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Super capacitors

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Overclocked

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Do Super capacitors have the same characteristics like normal Capacitors? Can they be discharged rapidly like normal capacitors?
 
Overclocked said:
Do Super capacitors have the same characteristics like normal Capacitors? Can they be discharged rapidly like normal capacitors?

Well they are capacitors, but I don't believe they can discharge at high rates, too high of a ESR. They are really designed for low current standby power.

However I read recently about a new 'super super capacitor' being developed for electric cars that may eliminate the need for large and expensive batteries, just charge up at home and off you go. Some start-up company in Texas I think, has been attracting venture caps and supposedly have patents and such. Good article but I didn't bookmark it.

Lefty
 
Leftyretro said:
However I read recently about a new 'super super capacitor' being developed for electric cars that may eliminate the need for large and expensive batteries, just charge up at home and off you go. Some start-up company in Texas I think, has been attracting venture caps and supposedly have patents and such. Good article but I didn't bookmark it.

So you replace a large expensive battery with a larger more expensive capacitor? :p

Somehow I can't get over the thought it's yet another money making scam?.
 
I've used super caps in applications where secure shutdowns are required.


i.e. Applications that write to SD cards periodically - You don't want to corrupt data by a user initiated power disconnection/switching off, instead the super cap can keep the low powered devices running to ensure everything can stop/save cleanly
 
That new super cap company, if their claims are true, really has fixed the electric car problem.

They basically claimed to have at least as good if not way better energy density than batteries and much higher power density. Also they basically have unlimited life (charge/discharge cycles) compared with the limited life of current battery technology (those NiMH's in all the hybrids are going to be a few grand each to replace in a few years). There are trains in China that run off super caps and charge at each station when they stop. What this company claimed IIRC was that charging up the caps was going to essentially give you the range of a normal tank of gas. Charging it would be the hardest part.
 
speakerguy79 said:
That new super cap company, if their claims are true, really has fixed the electric car problem.

If they have they wouldn't have any problems finding investors, I just hope it's so.

There are trains in China that run off super caps and charge at each station when they stop.

I suspect it's probably more likely it's full of Chinese men with pedals! :p

I would be dubious about China leading the world in anything technological.
 
Nigel Goodwin said:
If they have they wouldn't have any problems finding investors, I just hope it's so.



I suspect it's probably more likely it's full of Chinese men with pedals! :p

I would be dubious about China leading the world in anything technological.


Are you serious? China's economy is booming, to even assume for a second that they aren't good with technology is sheer ignorance.
 
TrevorP said:
Are you serious? China's economy is booming, to even assume for a second that they aren't good with technology is sheer ignorance.

There's a difference between being 'good with technology' and 'initiating new technologies' - I don't consider China any good at the second.
 
It's called EEStor. here's one article **broken link removed**

I saw a news item recently that they pushed back their ship date. I don't think this qualifies as a scam since it's based on credible science but there are clearly serious impediments. It's one thing to demo in the lab, it's another to replace a Prius' Battery with one of these. And it's a further thing to manfuacture in quantity at a cost effective price. I wish them success.
 
I saw a pic of the ZENN car in January. It will be the smallest, lightest and flimsiest car in North America.
 
Overclocked said:
Do Super capacitors have the same characteristics like normal Capacitors? Can they be discharged rapidly like normal capacitors?

Super caps are relatively new technology compared to regular caps and so each manufacturers models tend to be very different in many ways from those of other manufacturers. There are several makers who specifically recommend their supercaps for high discharge rates. I believe the AVX lineup ( https://www.electro-tech-online.com/custompdfs/2007/10/bestcap.pdf ) of supercaps should work well in this kind of application. There are many others out there, and it is best to study their datasheets to answer your question. The ESR spec is critical, and usually the supplier will specifically address whether their supercap is suitable to high discharge rates or not, usually in the applications notes section of the data sheet.

My experience is that supercaps do indeed work more like capacitors than they do like batteries. In other words, there is no memory effects, you can charge them up about as fast as you can discharge them, and they suffer few internal losses. However, they start behaving differently depending on how fast you are trying to push current in and out of them, in other words do not assume they work like most capacitors as the frequency of current in the application goes up. I have not tried them in any high frequency applications.
 
RadioRon said:
Super caps are relatively new technology compared to regular caps and so each manufacturers models tend to be very different in many ways from those of other manufacturers. There are several makers who specifically recommend their supercaps for high discharge rates. I believe the AVX lineup ( https://www.electro-tech-online.com/custompdfs/2007/10/bestcap-1.pdf ) of supercaps should work well in this kind of application. There are many others out there, and it is best to study their datasheets to answer your question. The ESR spec is critical, and usually the supplier will specifically address whether their supercap is suitable to high discharge rates or not, usually in the applications notes section of the data sheet.

My experience is that supercaps do indeed work more like capacitors than they do like batteries. In other words, there is no memory effects, you can charge them up about as fast as you can discharge them, and they suffer few internal losses. However, they start behaving differently depending on how fast you are trying to push current in and out of them, in other words do not assume they work like most capacitors as the frequency of current in the application goes up. I have not tried them in any high frequency applications.

You pretty much hit the nail on the head, I was worried about them being ruined after a couple discharges..

Well, they will be operated at DC, and just be charged and discharged rapidly to power a coil. It would be nice to know that I could use these instead of 50 caps in parallel...

I was going to get these, but as you see there is no data for them.
https://www.mpja.com/prodinfo.asp?number=16828+CR
https://www.mpja.com/prodinfo.asp?number=15990+CR

Both are the same but different colors.
 
Powerstor sells low ESR devices. The largest of their "A" line products is a 4.7 farrad capacitance with an ESR of .025 ohms. The ESR is slightly higher for DC Something like .04ohms but the voltage is really low 2.5 (3 max) so for pulse discharge applications you really have to spend some time desiging the circuit to figure out the best component values needed.
 
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