it in the context of the "electric car" and thus missed some useful "temporary storage" uses in other applications.
As stated in the intro this video is focused on small projects. Making videos means to say "no" to most things. Otherwise the video would become very long ;-)
@@AndreasSpiess Right, but that is one of the great benefits they have over batteries.
What about use in conjunktion with lithium for surge protection
I do not understand what you mean :-(
I found an usage for them: I built an UPS for my 4 servers on Raspberry Pi 4. The power supply supported by 8 x 500F super caps giving 5.4V - when 230V is gone, the voltage on these caps can keep 5A for more than 1 minute until it goes to 4.9V - this 60 seconds is more than enough to send "sudo poweroff" command to all servers. One issue: the caps are continuously leaking the current - even when fully charged - up to 0.5A from the power supply - so lots of energy is lost. On top of that: they discharge must faster the first 1V than the next 1V - but this would require boost converter - another power hungry device.
After few months I decided to trash them (the caps - not the servers).
I once made a video where I used a much smaller cap for the same purpose. But only one Raspberry, of course.
@@AndreasSpiess I know, I saw, it pushed me to do it on a bigger scale so thank you
great job busting through the hype Andreas :)
Thank you!
Nice and helpful video
Thank you!
i looked into using supercapacitors for powering a esp32 running from a coin cell. i came to conclusion its simpler and easier to get a lipo or li battery - the esr you'd need for esp32 is quite low, which means there arent any nice and compact ones you can find. ... supercapacitors are very good for pulsed power applications , my little 12V 20F capacitor bank effectively can put out like 1.5 kW pulses for about 1 or 2 seconds with 100W or less of input accumulating energy. ........ in the future if we get all graphene supercapacitors it might begin to be feasible as a alternative to batteries as in theory you should be able to store incredible amounts of energy in them.
Thank you for sharing your experience. And I am sure we will get a lot of innovation in energy storage over the next years. It is needed...
In lymens terms i think the more pressure on the caps plates the higher the charge rate they hold, Lto cells are a happy medium very temperature robust and 30000 cycles but we still dont reach the energy density of of li cells
Absolutely love the mini hand and glove.
AFAIK LTOs change their chemical structure and I would count them into batteries. But maybe I am wrong.
I've done the same thought experiment with my Arduino projects some time ago as well.. the 5.5V supercaps would be perfect to replace the USB supply.. but a runtime of only a few hours or a day made it quite clear that there's no real way around LiIon cells any time soon.
Thank you for sharing your experience!
I'm not sure, If you're serious. You're making a fool of yourself, if you're pretend to not know, why there are kg and meters in the equation. If I was an idiot and wanted a very simple basics explaination, I'd say, I't because Capacitors aren't meant to store energy, but are meant to store work. And that's exactly why. Seems like I'm not a complete idiot.
I can understand, that you are trying to make education available to a broader spectrum. But these are fundamental physics. Everyone with a basic education beyond the 4th grade should understand the concept of work.
As always - Extremely effective video, typically Swiss. Thank you for the noble work of sharing your knowledge.
My pleasure!
Andreas: shame on me for the typos! Correct text below.
Andreas, you mention that capacitors store the energy in the electric field. I agree. However, chemical energy is stored in the electric field as well. It's quantum mechanics which makes the difference.
I could imagine super caps being used for those deep sleep sensors with solar panels (like you said), but for locations that you really heckin' don't wanna revisit often, since the caps don't suffer from charge/discharge cycles. Maybe a satellite in space or on the moon, for example.
I do not know if they are used in satellites. But a few properties of the super caps seem to be ideal for that purpose.
I like supercapacitors, they would make great fires in shot cuts if used in cars it would be like instant cremation
I'm using supercaps in parallel to LiSOCl2 AA-Batteries (non rechargeable, e.g. SAFT LS14500, 3.6V 2.6Ah, ~3€) for powering ESP8266 (ESP-01) boards in combination with BME280 sensors. They provide p,T,h readings every 15 minutes (indoor) with deep sleep in between and battery lasts for 1.5~2 years. The supercap hereby covers the current peaks during WLAN connection until complete discharge of the battery. The setup is very simple as it does not require any voltage stabilizer. Thanks for all your great videos!
Thank you for sharing your project. A good use for such a cap because these batteries have a high internal resistance.
Very good summary of super capacitors. As I discovered from the FAD buoy which I took apart, video on my channel, super capacitors do have a use powering devices in some applications.
Reliability is one of them and no loss of capacity. The buoy is very much a sealed for life device.
The fish locating echo sounder is very high current when operating although for short bursts.
I've yet to use it in a project and it came with a great solar panel. Would make an incredible solar garden light.
The capacitor still has a charge in it from around 1½ years ago which I thought was incredible.
Good quality capacitor but rather expensive and large.
Indeed, it would make a exclusive garden light!. I wonder why they used a super cap in this design because the temperature variations are not too big and I would assume that the device will not last forever. But obviously they trusted this tech more than the batteries and they had enough space...
BTW: I see that you also are a bicycle enthusiast! I gave up with measuring power when I bought my new bike and ordered one with a built-in sensor. They came down in price.
@@AndreasSpiess I'm a bit obsessed with my automatic shifting bicycles and the power meters. Always developing the code for the shifting, currently switching to an external EEPROM.
The power meter is currently providing quite successful but depends what you want out of it. It will never achieve 1% accuracy but has mostly been + - 5W of my Garmin pedals for a ride average so good enough for me. Just about to receive some costume HX711 boards for it with 116Hz sample rate.
only if you want to get fried weekly
???
9:40 .... I was actually thinking of this for a solar powered clock in my work's lunchroom... I have the caps, I have the clock... One cap, fully charged, will run the clock for about 23 hours... I just need to see if the solar cell can keep the cap full whenever the room is occupied (the lights go off when it is empty)...
My big problem is that, Christmas Day & New Years Day my work is closed and empty, and the lights will stay off... For around (????) 24 ish hours...?
I'll get around to it someday...
I assume you would need to dimension the cap accordingly. Like the batteries in a solar powered outside project...
Parts just arrived, 2x30F 2.7V seem to pack quite a punch (fried some wires when shortened accidently). BUT I just noticed that Aliexpress Boost converters tend to have high minimum input voltage! at least 2V.
The one you supplied has no tech spec on the product page; Anyone have a lead for a Low voltage boost converter capable of utilizing more juice out of the 2.7 Parallel caps?
The typical energy harvesting chips are made to start at very low voltages.
In my company we have some applications for Ultracaps:
-Windturbine Pitch System Backup. A Box the size of 1..2 bottle crate stores the energy to turn back a blade at power failure once. Monitoring the capacitance by charge/discharge a little is much easier that with batteries and the last 20 years.
-Fast Frequency Response for a few seconds until diesel gensets start up.
-1MW for 1s UPS power to protect a whole factory or car paintshop.
-Storage to provide virtual inertia.
-Once my colleages charged up some caps with the wrong polarity. Because we do not give it to customer projects, but they are still working, electrified a kickscooter with 10x3000F cells. It drives approx. 1 km, which is good to travel between office and workshop. At the moment its charged for hours with a small buck converter from a small 24V power supply, but i have qick charging solution in mind...
Nice toys you have at work. 1MW. Incredible! These are perfect applications for supercaps. Our projects, however, are very different.
If you connect your scooter to one of your wind turbines it probably would charge faster, too ;-)
Self discharge current in a super capacitor is *HUGE*
They can self-discharge to half energy capacity from 1 day at high temperatures to 2 weeks at low temperatures - by 'just sitting there'
So, they're also SUPER-BAD at some things....
I agree. This is why I mainly saw them in combination with solar where, in winter, also the temperatures are lower. In summer they can be topped-up every day.
Hi, try this experiment: Charge a supercap to 2.7V; then wait a little while (maybe 10 minutes or so) and measure voltage again (no load). The self-discharge will have reduced the voltage. You can then compute an 'equivalent resistor' -- which I have found to be about 123K ohms. This is too much self-discharge in my opinion. Just too much leakage for anything but short-term; 1 day is just not practical, as you discuss. Perhaps a few minutes.
I did a similar experiment when I connected the buck converter to a 330k resistor. My supercap did not discharge as fast as yours (or it was bigger). But I agree: I would not propose to use them for long-term storage.
You say parallel doesn't need balancing board. So .... If I put say, 100 x 16v capacitors in parallel to assist my solar... Under heavy load fr very short bursts (eg washing machine turns on motor and off every few minutes, for eg). Is it a feasible idea or totally stupid?!
Reason is 16v capacitors are really cheap and 16v is perfect for solar, and my inverter just needs a few seconds of umph when the motor starts from stationary.... Pls suggest
I suggest to make the calculation on how much energy those caps can store compared with the consumption. I fear it will not be a lot.
Good and well-founded answer. Thank you for the video.👍🏻
Glad it was helpful!
There’s new graphene super caps in the 18650 form factor that are on par for energy density with lithium 18650 batteries.. ranging from 3000-6000 farads ( in an 18650 form factor )
Only real issue is the lack of availability…..
The real benefits are when used in conjunction with another power source ( as you said solar panels, and batteries. As they take the huge hits { high current draws } that batteries are damaged by )
I for sure will test them if they become available at reasonable prices...
I almost forgot: short circuit on 1 super cap (so only 2.7V) around 500F can seriously make a fire at home - even 16AWG wire will not survive - I tried ;-)
Hopefully the cap has bigger wires inside. Otherwise it is damaged, too ;-)
Perfect spanish translation. Felicitaciones!!! Saludos, Carlos, Buenos Aires.
The translation is done by Luciana, an Argentinean lady...
That's an ugly definition. Q = CV so C = Q / V where Q is measured in Amp-Seconds. C is therefor measured in Amp-Seconds per Volt (A x t / V) which is a lot more intuitive. No?
I agree!
Interesting video, and clear explanation. Any electronic technician working before the digital era knew that high voltage "paper and oil" capacitors of several uF of capacity could maintain their dangerous voltage/charge/energy even for years, and that it was necessary to provide a parallel resistor to discharge them (resistance that during operation also served to balance the voltage in series configurations). An old high voltage capacitor "paper and oil", can be assimilated to a supercapacitor (the Coulomb is the measure of stored energy), only that in this case it would be necessary a DC DC step down converter to stabilize the voltage (of course, it is a theoretical speech, because involving high voltage creates many more complications). I agree that it is risky to compare batteries and capacitors, since the uses in which both can be used are few. In those cases, however, the capacitor could be the winner.
As you describe, each technology has its use cases where they "shine".
I use a super capacitor bank in my shed with some Solar panels to power some small LED lighting, only lasts a few minutes. 🙂. Temperature is a problem where I am, very hot and very cold, not suitable for any batteries (except maybe lead acid 👎).
Lead acid are still a good choice for harsh conditions. LiFePo4 seem also be ok if you do not charge them below 0 degrees C.
There is no way to prevent quantum tunneling on ultra thin separation films. Unfortunately no much V boost is expected. CPU's and memory voltage is now limited by this effects.
I read that they work on different anode constructions to get a higher voltage. I agree that they cannot go smaller (for more capacity) and increase voltage. But I am no specialist. I just know that it would help a lot ;-)
Hey Andrea, do you think if electrical appliances were built with tantalum caps ... they would last longer ??
I do not know. But I know that tantalums are expensive...
Hi Andreas,
Thanks for the video and the time that went into putting this together.
It is a nice comprehensive comparison between the two energy storage mediums.
The caps are good for pulse duty as you said, like providing high current for a short time.
Car audio systems which are very high powered are a good subject.
One may for instance need 10 - 30 times the output current available of the alternator only briefly.
But, as the lead acid battery chemistry is not capable of supplying that kind of current, the caps are perfect.
The maths you did confirms my suspicion, because I am too lazy to do the math myself, that the energy density ratio of the two storage devices is quite high.
And a chemical storage device is still the best, especially if it has to be portable.
The better the batteries, the bigger the issues with the chemistry though.
That is the trade off.
Anyhow, your video as always goes down well with a Sunday beverage.
Kind regards,
South Africa
I hope you are well because we do not get good news from your region ;-) I thought that car batteries have to be able to supply quite a lot of current to crank the engine. At least more than my audio system needs. Since I am no more young, there are for sure much higher powered systems available than mine...
Solar power. Pure sine wave DSP for UPS doesn't need batteries, but can do well with super capacitors with online function, which would allow solar power, whenever available, to take over smoothly.
Interesting idea!
Now it makes sense why Supercapacitors aren't ubiquitous in electric cars - you'd need hundreds of them to operate at 400+ volts!
And the car would become rather big, I assume.
Andreas, what was the electronic load you were using to plot overtime the voltage and current.
What software and what microprocessor where you're using to do that you electronic load test????
I seen something in the description of the electronic load test but when I click on the link nothing happens.
Could you give us a more description of what you used?????
Maybe you try the link again. I replaced it (and make sure you do not use an ad-blocker)
There are some storage controllers with a backup battery made from supercaps.
I'm using two supercaps in series to power a CMOS based clock if there is a power failure. The clock runs more than 1 hour with the caps.
In some cases supercaps are fine :-)
Nice project! I also used such a setup to safely power-down a Raspberry at power failure.
everytime I try to use supercaps, their charging time ... well ... it ... takes ... forever ... Spend more time charging them than using them.
Strange. Maybe your power supply is not very strong. Or your supercaps are defective.
Well, tell that to Hacktuber, I think he didn't get the memo because he's still modding anything and everything into a solar rechargeable super capacitor gizmo skeleton circuit in epoxy resin life hack that you can do at home! ;)
Maybe he learned to profit from the hype? Very important on TH-cam. Maybe I am too stupid or too "engineer" to accept it ;-)
Stirling Engine - Supercapacitor - Electric Motor/Generator. Would this be a good combination?
I do not know. The sterling engine is more on the mechanical side...
I recently came across someone using Lithium Ion Capacitors for a solar charger. According to Wikipedia ( en.wikipedia.org/wiki/Lithium-ion_capacitor ) they are a hybrid type of capacitor. I don't know much about them so I was curious if you know how well they work.
I never had such an LIC on my bench. But it seems to go the route I mentioned in the end: Increase the maximum voltage which is good. So we will see if we get them also for our projects in the future.
I second exploring the LIC supercapacitors. There's not alot of popular videos on this topic. I bought a 50F LIC and am getting a charging protection circuit to test how it works with solar/hand crank project. I think the ones you can buy individually can go as high as 220F, but at cheaper prices than EDLCs. They cost less per F, don't blow up like Lion batteries apparently and have a lower discharge rate. Interesting the amount of choices we have now.
supercapacitors are great for things like dashcams which just need to stay online for a few seconds to save a clip before shutting down, and operate in extreme hot/cold.
True. In another video, I also used one to keep the voltage of a Raspberry high for a save shutdown.
These do pair well for lithium batteries in solar setups, you will need a separate balancer for your caps and it will end up being 2 caps in series for every lithium cell you have. But they can do wonders for helping your setup handle the higher starting current demands for some applications.
I'll use this in RV's where weight is a concern, and yes, you will need 2 active balancers, which anymore giving the quality issues in lithium cells is almost a must anyway.
Indeed, they are perfect if you need high initial currents.
Andreas, you mention that capacitors store the energy in the elctric field. I agrre. However, chemical energy i stired in the electric field as well. It's quantum mechanics which makes the difference.
Thank you for the update. I have no clue about quantum mechanics. To "high" for me ;-)
Excellent video. One of the hyped uses of super capacitors in weight, where they are lighter than batteries for the same capacity. Still not so useful in small projects, with the possible exception of airborne projects.
I never compared the weight of supercaps with batteries. So good to know.
1:29 really, must do better. Write to the 'Othias' and request a proper 'patented plastic pokey hand' ;-) ... subscribed
Welcome aboard the channel!
Isn't the leakage a problem in ultra low power applications? I mean the self-discharge current could limit the useful time for energy storage. Maybe a year ago I came to that conclusion.
You are right. They are not good for long-term usage. A few hours seem to be ok, though.
the best battery for long lasting mcu device is RTG plutonium battery, the one that used to power a pacemaker XD
Plutonium is always a potent source of power. Not only for electrical power ;-)
Supercaps are very handy, though, for maintaining power on an RPi on an unexpected power supply loss, long enough for a clean OS shutdown.
I agree and I even made a video about it in the past...
@@AndreasSpiess ....and it was very clever, thanks Andreas.
I worked in a shop that did a project that involved putting super caps in a city bus. I wish I could say it was a success but it wasn't. That was ten years ago. Hopefully, the current crop of caps are better suited for such an application. Anything to cut down on diesel smoke is worth a try.
Maybe you were ahead of time 10 years ago. Here they at least start to replace diesel buses with electrical ones. They produce much less noise (and have many more advantages). Supercaps will be an exception in this application, I think.
I recall a teacher saying that a 1 Farad capacitor would be as large as a telephone box (UK)! 40 years later and they are clearly much, much, smaller.
Definitively! Also a few other things became smaller during this time. Just my belly became bigger ;-)
SUPER CAPS can provide massive amounts of current if called on.
You are right.
I am curious if this use case is possible with super capacitors: it charges up using a solar panel, boots up an esp32, sends out sensor data, then turns off fully again (not deep sleep). This could run a long time without an ageing battery.
This is possible. I did it for my "Amazon Dash Button" project. The only question is: How to switch the MCU on (I used a mechanical switch)
You skipped over the fact capacitors can charge up much faster than batteries. That's a big part of the hype I would think.
You are right. But this is not too important for the use case presented in this video.
There are lab studies and research papers that claim that in the near future 10x energy density’s increases for Super Caps are possible then the gap to batteries would shrink for 60x to 6x and open up a large variety of use cases. Especially for Stationary energy storage where space is not an issue.
You are right if the batteries would stay the same the gap would close. I expect a lot of innovation in both fields as a lot of money and brains is going into this direction. It is one of the most pressing problems for the next level of civilization...
For homes it seems that LiFePo4 (LFP) already has enough cycles for 15-20 years. Peak current anyway is not a big issue for this application as we always can go to higher voltages.
But to buffer peak consumption in a networks supercaps for sure will be used.
Awesome! Yep Though they are really cool, they are mostly useless and a battery of much bigger capacity can replace them easily
As most other things: They have advantages and disadvantages...
Thank you, very good video. I have seen before people using the balanced board with super caps as a car battery replacement, however I would worry about it going flat between engine starts.
Because they are hyped they provide good titles for TH-cam videos ;-) But, as you say, probably not a good board.
What about supercap in parallel with battery for decrease internal impedance of the battery during peak current consumption (for example transmission data through WiFi)? Did you have some experience with it? Is it helps to deeper discharge battery?
Would require 2 supercaps in series to handle LiPo voltage, and would only help with an extremely small battery that couldn't handle WiFi power consumption (and at that point, why don't you spend $5 on a bigger battery instead of some complicated thing with supercaps?)
@@Phoen1x883 There is 5V supercaps, but this is exactly my question, I don't know if it makes sense or not.
@@DmitryOrlov_dimorlus why do you need a super cap? calculate necessary capacitance as I(current in mkA) / 2*time(in seconds) and result will be Cap in mkF.
I assume it would work. But you have to pay attention that not the battery is charged in parallel to your load (using a diode for example). Otherwise, if you attach a load to this combination the voltage drops and the battery also wants to get charged by the cap...
Thanks Andreas, I'm hoping for a supercap boost in my next e-car in Canada.
I read that the Tesla Roadster aims for 1.2 sec from 0-60miles/h. I do not know if they use supercaps...
Capacitors last 2 seconds, batteries last 20 hours. And lithium ion battery, 5 years.
Maybe. All depends on the use case and the size of the energy storage device. I agree that capacitors have much lower Wh/kg than batteries.
I see maybe another application for home solar application when switching from the solar inverter to the grid (for partial offgrid setup). During this switching, electrical microcut can occured and you can loose your internet internet connexion for example. So maybe such supercapacitors can be used to overcome these microcuts during few ms for devices such as intenet box, wifi router, raspberry PI, etc...
Good idea!
SMA uses large capacitors to do daytime backup without batteries. They're not supercaps, however, just large high voltage electrolytics.
If you have a device that varies in its current draw, such as occasional high-current event, supercaps can help keep those high-current events from batteries, which hate that kind of use. As you said, supercaps would be great for a hybrid car, because they don't wear as much as batteries.
What you stated that capacitors undergo no chemical change is largely true, but electrolytic capacitors do store charge in their electrolyte. Electrolytic capacitors can develop a voltage even after being apparently discharged, which is quite a dangerous thing in high-voltage work. Sadly, electrolytic capacitors will be the failure point of most things that use them.
I agree with all your comments.
@@AndreasSpiess , well, I am flattered. Thank you.
Quite some people add super capacitors to their car battery, just for they have all power available for car starting in cold conditions.
Maybe this is needed in very cold climate. For sure a good application.
Awesome lesson Adreas! Thanks a lot for your class!
My pleasure!
I always see people trying to compare batteries with super caps. As soon a load is placed on a cap the voltage goes down. This is the purpose.of a cap. High current for a brief period of time.
I agree.
Very good job.👏
Thank you!
Usualy people who does not know what they are talking about are asking this question.
Great video as ussual 👍
Now all should know ;-)
Andreas, good video! But I still think that makers could benefit from using supercapacitors a lot (not in all projects of course).
I use a 1.5 F supercapacitor to power my "Wireless solar-powered sensor node" (basically, it is a thermometer) for almost 48 hours. It sends readings each minute (each 3 min when discharged below some level). Also, when using a bare AVR microcontroller we have quite a wide voltage range (1.8V - 5V).
I can share a link if you are interested in reading about the project (the previous comment was deleted, maybe due to the link in it).
Interesting! You have to send the link via Facebook messenger or twitter. TH-cam deletes links :-(
@@AndreasSpiess, I've sent it via FB. It also can get easily googled by the name "Wireless solar-powered sensor node".
This could work in some applications ,like a led solar garden light. The problem is the cost.
I agree.
Kg & m & s & A because they are 4 of the 7 base units of the international system. Everything else is derived units.
You are right. But still, it is weird for me...
There are two aditionall benefits.
1: very high efficency, making very high power charging possible with out heat problem.
2: very simple to messure charge state
I agree. Both are not very critical for small projects, though.
@@AndreasSpiess Well at least the last one. Say for something like a inductive power surply.
Capacitors is for example used in (some) hybrid buses, where the 10% losses in the battery is to much energy to lose.
Hybrid and electric cars are actually far worse than people tend to believe. A gen 1 toyota prius only retain 50% of the energy collected. Tesla S (gen1) is barley over 60%. Tesla 3 is a lot better, i don´t know the number.
Great video! Thanks 😀
Glad you liked it! 73.
Very informative video! Last 2 year I made non-stop solar machines, windowsill size. To bridge the night en cloudy weather I store the solarenergy of the 5V 60mA solarpanel in a 50F 3V supercap. One pendulum is running non-stop for 672 days on 20 micro Ampere (incl. the LCD daycounter). To convert the solar voltage to the supercap I use only a 3V low power voltage regulator. My experience with buck boosters is that they have a high start- and own power use. My advice: With less than 0.1mA use, a 50F supercap can deliver non stop power for a very, very long time, when charged by a small solarpanel. We did enter the micro- and nanoWatt era.
Thank you for sharing your experience. Seems to be a good project!
What voltage regulator did you use? I have a similar project to this, I Only want to power something that uses about 20uA. Also what supercap did you use?
@@elpechos The voltage regulator is a 3 pin 3V LP2950 low self power use. As supercap I use a 50F 3V one, charged with a 5V 60mA solarpanel.
@@Bertoaus Thanks for that
We used large capacitors in high performance car audio to deal with high drain the batteries could not support. Although I believe some people liked it when their headlights would dim during a huge bass drop. 🤣
Interesting. I always thought that the car batteries are made for large currents. But obviously you had a more powerful audio system ;-)
@@AndreasSpiess I've seen car audio systems that cost more then a new car. Windows and side panels visibly moving. Some louder then jet engines. I'm not sure if car audio as a competition caught on elsewhere. I didn't enter myself but went to watch the competition.
Yes, this was very helpful. Now, what's a capacitor? 😊
:-)
I just discovered Lithium-ion capacitors. At a maximum voltage of 3.8V and low self discharge as well as long cycle life I think they are really interesting for solar powered projects. Ordered a few to play around with :-)
Good decision. I show one of them in my mailbag video...
@@AndreasSpiess I've received a 80F specimen (Fast Aliexpress delivery!) and made a little experiment:
How many times can I deep-sleep cycle an ESP32 having the Lithium-Ion capacitor as the only powersource?:
Turns out it manages 41 cycles of waking from deep-sleep (sleeping 30 seconds), connecting to WIFI and posting a MQTT message of the boot-count - before becoming unstable.
After turn 41 the RTC-memory always return '1'. It manages to continue for another 17 cycles before stopping completely.
Then that "membrane in the middle" should be the pants of the supercap, at least if we assume that a supercap puts the underwear over the pants as many superheroes do, although I do not know if the is the positive electrode and the underwear the negative electrode or the other way around 😁
:-))
Why is it so difficult to find a cap battery BMS and charger project?
Probably because supercaps are not good batteries and very expensive...