Capacitor and capacitance

  • Thread starter Bassalisk
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948
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What is the highest capacitance ever made/achieved?

I am asking this because, when I am solving some time domain circuits, the values are given like 3 F etc. And I know that is absurd, and I really hate it because, if I didn't take electronics at home, I wouldn't have the feeling for high/low capacitance.

But anyway, what is the highest capacitance ever recorded?
 
137
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Achieved by the Nature, probably, recorded by the Brazilians, most probably - in the Amazonia regions.
 
948
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Achieved by the Nature, probably, recorded by the Brazilians, most probably - in the Amazonia regions.
That capacitance is?
 
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If you google "5000 Farad capacitor" you'll see that there are several companies selling capacitors of that capacitance. So 3 Farads is not a ridiculous number.
 
948
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If you google "5000 Farad capacitor" you'll see that there are several companies selling capacitors of that capacitance. So 3 Farads is not a ridiculous number.
omg. You can store a power plant in it?!?!? :D
 
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omg. You can store a power plant in it?!?!? :D
Yeeeaaaah, I guess 5000 F is pretty ridiculously large. Considering that if you hooked it up to a single volt of power, you'd get 5000 C ... Which, discharging in 1 second, would give you 5000 W. Nbd.
 
948
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Yeeeaaaah, I guess 5000 F is pretty ridiculously large. Considering that if you hooked it up to a single volt of power, you'd get 5000 C ... Which, discharging in 1 second, would give you 5000 W. Nbd.
5kW ?!?!? Thats like freakin' 5 washing mashines :rofl:
 
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http://powerelectronics.com/passive_components_packaging_interconnects/capacitors/1000-3000-5000-farad-ultracapacitors-031810/" [Broken] of the place that sells 5000 F capacitors. It says they're for "A wide range of high-power applications, such as transportation, electric utility, material handling, industrial bridge power and renewable energy generation."

... so they could very well be powering 100 washing machines with that capacitor. :)
Although, keep in mind that it's only 5 kW if it discharges in 1 second. That's apparently not the intent, since the site also says they're for "long-operating-life energy storage."
 
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5,419
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5kW ?!?!? Thats like freakin' 5 washing mashines
If you are taking in washing now I have some available!

:rofl:

Meanwhile ask yourself what is the capacitance of a 200 amp hour 24 volt lorry battery?
 
948
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If you are taking in washing now I have some available!

:rofl:

Meanwhile ask yourself what is the capacitance of a 200 amp hour 24 volt lorry battery?
Well, using my prestigious knowledge of physics, and quantum mechanics, taking in the Schroedinger's wave equation, adding in the spin of the electrons, shape of the battery is approximately cylindric...

My final answer is I am clueless :rofl:
 
948
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But still what is the capacitance of that lorry battery? Must be huge.
 
309
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Sparkfun sells a 2.5V 10F "super capacitor", so it's possible even with small electronics components.

http://www.sparkfun.com/products/746

You not likely to ever use something like that except in specific applications though, I imagine.
 
948
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Gotta admit, I learned a lot of stuff through these forums... A LOT
 
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My final answer is I am clueless
Here's a clue

200 amps for 1 hour = 200 * 3600 amp-seconds = 200 * 3600 coulombs

Capacitance = Q/V
 
948
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Here's a clue

200 amps for 1 hour = 200 * 3600 amp-seconds = 200 * 3600 coulombs

Capacitance = Q/V
30 000 farads ?!?!?

Why aren't we taught this example? :D

But there has to be a catch. These coulombs will released slowly right? Opposing to that 5000 in one sec?
 
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Batteries don't have capacitance.

They have capacity, but not capacitance.
 
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BTW, the capacitance of thunder clouds is very small - contrary to what I have thought.
 
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Batteries don't have capacitance.

They have capacity, but not capacitance.
in curcuiit theory an ideal battery is equally modeled as a capacitor of infinite capacitance.
 
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in curcuiit theory an ideal battery is equally modeled as a capacitor of infinite capacitance.
Studiot's calculation is still meaningless.

Batteries aren't capacitors.
 
948
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Studiot's calculation is still meaningless.

Batteries aren't capacitors.
Yes but they do store charge? Or produce it... through chemical reactions, that has a equivalent capacity

capacity is by definition: Charge/potential.
 

sophiecentaur

Science Advisor
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If you measure the rate that a Capacitor discharges through a Resistor (for instance, how long it takes for the volts to drop by 10%), you can find its Capacity. You can do precisely the same thing with a charged battery, which will make it appear as if it has a Capacitance. The difference is that one discharge will be exponential and the other won't. (The battery will be more like an approximate Voltage source.) The effective Capacitance' of the average battery that you can buy over the counter is a lot higher than the Capacitance of even a 'massive' Capacitor.

The very low internal resistance of a Capacitor gives it a number of advantages over a battery though (the fast achievable discharge time was mentioned above, for instance)
 
948
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If you measure the rate that a Capacitor discharges through a Resistor (for instance, how long it takes for the volts to drop by 10%), you can find its Capacity. You can do precisely the same thing with a charged battery, which will make it appear as if it has a Capacitance. The difference is that one discharge will be exponential and the other won't. (The battery will be more like an approximate Voltage source.) The effective Capacitance' of the average battery that you can buy over the counter is a lot higher than the Capacitance of even a 'massive' Capacitor.

The very low internal resistance of a Capacitor gives it a number of advantages over a battery though (the fast achievable discharge time was mentioned above, for instance)
Yes I agree, makes sense.
 
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Batteries are not capacitors!

One stores energy in the electric field between two isolated plates. The other stores energy in the chemical bonds of an acid touching two different kinds of conductive metal.

There are not even remotely the same thing. Please stop confusing the issue by making misleading comparisons.

Despite the similarity in the terms, capacitance of a capacitor (measured in farads) is very different from capacity of a battery (measured in amp-hours or joules). Comparing the two is like comparing pounds to pascals because they both start with "P".

The theory and math behind how the two work is totally different.
 
948
2
Batteries are not capacitors!

One stores energy in the electric field between two isolated plates. The other stores energy in the chemical bonds of an acid touching two different kinds of conductive metal.

There are not even remotely the same thing. Please stop confusing the issue by making misleading comparisons.

Despite the similarity in the terms, capacitance of a capacitor (measured in farads) is very different from capacity of a battery (measured in amp-hours or joules). Comparing the two is like comparing pounds to pascals because they both start with "P".
We are talking about capacity, not capacitors :D. Capacity is by definition Q/V. A single point charge has capacity in some point around it.
 

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