Yup, supercaps are good for extremely high current draw at hundreds of amps, but have really poor capacities compared to chemical storage.
Some people use it to hook it up in parallel with their car batteries to support while driving uphill or using the A/C, but I don’t see it replacing them soon.
Although the capacitor in that video is only 1 Farad, more what he could find locally. Sounds like he had a solar project for a Kindle. The capacitors have a much lower internal resistance.
Another video the guy got 277 ma out of a couple super capacitors. If my math is right, that would give me 5 minutes or so at 3 amps on XML t6. Enough to look around the yard. Although the voltage was low on part of that
Depends on how you plan on using them. If you need something that can charge fast and discharge VERY fast, and don’t much care about runtime…. nothing else will do.
For more mundane uses, batteries still seem to win.
Supercapacitors has way to low capacity for usage in flashlight and to high self discharge.
Some years ago they where often uses as memory backup, while people replaced batteries (Today most stuff has flash memory, that remembers without power).
Today they are used for short time storage and very high power peaks.
What kind of voltage does a capacitor have?
I would not mind a 18650 or 26650 compatible capacitor (even if i need spacers) that i can charge in a few secs (with a specialized charger i assume) that gives me 5-10 minutes of runtime even at 1.5A because i can leave it empty, charge it, use it and leave it till the next time i need it (and the cycle repeats) and i put no wear on my lithiums, it would suffice for 60-75% of my needs.
Usual super capacitors is 2.5 or 2.7 volt, the older generation memory backup was higher. If you uses more capacitors in series you need a balancing circuit or you risk damaging them due to reverse charge.
Capacitors does not have a fixed voltage when discharging, they have a linear discharge curve from maximum down to 0. I.e. a 2.5 volt capacitor is down to half charge when the voltage is 1.25 volt.
I would love to use capacitors in place of our normal cells. Last time I researched it, the issue was that voltage drops as the electricity in the cap is drawn out. Unlike a cell that produces a relatively stable voltage from the chemical reaction that takes place as they discharge.
It seems you would need the all of following for in order to get usable run times:
High capacity capacitor
A special buck/boost driver with a large input range on voltage
A low current application
I haven't looked into in a very long time. Maybe there have been some advances that I'm not aware of.
That’s what I’m thinking. It should be doable to get 150 mah out of 2 or 3; 400 farad capacitors. That should give you 6 min. at 1.5 amp. Usually enough time around the house. Plus you should be able to plug in
Can anyone recommend a driver? I’m think between 1.2 –2V to 5V? I suppose the driver could go higher/ lower, but to handle that voltage.
So one large cell and a specialized boost driver would be needed, no point adding the extra complexity of multiple cells
Do they come in 26mm diameters?
I assume no one has created such circuitry, so we would need someone to design it
A company called Storedot is working on supercapacitors that should have the energy capacity of todays lithium ion batteries but with supercharging times of only 30seconds. I guess we will have to wait 3 years to see if they are right.