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Yes you read that correctly - 10Farad capacitor. This small cap can be charged up and then slowly dissipated running an entire system for hours. Combine two in series for 5F/5V. Do not over voltage or reverse polarize these capacitors.
- 13mm x 33.5mm
Super Capacitor - 10F/2.5V Product Help and Resources
Capacitors
June 19, 2013
Learn about all things capacitors. How they're made. How they work. How they look. Types of capacitors. Series/parallel capacitors. Capacitor applications.
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Customer Reviews
4.7 out of 5
Based on 3 ratings:
4 of 4 found this helpful:
Worked out well
Used 4 of these to replace a backup battery in an old clock radio. In the course of changing it from a battery to a capacitor i found that the original Chinese workers forgot to add a diode. So that is why my 9v batteries were dying so quickly. The 7v AC was draining the 9v DC. In the end i left the caps anyway. Now i never have to replace that stupid battery ever again. Of course for longevity a battery would be better.
1 of 1 found this helpful:
A very nice supercap for a good price.
From what I've tested of it, it would make for a very nice capacitor bank. I intend to purchase a few more for that purpose. The one I have seems to be very high quality.
For a 10F cap, it is very small in size. I purchased a few 1.5F caps a week later, and size wise, they are much larger. (if I compared them mass per Ferad, they would be twice as large.)
This specific cap I purchased I intend to use in a power supply for a headphone amp.
This capacitor holds about 116mAh at 2.5 volts which is about 0.29 joules. It's over two times larger (volume-wise) than a 3.7v 110mAh lipo battery (https://www.sparkfun.com/products/731), which holds approximately the same amount of energy, about 0.28 joules. Just some quick factoids. Please correct me if I'm wrong :D
You think that the 10F is a lot, Look at the 120F one in the picture in data sheet.
I found one here. Enjoy.
EDIT: It appears that Mouser and Digikey stock them, but good luck finding some that are actually in stock!
I once saw one (in person! I had to resist buying it) that was somewhere around 1,000F. Wow.
My dad has a 3000F Capacitor, and it is huge! That thing will incinerate any aluminum foil that touches both contacts XD
These are tougher than I expected. I am using two as a makeshift "UPS" for a Chumby mainboard, powered by a 5.0V mini-USB phone charger, and it had proved its workability a couple of times as I had moved the power wiring around with no reboots. This morning I discovered I had wired one of the caps backwards ($foo late-night wiring jobs!), and expected that the backwards cap would be dead. But no... I just discharged it, rewired it forwards, recharged, and the whole hack still works correctly.
I'm quite happy that the caps stood up to such abuse!
This is because when you wire two caps back to back with polarity reversed (at least this is what my electronics fundamentals book taught me), so either + to + with - outwards, or vice versa, it will act as a non-polarized capacitor with half the capacitance (just like a regular series connection). So that's why there wasn't a problem. Trust me, if you connected one backwards it would have gone off like a bomb.
It may act like a non-polarized capacitor (i.e. in its interaction with the rest of the circuit), but each of the two capacitors it's composed of is still polarized.
For people experimenting with these super capacitors and using them to power equipment. Please keep in mind that a capacitor is not a battery. You do NOT "get" 7.5V by stringing 3 of them together as you would with a battery. A capacitor is basically "dead" until it is charged. And unlike a battery, it (mostly) linearly charges to whatever voltage it is supplied with by the end of its charge cycle. It has no charge of its own like a battery, so you don't "get" voltage by putting them together. What you get is the capability to safely operate at the stated operating voltage. You could charge to any lesser voltage, and should certainly consider doing so as was mentioned in other threads. You would want at least 3 or 4 caps in series to safely operate at 5 volts, not 7.5. And charging is certainly important with these extremely high farad capacitors, as the capacitor is a virtual dead short when voltage is first applied. You need current limiting. Probably best to use a current-limited power supply which automatically reduces the voltage when rated current is exceeded. And through a suitable diode for safety of the power supply. This kind of power supply will operate in a "constant current" mode until the set voltage is reached at which time it will revert to "constant voltage" and continue charging, reducing the current supplied as needed.
And even though it's tempting, avoid shorting the terminals of a fully charged capacitor. It could result in the discharge of thousands of amps. You know the flash tubes used for camera flash? A moderately powered one uses about a 250 or 300 MICRO-farad (.0003 farad) capacitor. When it flashes at full power, it dumps over 100 amps through the flash tube for about a millisecond or less. Imagine what your 10 FARAD capacitor will do when shorted. And the flash tube is by no means a direct short either.
It's always fun to "play around" with electronic/electrical stuff. But do yourselves a favor and get some books on basic electricity and learn what it is you are playing with. My father instilled that principal in me over 50 years ago and I am forever in his debt (RIP).
These aren't that dangerous electrically. If your skin is (extremely) wet or broken, its resistance might reach 1,000 ohms (this is seen as the minimum human skin resistance). Using Ohm's law, we can calculate that about 2.5mA would flow through your skin at 2.5V. You could lick a fully charged supercap and feel nothing.
These would be dangerous to pop though. Because their pop could be a fireball, or shrapnel flying around the room.
Every time someone suggests doing something stupid, it encourages some people to test the limits. Capacitors can kill you when charged. So the smart thing is always practice safe habits and then no one gets hurt. Kids in particular don't always practice safety.
I'm pretty sure they meant general shorts, not just with the skin.
And here a nooby question (new to electronics)... I see these are rated for 2.5V but I plan using them in a 5V circuit, will that be okay as long as I connect the two of them in series?
Don't forget that series capacitors decrease the total capacitance (opposite for resistors).
A good engineering practice is using caps rated for double the circuit voltage. Go with 4 caps in a series for a total of 10V instead of 2 for 5V. The reasons - possible power supply noise and inconsistency in capacitor quality. Most caps rated at 2.5V will handle that voltage safely. Few will be able to handle higher voltages. Few will burn out way before reaching the stated value. Play safe and go "double the value".
The only reason to go with caps rated closely to the circuit voltage is to save physical space, but if you ask me, there's always room for an extra cap, even if you have to plant it outside with an electric tape.
Big manufacturers sometimes go cheap on the caps and end up with "leaky" electronics. Samsung used to be notorious for putting cheap caps into their LCD's to save something like $5 per unit. I ended up resurrecting tons of those.
Used to be? They still are and why I will not touch a Samsung LCD anything from them.
I did the research and found out my case was not an isolated Samsung cap issue and that the issue is still there even in 2012.
I decided to charge one of those up to ~2.25V (2.5V with a little bit of a safety margin). When it finished charging, I hooked it up to a 680 ohm resistor and a green LED (Vf roughly 1.75 volts) in order to test the runtime. So far the LED has been lit for about 3 hours.
I am gonna use a whole lot of these in an array to build a emp ray for disabling robots in the future when the decide to take over!
Electronic Goldmine has some three kilofarad supercaps for a reasonable price. They have a demo where they hook some wire to one and it glows for quite some time.
Be sure to ask for the quantity discount!
I can't help but read all your posts in Farnsworth's voice...
Err, whaaa?
same here, haha
how about a 5v (or at least 3v3) version?
A typical 2.8 amp hour 1.5 Volt AA battery is the equivalent of 10,080 Farads. You'd only be able to power a low-current circuit for hours.
Try weeks. Check out this post on Hack A Day that talks about a low power microcontroller and its power supply: http://hackaday.com/2010/09/30/launchpad-takes-ultra-low-power-to-the-extreme/
Any example circuit for powering devices for a small period of time? Like for a pass off from one power source to another without disruption (a mini ups for solar powered routers)?
Part of the usage is charging the super capacitor in the first place and TI just introduced the BQ24640 for this purpose:
http://focus.ti.com/docs/prod/folders/print/bq24640.html
How long will it take to charge?
A reallll noob here wanting to do a project; Replace a 48 volt 750W battery with a supercap. to run an electric motor. The motor has an internal controller and is made by Bafang (Suzhou Bafang Motor Science Co., Ltd in Jiangsu, China).
So I guess my question would be, "What supercap would work to replace the battery?'
I have seen 2.5V 2600F supercaps on a video the other day, but those might be too expensive (even on eBay, a used set of 12 costs $420).
The possible runtime you'll get isn't really worth the money for most uses. Let's look at it in this way:
20x 2.5V 2600F = 50V 130F.
Energy stored in a capacitor is given by 0.5 x C x V^2. For this array, it would be 0.5 x 130 x 50^2, which equals 162,500 Joules. 1 Joule is 1 watt drawn for 1 second. So if your motor draws 750 watts, the theoretical runtime would be 216.67 seconds, or about 3 and a half minutes. However this is just an approximation, and the motor will most likely draw less power as the voltage drops, which would in theory give longer runtimes.
What are you planning on doing with the motor? Why do you have to replace the battery with supercaps, given that they have much lower energy density?
Am using a microcontroller( power supply is 2.7 v) interfaced with the sensor(5v power supply)and an antenna( 5v). I am in need of connecting super capacitor.. Which super capacitor will satisfy my need ???
I have a few questions about the datasheet:
What is the unit for the ESR? 40...miliohms?
And rated current is 4500mA, right?
And lifetime - is that how long it will hold a charge, or how long the capacitor will stay functional under normal usage?
Thanks!
Nichicon EverCap series seems to be super cheap for their capacity. Available from digikey/mouser. 100F for 15 bucks. Would be cool to get some power boards with voltage regulators or step-up converters preinstalled from sparkfun.
I just put this into my fan circuit. I am playing around with different things. I am waiting for them to charge. By the way is there any equation to solve how long it will take to charge these? I have two of them in a series with a 5.2Vin. I have been waiting about two minutes now, so this will probably take a while...
Edit:Just used an online time calculator...about 14 hours...
If you want to use these at 5V, try to avoid using them in series. Use this instead.
Could I safely power 4 of adafruit's 1 Watt 3v LED's for about 5 seconds at a time with two of these in series?
I would like to use this capacitor to power arduino. So if I connect three of them in series I should get 7,5V which is ideal for the arduino. However i'm wondering how to charge the capacitor safely. What kind of circuit I should make to charge it fast without causing any damage, is it enough to connect it directly to regulated direct current power source? Also if i would like to use it as a buffer of energy harvested from a solar panel that gives 5 volts how do I connect it so that when there is enough sun the capacitor would be charged, and when there is shortage of solar power it would power arduino. Any help will be appreciated.
These don't have the energy density of a battery, so you may be disappointed with the lifetime. There are capacitor discharge calculators out there; I put in a 10F cap, with 7.2V starting and 6.5V ending voltages (the 5V regulator needs 1.5V overhead to operate), and a 10mA load (10000000nA). The lifetime is only 11.4 minutes.
You can improve that though. One way is to supply AVR processor directly and not go through a voltage regulator (the AVR will run on unregulated voltage from 5V to 2V, but note that this will affect the I/O voltages as well). Another way is to have the AVR sleep when it's not busy; you can reduce the power draw to nanoamps this way. If you can get the average current draw down, you'll start seeing much longer lifetimes, especially if you're recharging the caps every day with a solar panel.
Thanks for the information, as this is just to test the possibilities of storing energy in capacitors, the really long lifetime is not an issue, thou I would like to try how efficient system I can make with those capacitors. I have one small prototype wich is just using buzzer, and a few leds and it is built on atmega 328p, with a small halogen lamp I was able to get enough "sun" energy to run it directly on the solar panel. Thou I still need to measure the power consumption. But it would be good to store extra energy from solar panel to capacitors to be able to use it when the sunlight is not sufficient. To keep the voltage stable I intend to use DC/DC step-up/down converter from poulu, as it starts working with just 2V. That should allow me to draw more power out of the battery of capacitors.
Wait, if most capacitors explode if you reverse the polarization, then what would the explowing be for a 10,000 farad capacitor? Or does the farad # have anything to do with the micro-explosion?
perfect gift :)
Could you power a motor or even robot with these, even for just a few minutes?
Motors might have too much draw...
Yes you can. These capacitors have a very low ESR and can provide large amounts of current.
anyone know if this is in the sparkfun eagle library? I had a board made with some caps, but the holes were too small for this cap. I ended up just shaving the cap's legs to fit in the holes, but I'd rather not have to do that in the future if possible.
I miss an important data in the datasheet.
What is the self discharge current at room temperature?
If this is low enough as to keep the charge for a few weeks this can be a good substitute for the TV/TDT/DVD remote controls, alarm clocks, low power toys, and hundreds of 2 AA or 2 AAA battery operated home appliances.
I'm tired of buying and trashing NiMH batteries. They have a high self discharge and their performance degrades in a few months.
Can you imagine having one of these in your remote and charging it by connecting it to a stabilized 2.5-2.7V, 500mA wall transformer for just one minute?
The self discharge at room temperature seems to be pretty bad from what I just measured. I had two in series with 2.08V on them, and they proceeded to lose about 1mV/s. This is when they weren't hooked to anything- I even removed the multimeter probes for a while to make sure those weren't draining current.
I'm not very happy with that since I have another 1F supercap that is pretty good at holding a charge, it's a PowerStor Aerogel PB Series, and only loses about 50mV per hour. I bought these Sparkfun ones to power a solar powered device over night so they're not going to work, and I need to buy some better ones off digikey. :-(
I did some calculations to compare these to the PowerStor one, and losing 1mV off a 1F capacitor is 500nJ of energy lost. But losing 1mV off a 5F capacitor is 2.5uJ, 5x more energy lost, which makes sense. Equation is E=(1/2)C(V^2)
EDIT: I tested this again later in the day and now they seem to be holding charge much better, even using the same multimeter and everything. Weird, maybe they just needed to be "broken in"? Or maybe the charge loss at higher voltages is much higher than at lower voltages?
Does anyone know who sells the larger caps in this series. I purchased some others recently which were rated to -40C. When I went to buy more the exact same ones now only go to -25C. I need the extra cold! thanks
What a crappy datasheet. I'm assuming the currents are in mAmps. Suntan? lol
Based on my experience, these caps tend to self-discharge over a period of time. I'm not entirely certain what the self-discharge rate is, though...
"The stored energy of a supercapacitor decreases from 100 to 50 percent in 30 to 40 days. A nickel-based battery self-discharges 10 to 15 percent per month. Li-ion discharges only five percent per month."
http://batteryuniversity.com/learn/article/whats_the_role_of_the_supercapacitor
Battery University is a pretty stellar resource in general.
Imagine if there was a 100V 1,000F capcitator.
Maxwell Tech makes a 2.7v, 150 continuous amp, 3000F cap.
They're quite a bit of fun I might add
those must be crazy expensive
Actually, a bunch of them showed up on the surplus market about a year ago, fairly cheaply. I bought half a dozen. Yeah, I have 18kF of capacitors.
digikey sells a 5000F capacitor
OH MY GOD.
Woooooooooooooow, that's a lot of farads!
This would be useful in say a Asus WL-HDD, for when the hard disk spins up, etc. It would let you run the system off a bank of 4 NiMHs.
See http://wiki.openwrt.org/OpenWrtDocs/Hardware/Asus/WL-HDD
Coil/Rail gun anyone?
Yeah, like Bret said, the discharge isn't anywhere fast enough to make a rail gun. They're made to discharge over a period of hours - a rail gun will drain it's caps in seconds or less. You could try, but explosions might occur...
Sadly, I don't think the discharge is fast enough on this to serve that purpose. But I could be way wrong, I'm not fully educated in electronics yet.
You are correct. Read this article.