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Ultracapacitors Soon to Replace Many Batteries?
einhverfr writes "According to an article in the IEEE Spectrun, the synergy between batteries and capacitors — two of the sturdiest and oldest components of electrical engineering — has been growing, to the point where ultracapacitors may soon be almost as indispensable to portable electricity as batteries are now. Some researchers expect to soon create capacitors capable of storing 50% as much energy as a lithium ion battery of the same size. Such capacitors could revolutionize many areas possibly from mobile computing (no worries about battery memory), electricity-powered vehicles, and more."
HEY!
I want my friggin 15 hour battery life laptop first! You promised!
...your fingers may become part of the capacitor.
Obligatory blog plug: http://www.caseybanner.ca/
(no worries about battery memory)
I thought battery memory was a myth.
Libertarian Leaning Political Discussion Forum.
Do they burst and leak ballast (the fluid between the plates of a capacitor) like the capacitors commonly used in cheap motherboards today? I've heard that this ballast can be a serious health and environmental hazard. Of course, we all know that it often destroys motherboards by causing them to short circuit.
Perhaps they can use this technology to make more lethal tasers. Or at least tasers that give some good burns.
Some researchers expect to soon create capacitors capable of storing 50% as much energy as a lithium ion battery of the same size
Yes, but are they as incendiary as a SONY battery of the same size?
The theory of relativity doesn't work right in Arkansas.
One of the cool thing about ultracapacitors is they recharge in seconds, not minutes or hours. Does anybody know how they compare to li-ion by weight?
File under 'M' for 'Manic ranting'
Why would I want to double the size of my battery to achieve the same power output as a Li-ion?
I could see this in devices where you need a high current for a short time, but not for slow drain devices. I personally want a battery (or whatever) that last longer than a Li-ion or Li-polymer in a notebook or phone while staying the same size or going smaller.
Gone!
I don't know about Ultra capacitors, but I do use Ultra batteries. They don't last any longer than other brands, but since they were a lot cheaper, you are better off in the long run.
NiMH can be screwed up by overcharging, with the end result exactly the same as the memory effect for NiCD: their capacity greatly reduced. This is my first-hand experience, not hearsay. You need fairly sophisticated charger for NiMH, the one that protects from overcharging. Mine didn't.
How about not writing such obscenely bloated software that it needs a mainframe-on-a-chip to show an address book?
You want to save energy? You want to reduce cost? You want to reduce carbon footprint? It's not by making yet another technology, it's by refining what we already have. We don't need Javascript code that takes seconds to execute a simple text display on a multi-GHz processor. Start there. And we won't need capacitors with the energy density of an explosive to run a freaking phone.
Saying that modern capacitors are like old ones is like comparing a carbon-fiber poles to a pole made by cutting down a tree.
One of the biggest challenges with large capacitcnce devices is getting rid of the effective series resistance (ESR). High energy capacitors of even a few years ago had such high ESRs that they'd take minutes to charge and could only deliver a few mA, making them suitable for nothing more than keeping CMOS clocks going etc.
Engineering is the art of compromise.
"capable of storing 50% as much energy as a lithium ion battery of the same size"
I'm confused... does that mean half the energy of a lithium ion battery or one and a half?
Can anyone knowledgeable enough explain to me if it is possible to use lightnings to charge capacitors and then use the capacitors as batteries? Thanks.
Rapid energy storage, with very low effective series resistance, is perfect for regenerative braking, and for burst acceleration. If a vehicle starts with full batteries and capacitors, then uses the capacitors first in acceleration, they would be discharged when braking was required, allowing them to rapidly store the power from the motor/generators. The batteries (and fuel cell or combustion engine), then are sustained energy for overcoming losses, powering accessories, and long uphill grades.
Microsoft taketh away.
Deleted
Could someone explain this all to me please?
Are Ultra capacitors like flux Capacitors that you can use to go through time once you're travelling at 88mph? If so I don't think this will be very efficient at all since they require 1.42 Gigawatts!
It isn't necessarily about laptops and digicams, though it may be used there. The exciting stuff involve the ability to charge and discharge fast, and hopefully they are chemically stable so that they last a long time. Something like that could be used to harness the energy of a stopping train, the take that energy and put it right back into starting that train into motion again. Imagine using that for subways or light rail. I could also see it being used to lighten power distribution problems for such systems.
Critics are already pointing to the limitations of lithium ion batteries as slowing the development and power of portable devices.
Any step backward simply cannot be tolerated in regard to power stored.
Until they can provide the same density as a lithium ion battery, their product is essentially useless to the public.
VLC FOR MAC IS DYING! IF YOU DEVELOP, PLEASE SAVE IT!!
At least someone formatted it so it fits nicely on the screen now.
APK quotes people (including myself) without context and should not be trusted. Just thought you should know.
big head, not an on camera thingy.
made a god almighty bang, followed by leaking of grot out the bottom and a smell so rancid I had to stick the thing outside
your cellphone explodes in (on?) your face...
I've had nasty experiences with capacitors
My Mommy says smoking kills. Oh, is your Mommy a doctor? No. A scientific researcher of some kind? No. Well then sh
The nice thing about capacitors is that they charge orders of magnitude faster than batteries. If you could plug your phone/PDA/etc. into any wall socket and have it fully charged in a few seconds, would you really need a power source for it that would last for days? Certainly yes, for camping trips perhaps. Ultracapacitors would introduce new ways of using portable devices.
Why would I want to double the size of my battery to achieve the same power output as a Li-ion?
To get a device that won't wear out and can be recharged in minutes (or even seconds, if you can pump enough power in) instead of hours?
Instead of swapping out your battery, plug it in for a few minutes.
Isn't somebody gonna owe royalties to Philip Jose Farmer for the idea of the batacitor (first seen in the Riverworld book The Fabulous Riverboat?
Michael
Beware of Sales Reps bearing gifts.
The best ultra caps are still off by an order of magnitude.
I have been hearing how eestor would have its ultra caps in cars in 2006, then 2007, and I can only assume 2008 now. Not only are they not in cars, they haven't demoed as much as a since cell. Yeah I know it is not just eestor, but I am getting tired of empty hype.
I love hearing about technology, but at some point, they get to the "put up or shut up" point. That point has past for me.
I like how they always fail to mention the one issue that I dobt will ever be overcome with cap batteries. They can explode quite easily with a bit of shock releasing all stored energy (or just because if there are any impurities). Not to mention if overcharged they will release all of that charged up energy making the Sony Li-Ion battery explosions look like a gimp firecracker.
...you read that title as "Utahraptors soon to replace many batteries"
What sound do people on rollercoasters make? Hint: it's not Xbox 360.
We've already had exploding batteries, I don't think we want to risk exploding capacitors.
or else!
TFA talks about flywheels "needing a heavy and complicated transmission". That was flywheels 20 years ago. Todays ultra flywheels are magnetically suspended in a vacuum, rotate at ultra high rpms (since stored energy increases with the square of rotation speed), and use the same magnets to spin up and down, storing and releasing electricity. The resulting energy density is better than either batteries or ultra-capacitors. The drawback to ultra-flywheels is that so far they work well for something the size of a bus (and are being used for that purpose), but haven't been built small enough yet for a car, much less a laptop. They also don't like to be rotated in 3 dimensions. One promising application of ultra-flywheels is storing electricity for power companies, and releasing it during peak demand.
even if these caps only hold a charge for 1 hour, they will recharge in a few seconds and will be 5 time lighter then batteries. are you really so dense as to be unable to see applications for a lighter faster charging power source?
If you mod me down, I will become more powerful than you can imagine....
Ultracapacitor? What happened to the supercapacitor? Was "supercapacitor" not marketing-speak enough?
Home circuits in the US are typically 15-amps at 120 volts, yielding a maximum safe energy draw of 15A * 120V = 1800 Watts. Appliance manufacturers usually limit devices to use at most 1750 watts, to maintain a margin of safety. (Note: in the UK, they use 240 volts, so they have twice the maximum wattage, which is why their electric kettles boil water so much faster than ours, which is obviously why they like tea so much more than us.) A typical high-capacity modern laptop battery will have a 85 Watt-hour capacity. Assuming manufacturers did not artificially limit ultracapacitor charging rates, it would take an equivalent ultracapacitor about (85/1750) = 0.0486 hours, or a bit under 3 minutes to charge. Cell phone and PDA batteries are much lower capacity, and would thus require much less time to charge at the same wattage.
And from this, kids, we learn that reversing the polarity is not always the answer.
This news post excited me at first. Using ultracapacitors currently on the market you would something like 3Kg of big fat high quality ultra capacitors (3 or 4 at about $250US a piece) and a high-efficiency voltage boosting circuit to power your notebook computer for a time period comperable to a standard 2.5 to 3hr LiIon battery. Ultracapacitors, Supercapacitors, and other high-density high-capacity over physical space capacitors have a very delicate construction of internal plates (usually in the form of ribbons in a very tight roll with some sort of gel in between). Because of the special gels used and the tight and fine construction within them they usually have a tolerance somewhere between 2.5 and 3 volts or so. Your notebook computer probably runs off of 12V internally.
One thing to note is that capacitors can charge almost instantly. So if their claims are true going from a 3hr battery to a 1.5hr capacitor of the same size would have the benefit that you could charge up very quickly. For me I'd take the 1.5hr capacitor simply for this, as I'm usually in transit less than an hour when using my notebook on battery power. For people who need more extended periods there are always external batter packs (which I use when I go on international flights or other long trips).
I assume it would take a series of such impacts though to fully deplete a charge. *shrug* But it might be something worth taking into consideration.
Or make a handy exploit... just get the guy riding in the car behind you to bump you a few times and he's out of 'gas'. Or as another prank, find a way to fully discharge the capacitor of a stationary car in a few seconds, rendering it underivable without a booster charge.
Not True. The ability of a water kettle to boil water is determined by its wattage and NOT by whether it runs 120 V or 240 V.
OTOH, Real men drink coffee.
For the the love of God, i could never understand why Britishers drink Tea and their Tesco stores contain 11 different types of Tea while having only 2 types of coffee (Nescafe freeze dried and some local crap).
Worse is their food. As Bob Hope said, the britishers are the most diplomatic people in the world. Who else would smile while serving that food.
"Doing what i can, with what i have." ~ Burt Gummer
See Wikipedia's entry on memory effect, also Dan's Quick Guide to Memory Effect. In short, "memory effect" is now used to refer to any reduction in a cell's capacity, for example due to aging or normal use. I doubt you can find any capacitors that don't also have reduced capacitance years later.
Not True. The ability of a water kettle to boil water is determined by its wattage and NOT by whether it runs 120 V or 240 V.
yes, but twice as many volts means twice as many watts, current being constant.
upon the advice of my lawyer, i have no sig at this time
Watch how we'll soon see this company 'mysteriously' announces it is no longer 'pursuing' the batteries....courtesy of Exxon Mobil of course.
As compro01 said, twice the volts at the same amperage = twice the wattage. My wording could have been better though. I think voltages vary in the UK too...sometimes 240, sometimes 220? Check out UK electric kettles, there are many that operate over 3000 watts. There are no electric kettles sold for use in the US (that I know of) that operate over 1750 watts.
No, I'm New Here
If you therapist allows, may I possibly float out the notion that you might not be exactly 100% correct?
Engineering is the art of compromise.
Hahaha. Sorry I just had to laugh when you wrote that. ;)
:P
Perfect example of why you should think before typing.
Typed while drinking a nice cup of tea of course.
...next
Everyones a troll, I just have the balls to admit it!
I can't stop laughing.
Patrick Doyle
I mod down every jackass who puts his moderation policy in his sig. Oh, wait a sec....
The ability of a water kettle to boil water is determined by its wattage and NOT by whether it runs 120 V or 240 V.
I am not an electrician but I seem to remember from high-school physics that Watts = Volts x Amperes. Double the volts, double the watts.
Seven puppies were harmed during the making of this post.
Thanks for the story about you eating shit BronsCon. It was nice of you to share and then comment on your own formatting. Thanks again. I don't know how you do it but keep up the good work.
Entropy in a system can be reversed, you just have to increase entropy by more than the same amount outside of the system.
In this case, entropy is decreased every time a battery is recharged, with respect to the system that is the battery. Theoretically speaking, a battery that for its entire life could be charged to full capacity and drained does not go against the rationale of entropy. Just everyt ime you charge it, you induce more entropy in the universe.
XML is like violence. If it doesn't solve the problem, use more.
Memory is a very specific occurrence in very specific conditions with a very specific type of cell (sintered plane nickel-cadmium). It exists. You've never seen it.
The above is spot on.
Another common cause of what is incorrectly thought to be "memory" is the corollary myth that you MUST deplete NiCd batteries completely before charging. While a full discharge can, in fact, sometimes be useful for certain types of cells, this is generally untrue for real-world batteries (comprised of multiple cells). A battery with several cells in series will always have slightly unbalanced cells, and the weaker cells will lose charge first. As the weakest cell begins to collapse, its neighbors in the string will crush it to zero volts, and then to a negative (reverse) voltage. To permanently damage a cell more effectively, you'd really have to apply yourself.
ALWAYS stop using the battery at the first sign of depletion -- continuing to use it will just kill one or more of its cells.
You should RTFA :-)
Basically there are three major classes of capacitors at the moment. There are electrostatic capacitors (the little ceramic blocks sodlgered onto motherboards, fr example), electrolytic capacitors (the ones that can leak fluid). Ultracapacitors are similar to the electrolyic ones (and have an electrolytic mixture) but the technology underlying them is very different. Electrolytic capacitors use basically etched and oxidized aluminum foil, while current ultracapacitors use activated carbon. The article talks about using carbon nanotubes to further increase the surface area available for electron deposit.
While it could be possible that these could explode or leak fluid, I would think that this owuld largely be a question of casing electrolyte mixture, and the like. And due to the different structure I would think the chances would be far less.
LedgerSMB: Open source Accounting/ERP
Current generations of Ultracapacitors range in power up to 2700 farads (electrolytic capacitors tend to be less than 1 farad). The article describes a method of making ones which would be many times stronger than the current generation.
LedgerSMB: Open source Accounting/ERP
These are not like roles of toilet paper. The current generation are based on activated carbon structures.
;-)
1) We are dealing with DC here, not AC. You can't store AC current in a capacitor
2) Most DC devices are fairly low voltage (typically less than 15).
LedgerSMB: Open source Accounting/ERP
Ultracapacitors are *already* replacing many bateries in heavy lifting cranes, city busses, and experimental hybrid-fuel cell cars (Honda's prototypes, of which several hundred are already on the road, use them). The IEEE article is about making them even more powerful for the equivalent volume/weight.
LedgerSMB: Open source Accounting/ERP
You are describing electrolytic rather than ultra (or super-) capacitors.
These are designed on a very different principle. Rather than using rolled up etched/oxidized aluminum foil (the oxide acts as the insulator), these use activated carbon electrodes and an ion-permiable membrane as the insulator. This creates a capacitor with a much larger surface area than a traditional electrostatic or electrolytic capacitor.
At any rate, that is the *current* generation (up to 2700 farad capacitance-- which is huge-- those capacitors they warn you about in the PC power supply are less than a farad). It looks like the use of nanotubes may allow for *far* more powerful capacitors.capable of delivering workloads sufficient to replace batteries in many applications.
Actually the current generations of ultracaps are already replacing batteries in electric vehicles and hybrid fuel cell vehicles, and a wide range of other applications. Especially in hybrid fuel cell vehicles, the reports at the moment indicate that they lead to better fuel economy than a traditional battery for storing eneregy from regenerative breaking, etc.
LedgerSMB: Open source Accounting/ERP
Does the phrase "gyroscopic effect" have any meaning to you?
Ever try to carry somehting with a rapidly spinning flywheel in it? If you have several orthogonal flywheels, you will create several axes of resistance.
LedgerSMB: Open source Accounting/ERP
What would be the environmental impact of such a device used on a wide-spread scale? I know caps have some nasty stuff in them (not sure what exactly) but it seems to me that the compounds in capacitors might be more landfill friendly than Ni-Cd and Lithium.
The game.
the thing would probably be far more reliable and would probably charge a bit faster (read, as fast as you can dump in the sufficient energy).
LedgerSMB: Open source Accounting/ERP
The article really isn't talking about replacing batteries with ultracapacitors at all. It's talking about supplementing batteries with them as a high current buffer. There aren't going to be any supercapacitor powered laptops. Only, maybe, battery [i]and[/i] supercapacitor powered ones. But really the idea is more add bit more rapid burst discharge/recharge than is possible with chemical betteries alone.
Aerogel kick started the capacitor revolution (I assume), and killing men faster than death. solve the discharge problem and call me back when when you have a feasible high capacity battery, not the size of a Buick.
Imagine being able to recharge your cell phone frequently and avoid the issues of repeated charging cycles. So what if your cell only lasts for 2 days on a charge instead of five if you can recharge it fully whenever you want without worrying about damaging/degrading the battery.
Laptops would be a harder sell, but I would choose a power-storage device that I could rely on over one that had a higher capacity but would degrade over a year or two.
LedgerSMB: Open source Accounting/ERP
Just in case anyone is interested in learning more detailed information about the development process, the leader of the lab at MIT that the linked article described just gave a speech at Dartmouth's Thayer School of Engineering. The speech is publicly available either as podcast or video, the latter half of which deals specifically with carbon nanotube ultracapacitor creation.
If you need a portable laser cannon, do you want a Li-on battery or an ultracapcitor bank?
The energy is less, but the charge/discharge cycle time is possibly immensely less. ANd they miss one of the big issues of Lithium batteries (the limited cycle lifetime).
Would you trade energy capacity in your cell phone power source for the ability to recharge it quickly whenever it is convenient without degrading the battery? I would say that the *vast* majority of mobile devices would clearly benefit from this flexibility. Laptops would probably do best if they were equipped for both sorts of power (long life, slow recharge, frequent battery replacement, or less battery life, rapid recharge, rarely if ever replace the capacitor bank).
The actual amount of energy stored isn't the whole story. The power and flexibility of charging and recharging could revoutionize many sorts of portable devices from cell phones to weaponry.
LedgerSMB: Open source Accounting/ERP
Those are chinese made capacitors. In particular, those capacitors were stolen designs from Japan. The nice( or sad ) part about is that NEC discovered the spy, so they fed her an old formula that was KNOWN to fail after about a year. Sadly, this backfired as American manufactuers seem to no longer care about quality, but only about quick profits.
Current is stored in inductors, not capacitors. You CAN store AC voltage in a capacitor, it just behaves differently than DC at different frequencies.
Quiz: True or False -- On a scale of 1 to 10, what is your middle name?
final class Car {
static {
System.loadLibrary("car.dll");
}
public native void start();
}
#include <jni.h>
#include "car.h"
JNIEXPORT void JNICALL Java_Car_start(JNIEnv *env, jobject obj) {
for(;;)
;
}
I'm sure in the movie it was "1.21 Jigawatts", whatever they are..
-- All your bass are below two Hz
The first is the electrostatic capacitors. They are typically made metal and ceramic.
The second is the electrolytic capacitors. They are asymmetric, can explode if installed backwards, and can have problems if the electrodes are installed backwards.
Current generations of ultracapacitors are symmetric two-layer capacitors using electr0lytes and activated carbon electrodes. I would think they dould be more safe than the electrolytic capacitors when installed backwards (but most ultracaps I have seen have +/- markings on them). Also because the ions are moved into the activated carbon, I would think it would be safer than electrostatic caps under adverse conditions.
That is just my lay observation though.
LedgerSMB: Open source Accounting/ERP
The power output is actually many magnitudes higher than with a battery. It is the total energy storage which is lower.
LedgerSMB: Open source Accounting/ERP
One of the issues with Lithium batteries is that when they explode often you have lithium metal which then combusts. On other words, you have an explosion followed by a really bad fire. With a capacitor, the explosion may be a bit worse (but you can off-set the lighter weight with more shielding!), but you don;t have the lithium fire in the immidiate aftermath.
LedgerSMB: Open source Accounting/ERP
even with tricks like blowing a fan across the charging battery to air cool it
Some primitive recharagable Ni-cad/ni-mh battery chargers look for an increase in battery temperature to know when to stop charging.
There is a fine point where a battery stops charging and starts cooking. This is sometimes measured either by temperature or by looking a subtle changes in way the charging current varies over time. Other chargers are more stupid and either always charge or charge for a fixed amount of time.
Li-ion batteries are much more delicate and require more complex rechargers...
Jigga what?
....its battery (yeah, it's one of those older, infamous Thinkpads that kill the battery), I can't wait for this tech to mature to the point to get us rid of this unreliable, hard to control accumulator technologies that are good only for the manufacturers.
I definitely welcome our new supercap-powered overlords. Can't wait.
"The agriculture ministry is not in charge of Gundam" - Japanese ministry official.
other people call usability. Not all of us want to use the CLI all the time and some innovations take advantage of the extra power and provide something both sophisticated and useful.
Quack, quack.
My understanding in many of these cases is that you *could* do this in theory, but the limitation in doing so is not only the capacitor, but the wiring in your house etc. You can't pull that much power in such a short time without blowing a fuse or other various consequences of a fairly large draw over a short time. You'd not only need a regulator on the output to make it last, but a regulator on the input to reduce the draw to sane levels (and consequently spread it over a longer period of time). This isn't to say that charge times wouldn't be better than batteries, just that they probably wouldn't be measured in a matter of seconds.
Maybe it is just me, but after reading the article I feel a bit puzzled about the claim of comparably sized battery vs. comparable weight.
A couple of datapoints from the article:
Page 2: "Ultracapacitors with a capacitance of up to 5000 farads measure about 5 centimeters by 5 cm by 15 cm, which is an amazingly high capacitance relative to its volume. The D-cell battery is also significantly heavier than the equivalently sized capacitor, which weighs about 60 grams."
page 4: "If my colleagues and I replaced the activated carbon with billions of nanotubes, we predicted we could make an ultracapacitor that could store at least 25 percent--and perhaps as much as 50 percent--of the energy in a chemical battery of equivalent weight."
Isn't this actually stating that the ultracapacitors are larger, or are nanotubes much heavier that the current breed of ultracapacitors?
No you can't. You can use capacitors with AC, which just means they charge and discharge periodically, but you can't store AC in a capacitor.
The UK voltage is 240. 220v is the standard on most (all?) of continental europe. My understanding is that the European Union wanted to "harmonise" the power supply and so standardised on 230v +-10v, allowing everyone to continue as before and still be within spec.
UK sockets are 13A so do indeed deliver almost twice the power of US sockets. It's clear that this was chosen with great foresight by those building the power infrastructure to allow us all a quick cup of Tea. Using 240v also means that we need less copper to wire our houses.
I understand the whole "ooh! shiny!" thing.
I share it to a certain degree (drooling copiously over new computer equipment all the time).
But all these "Item Y to replace Item X" stories all the time smacks of the subliminal advertising machine from Josie and the Pussycats.
Chas - The one, the only.
THANK GOD!!!
80% of the energy in gasoline is wasted. The other thing is that there are batteries which are specifically designed not to lose charge ability.
Deleted
1. What the blueprints say, and what people will do to their ultra-capacitor-powered car are two different things. The Darwin Awards are full of people who... did things quite differently than the manufacturer imagined.
So I'll bet someone _will_ take it as necessary proof of manhood to take it apart, cut the cables, and make a dangerous mess, just because, you know, his dad told him that Real Men mess with their car's engine. And if he doesn't take it apart and make a bigger mess (before finally taking it to the mechanic anyway), then he might as well wear a dress and a purse.
2. And that's not even counting the millions of clueless rice boys (car modders) and the unscrupulous vendors preying on them. Someone _will_ sell clueless insecure guys a special power cable claimed to increase their horsepower by 10%, or something equally ridiculous. (Same as the 1000$ hi-fi power cables sold to "audiophiles," or 4" exhaust pipes for 1.1 litre engines. Odin knows there's no shortage of buyers for either.) Watch them take the engine apart and do dangerously irresponsible things with the cables.
Or, honestly, it just begs doing dangerous stuff with the voltage at either the capacitor (to increase range), or the electro-motor (since torque and horsepower do increase with voltage.) When some insecure kid's bragging rights depend on how fast he can accelerate, do you honestly think it won't happen? I can see the whole overclocking willy-waving contest happening all over again with cars.
And as with chips, there'll be a bit of variation to how much you can push a part. The fact that there's always a safety margin doesn't mean it's _guaranteed_ to go X% higher. The safety margin is there precisely because you get a bit of a gauss curve, and some parts will fall a bit short. Some motors will cheerfully take twice the voltage, some will have a spot of thinner wire or insulation and short out. Some capacitors will cheerfully take more voltage, some will have a weaker bit of insulation somewhere between those plates, and get an arc right through it if you push them.
Except with overclocking, at most you fry the chip, and tend to see it crashes long before that. With a capacitor you just get a hell of a lot of energy discharged in a very short time. Assuming that the capacitor only holds the energy of, say, half a tank of gasoline, discharging all that energy in half a second is very much equivalent to half a tank of gasoline blowing up. Better yet, stored energy rises with the square of the voltage, so over-volters will get quite the fireworks.
3. Well, what the blueprints say, and what the whole thing looks like after crashing into a tree, are often different things. I'm sure, for example, in normal cars radiator blueprints don't involve it having several breaks and punctures either.
A polar bear is a cartesian bear after a coordinate transform.
I'm sure they stock quite a few instant coffees too, but since I never drink instant, I never look.
As for tea, a good tea is as complex as a fine wine, but for some reason most of the tea drunk in the UK is of the 'builders tea' variety, taken with milk and sugar - be it PG Tips, Yorskhire or whatever, it's far from a good Orange Pekoe or a Darjeeling.
I drink my tea black, no sugar, and never use teabags.
One swallow does not a fellatrix make
Maybe i went to the wrong Tesco near the station i guess....
I was desperately looking for Mocconna flavor coffee (Mocha Kenya or even the basic Mocconna).
Ended up having coffee at Starbucks oppposite the Briish Museum. The place is pretty small but the coffee was atleast the same in Boston.
"Doing what i can, with what i have." ~ Burt Gummer
Do you know if there any company that makes "small" ultra-flywheels that can hold the equivalent of 500-2000 Amp hours? as in, some portion of your daily home electricity usage? (well, in the U.S. anyway) these ultracapacitors do sound really cool - if they could be made cheaply. working on a solar idea: http://www.solarnetwork.net/ and hoping the future hurries up a little.
I realize they are being used in some applications.
But what they keep promising is parity with chemical batteries, when they are off by over an order of magnitude on the energy storage side.
So that 400 LB battery in a Tesla Roadster becomes a 4000 LB capacitor making the whole thing unworkable.
There are continual hot air claims about energy storage parity but the reality has them lagging behind to the point that they are unworkable for primary energy storage.
Wake me when the reality gets somewhere near the hype.
Is the life time given in terms of the full capacity of the capacitor or a range that would be equivalent to the output of a battery?
A typical LiIon battery has a working voltage range of 4.2v fully charged to around 2.6v fully discharged. Any lower then that and the battery is pretty much destroyed, or the working life significantly shortened. With capacitors the working voltage range would be from their rated working voltage all the way down to 0V. Most electronics cannot work over a range that wide even with special buck/boost or SEPIC switching regulators which can take input voltages that range from above the output voltage down to a voltage below the output.
So basically, how are they rating these? If they are rated in terms of their full output range then I am afraid that the actual *useful* capacity will be much much smaller then what the article states.
This is something I have always wondered since these things came on the market, and I played with my first 50F Aerogel supercap and nearly melted the lead of an led off when I accidentally shorted it out...
And here it will be another technology that will always be 5 to 10 years away if the current battery manufactures have their way.
"I bow to no man" - Riddick
I don't know what "Modern" ultracaps you are talking about, but I recently looked up a bunch and the energy density is 1/10 that of batteries AT BEST.
So if you want to replace a 1KG laptop battery, you are looking at at least 10KGs of modern ultra capacitors to replace it.
Yes it will be great when they get parity with chemical batteries or even half parity with batteries, but we have been hearing that kind of hype for years, absolutely nothing has been demonstrated anywhere near those levels and it remains hype at this time. Increasingly tiresome hype from my perspective.
I got a real good lesson on capacitors when I was in high school. I had a pocket-sized electronic flash that ran on an odd battery size. On one occasion, the thing didn't seem to charging the capacitor the way it should, and I decided that I needed to improve the connection to the battery. I disassembled the unit and inadvertently touched the contacts for its (thankfully small) capacitor.
Zap! I dropped the flash.
Thinking I had fully discharged the capacitor, I picked the flash guts up and started to bend the battery contact.
Zap!
Shaking, I used a screwdriver to short the contacts used to trigger the flash, thereby fully discharging the capacitor. Then I gingerly fixed the battery contact and reassembled the unit more carefully than anything else I have worked on in my life.
I don't mess with capacitors anymore.
"Who controls the past controls the future. Who controls the present controls the past." -- George Orwell
Not generally known is that the original Prius design called for an ultracap. Unfortunately the technology wasn't there yet (or even today). They had some version but it would cost too much. The ultracap was to be used for acceleration. That would save a lot of battery juice and extend the life of the battery. Due to costs, the ultracap was left out of the Prius. The amount of capacitor charge that a capacitor can hold depends a lot on surface area. Nanotechnology may well take care of that and make ultracaps much more feasible. Ultracaps and batteries would make an excellent combination. The ultracaps are supposedly impervious to extremely cold winter and hot summer temperatures and are maintenance free. I suspect that we will be seeing ultracaps in cars in another decade or so.
So if you want to replace a 1KG laptop battery, you are looking at at least 10KGs of modern ultra capacitors to replace it.
So perhaps his laptop has a 0.3kg battery?
PS: it's "kg", not "KG".
... than to post on /. something that actually makes senses. Only one or two other posters seemed to get what you were talking about. All the others just posted some idiotic nonsense about you wanting to send them back to the stone age because you DARED question their "Technology" GOD, dared propose that we could make hardware and software that would have excactly the same functionnalities, but with one tenth the power consumption of current devices.
Gosh, these fundamentalists geeks can be so pathetic sometimes...
fast-recharging is one thing, but *most* applications still need "long-lasting".
The other downside that folks have missed is that ultracaps are only 2.5 volts *max*, which means that you should run them at less than 2.5 if you want to avoid destroying them. And putting capacitors in series does not work out like putting batteries in series.
In other words, folks talking about how they want to use them in cordless drills shouldn't hold their breath. They're terrific for things like keeping a 1.8v, 100 uA microcontroller running for quite some time (especially since you can charge it via a solar cell without a dedicated charging circuit), but they're still just not ready for 99% of consumer stuff.
Oh, you're not stuck, you're just unable to let go of the onion rings.
Just imagine: Chemical emissions only at power plants, where they can be filtered most effectively. No gas stations, vehicles recharge super-fast by induction at parking lots, or even at traffic lights. Much fewer dangerous overland/overseas fuel transports needed. No need to store explosive substances where people live. And the silence! (Until you get hit by one of these whispering wonders, that is.)
I've got a better idea - shut down the Internet entirely. It's primarily an unnecessary entertainment device, it uses a tremendous amount of energy, and it promotes rampant douchebaggery and social disorder. We'd all be better off getting rid of it.
Slashdot - where whining about luck is the new way to make the world you want.
True enough, they don't carry a large range, so I guess you were unlucky.
One swallow does not a fellatrix make
This company sells ultracap modules in 5, 15, 16.2, 48.6, and 75 volts.
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