650 Farad Ultracapacitor shorted across piece of wire

[CalicoatMaker]

@Arcagelinos1 They dont really act the same as "traditional" capacitors.Cheap way to get them is to watch for those "shake light" flashlights to go on clearance. I got a bunch of .22uF 5.7v supercaps from some 87-cent flashlights (and a nifty yet fragile as hell crafted rare-earth magnet). I tore apart a $1 solar yard "sticklight" and put these caps inside it along with the NiCad AA battery it came with, then a 4100k Cree LED. Bright as HELL, lasts 36 hours. I love supercaps :)

Cheap way t

[spuzzdawg]

@CalicoatMaker On what planet is 0.22uF capacitor considered a supercap?

[WingedMark]

Yes I realize that the power supply was still connected, but given that is has a one amp maximum current output, it has a negligible effect on the outcome. Why you think it's a big deal is beyond me, this was clearly not any kind of scientific test with results recorded.

[supertruckertom]

Its extremely low ESR allows it to dump the energy without it turning into internal heat on the way out.

[WingedMark]

I am not convinced... The capacitor doesn't heat up at all when doing this.

[ReiMomo]

The life of super capacitors is shortened too quick if you short them like that.

[WingedMark]

Edit to my last post, you don't need a 'high' voltage, just a voltage that is higher than your desired charge so current will flow.

[WingedMark]

72fr250 -- I use an Anatek variable power supply, and if I'm feeling anxious I have a 'wall wart' transformer that I connect in parallel to speed things up.

You will require a high voltage on the charging side, but be careful to cut the charging supply at 2.7 volts or less or you will damage the unit. I fried the IC that came with my cap the day I got it, and I just watch the voltage across the cap with a multimeter now.. Haven't forgotten about it yet, but it's not the safest method.

[WingedMark]

Pirate -- It was about $40 canadian off ebay with a few little solar panels and LED's.

EgadsNo -- Nope, copper wire

jwhite -- I wouldn't recommend to you trying this at home. Ultra capacitors are good to accept or discharge large amounts of current, which is why they are a shoe in for regenerative braking solutions, look it up.

userABC -- The voltage so low that no, it will slowly heat. Power is a function of both voltage and current, and the capacitor maximum is 2.7 volts.

[72fr250]

How do you charge it up? I have the 3000 farad version hooked up to a 2.5 volt 3.5 Amp solar panel, and i can only get it up to around 2 volts...

[xxGLhrMxx]

@72fr250 Dude, i dunno the size of your panel, but in general, solar power would take months to charge a 3000 farad capacitor...

Use your home power instead

[72fr250]

@xxGLhrMxx I have a 16.2 V 2000 Farad bank now. I need to do a charge time test, but in general I never have a reason to fully discharge the bank, so solar is fine for maintaining the voltage. I like solar power over home power just because wall warts and chargers will fry without a large power resistor when you charge these caps.

[EgadsNo]

was that nichrome wire?

[zker666]

that is 2304 joules of energy you have right there, usually at that amount of joules, it is high voltage, and the wire would simply evaporate. But at this low voltage, the wire is just used to dump the energy out

[cappydawg]

@zker666 I got 2886 Joules

E = QVsq

E = 650 x 2.1sq

E = 2886.5 joules

[jwhiteheadcc]

I highly doubt that thin wire could get anywhere near 100 amps, but that's still impressive. Hehe.

Isn't it really dangerous to short a capacitor of that Farad rating? I'm thinking of the motherboard capacitors that went *POP* on so many people's computers in the last few years. Discharge rate was heating them up and they had fake electrolytes which allowed overpressure.

[Pirate88179]

Nice job! I used this same boostcap with a joule thief circuit to run a 48" florescent tube from my earth battery. These are great devices. Join us over at overunitydotcom in the second stage joule thief topic where one of our members is running a heater at overunity from an aa battery.

Bill

[likmahchoda]

How much did this cap cost you?

[WingedMark]

The datasheet I found from Maxwell stated the short circuit current as 3500A.. Impressive either way.

[Auhydride]

Datasheets say maxwell 650 farad ultracaps can discharge at 2300 Amps, the second thing i did was of course try it on a wire :D

[taunto]

Man, that unit has some serious potential! That wire was glowing madd red!