DanielJ
Newly Enlightened
Are these compatible for decorative lights and floral arrangements? Compared to batteries, wouldn't it 100X the battery life?
Electric double-layer capacitor with LEDS
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AnAppleSnail
Flashlight Enthusiast
I saw a 1F/5v ultracapacitor for use as a USB-charged microlight. Look up how to convert F and V into mA over time, and the energy density is shockingly low. Capacitors in general shine over batteries in POWER density, cranking out amps in under a second. That's good for:
Camera flashes
Strobe lights
Surge filtering (AC rectification & smoothing, etc)
Ultracaps trade some of that power density for more energy density - a sort of hybrid with less energy capacity than a battery and more ability to send current in a moment.
For floral arrangements, I can suggest clever ways to hide the batteries. But primaries are likely to be your best option.
MikeAusC
Enlightened
I connected at 15 volt 1 Farad capacitor as used for car sound systems to 50 watt Halogen bulb and 12 volts.
When I disconnected the 12 volts, the light stayed bright for 3 seconds then dimmed very quickly.
12 amp-SECONDS of storage isn't that much use as a battery.
A 12 amp-HOUR battery is about the same size and cheaper.
When I disconnected the 12 volts, the light stayed bright for 3 seconds then dimmed very quickly.
12 amp-SECONDS of storage isn't that much use as a battery.
A 12 amp-HOUR battery is about the same size and cheaper.
ProstheticHead
Newly Enlightened
- Joined
- Oct 3, 2011
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I'm in the process of building an EDLC based flashlight. I've purchased a cheapish XP-G R5 pocket torch that will accept anywhere from 3 down to 0.8 volts (important since capacitors voltage decreases across their entire range as they drain, unlike electrochemical cells which tend to have relatively flat discharge profiles) from one AA (or 14500) sized cell. I'm going to take the head and tale cap (all the LED, boost and regulator electronics, switch, reflector) from this torch. The EDLC I've chosen is a 3000 farad, 2.7V 'BoostCap' - this is about the size of a coke can and stores slightly more energy than a good NiMH AA cell. This SHOULD give me a run time of ~1 hour at ~160LM or 2.5 at 70LM and much longer in the ultra-low mode. The charger is actually a high power LED driver board which has ajustable voltage (which I will set to 2.68V) and output current limiter (I will set this to 5A). This is needed since 1) The EDLC will be damaged if exposed to too high voltage and I don't want to have to bee fussy about input voltages for charging. 2) The EDLC has extremely low internal resistance, without a current limiter of some sort it essentially acts as a short and would damage my internal wiring and any charger used. I can then charge it from any DC power source in the range 4 - 35V (any car, usb port, my 12v hand generator, etc).
The reason I'm building this:
1) To play with EDLC technology - the main reason i just interest and because I can
2) Near infinite rechargability.
3) Extreme cold resistance.
4) Rapid charge times - limited by power supply and my current limiter settings. With a carefully designed system could charge to 90% in a few seconds.
Drawbacks:
1) Size. The energy density of EDLCs is still a lot lower than electrochemical cells. I will end up with single AA performance from a flash light that won't fit in even my biggest pockets.
2) Cost. The EDLC, charge circuitry add a lot of cost. Approx cost EDLC £50 vs good NiMH £1.5 each.
Another fun application and something I might try in the future is very short run time, ultra high output. EDLCs can generally sustain extraordinarily high current drain. The 3KF 2.7v cap I'm using can output over 3KW - just try that safely with lithium cells. Couple some EDLCs with a ultra high output lamp and you could get many thousands of lumens in a surprisingly small unit - as long as you don't mind it only running for a few seconds.
This might not help answer your question, but thought you might be interested in an example application of EDLCs and LED technology. My guess is your best bet for decorative stuff is electrochemical cells. To get equivalent run time an EDLC needs to be many times bigger. The only real advantage for your needs would be if you plan to charge cycle it VERY often and don't want to ever have to replace the rechargeable battery.
The reason I'm building this:
1) To play with EDLC technology - the main reason i just interest and because I can
2) Near infinite rechargability.
3) Extreme cold resistance.
4) Rapid charge times - limited by power supply and my current limiter settings. With a carefully designed system could charge to 90% in a few seconds.
Drawbacks:
1) Size. The energy density of EDLCs is still a lot lower than electrochemical cells. I will end up with single AA performance from a flash light that won't fit in even my biggest pockets.
2) Cost. The EDLC, charge circuitry add a lot of cost. Approx cost EDLC £50 vs good NiMH £1.5 each.
Another fun application and something I might try in the future is very short run time, ultra high output. EDLCs can generally sustain extraordinarily high current drain. The 3KF 2.7v cap I'm using can output over 3KW - just try that safely with lithium cells. Couple some EDLCs with a ultra high output lamp and you could get many thousands of lumens in a surprisingly small unit - as long as you don't mind it only running for a few seconds.
This might not help answer your question, but thought you might be interested in an example application of EDLCs and LED technology. My guess is your best bet for decorative stuff is electrochemical cells. To get equivalent run time an EDLC needs to be many times bigger. The only real advantage for your needs would be if you plan to charge cycle it VERY often and don't want to ever have to replace the rechargeable battery.
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deadrx7conv
Enlightened
In solarcharged accent lighting, with batteries that aren't replaceable, a supercapacitor is a better choice. I've seen outdoor floor brick/tiles with supercapacitors instead of batteries. This allows the tile/brick to be cemeted, glued, or paved into place permanently. You wouldn't want to do that with a short life rechargeble battery.
For example(cool pictures):
http://www.greenlighttechnologies.co.uk/brochure.pdf
Problem with those supercaps is that you can short them out and create a pretty good spark, right through your hand. The oops factor is risky business. They deserve much respect when handling. I've never seen a supercap explode. But, I've detonated plenty of smaller regular caps. So, be double careful with your power supply while charging.
Compare this to those silly 1F car stereo caps.
Stick with batteries for the floral arrangements.
For example(cool pictures):
http://www.greenlighttechnologies.co.uk/brochure.pdf
Problem with those supercaps is that you can short them out and create a pretty good spark, right through your hand. The oops factor is risky business. They deserve much respect when handling. I've never seen a supercap explode. But, I've detonated plenty of smaller regular caps. So, be double careful with your power supply while charging.
Compare this to those silly 1F car stereo caps.
Stick with batteries for the floral arrangements.
Besides that fact that this cap is huge (if that is inches on the ruler), you cannot neglect the Voltage.
Power stored in a capacitor goes with the square of voltage.
So his 15V 1F cap stores more energy than a 25F 2.7V one. And it is also tons more sturdy (those modern ultra-caps are getting more and more fragile in terms of cycle count, discharge currents, etc)
Power stored in a capacitor goes with the square of voltage.
So his 15V 1F cap stores more energy than a 25F 2.7V one. And it is also tons more sturdy (those modern ultra-caps are getting more and more fragile in terms of cycle count, discharge currents, etc)
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