Air Temp Nitinol

[gadgetmall]

As they are discharged, does the voltage start dropping immediately, or like
a battery, do you get most of the power at the rated voltage, which drops
as the cap empties?

hello Paul-R . the Volts will drop but the current is still there . One of those Big 2700 farads last months of experimenting . you can see in that demo of that particular Ucap that even after shorting and burning it has more power left . Enough to start fires and melt wires even at .5 volts they make wires glow .I think i remember it was calculated that a 650 farad ultracap charged can release 3500 amps all at once but they won't go dead that fast . In a dead short it take a while before all that energy goes away . The amazing thing about them is i can charge one up in less than 20 seconds to full capacity and it will run several circuits for months and months ..That deal on ebay is a steal for less than 25 dollars  . These things 4 years ago were 400 dollars each . and the 650 was close to 190.00 I used to sell them and get them from the manufacture in cases  and sell them at a discount .but soon found out i can get them off ebay for a fraction of the cost . No one can compete with Ebay's prices .Very good value and Quality . However i have bought leaky ones from a seller . They have an electrolyte in them ,just a few drops and i have seen some not welded properly and that poison stuff is gone and the bcap is like a normal capacitor  when i tried and charge them. just a few .

[Lakes]

Good for a bit of spot welding then...

[gadgetmall]

Good for a bit of spot welding then...

true . carbon rods really light up and get HOT.

[DreamThinkBuild]

Hi Paul-R,

Caps are linear devices, they discharge/charge linearly based on current draw/amps. They lack the Ah of a battery but make up for it in sheer power output(high current)/quick charging time.

Hi Gadget,

Solar+Ultracaps make the perfect couple. I have a solar spot light I got from Lowes and replaced the weak batteries that would be dim by morning with two 3000F ultracaps. It runs all night brightly for a hall light.

Have you tried ambient charging with ultracaps? Short one out through a 10ohm power resistor to about 10mv, take off the load and leave it. Check the voltage in about 2 hours the voltage should start to climb, I usually get about 200mv+ by the end of the day.

Hi Lakes,

Arc welding is easy with them.

[gadgetmall]

Inside the Bcap :

An ultracapacitor stores energy electrostatically by polarizing an electrolytic solution. Though it is an electrochemical device there are no chemical reactions involved in its energy storage mechanism. This mechanism is highly reversible, allowing the ultracapacitor to be charged and discharged hundreds of thousands to even millions of times.
An ultracapacitor can be viewed as two non-reactive porous plates suspended within an electrolyte with an applied voltage across the plates. The applied potential on the positive plate attracts the negative ions in the electrolyte, while the potential on the negative plate attracts the positive ions. This effectively creates two layers of capacitive storage, one where the charges are separated at the positive plate, and another at the negative plate.
Conventional electrolytic capacitors storage area is derived from thin plates of flat, conductive material. High capacitance is achieved by winding great lengths of material. Further increases are possible through texturing on its surface, increasing its surface area. A conventional capacitor separates its charged plates with a dielectric material: plastic, paper or ceramic films. The thinner the dielectric the more area can be created within a specified volume. The limitations of the thickness of the dielectric define the surface area achievable.
An ultracapacitor derives its area from a porous carbon-based electrode material. The porous structure of this material allows its surface area to approach 2000 square meters per gram, much greater than can be accomplished using flat or textured films and plates. An ultracapacitors charge separation distance is determined by the size of the ions in the electrolyte, which are attracted to the charged electrode. This charge separation (less than 10 angstroms) is much smaller than can be accomplished using conventional dielectric materials.
The combination of enormous surface area and extremely small charge separation gives the ultracapacitor its outstanding capacitance relative to conventional capacitors.