Super capacitors

[Richard Goodrich]

Like to see a blog on use of super capacitors - applications, etc.

[Mint.]

I wouldn't mind one too. I have no idea of their applications!

[Rerouter]

the main benifit for super-capacitors is they hold a significant amount of charge, while taking effectivly no time to reach full capacity, say you had a system of sensors you wanted to power for about half an hour, but only wanted to apply power during a single button press,

only way you could get the capacity in that time frame without some time controlled switch would be with a supercapacitor,

this is just an example, and probably not the best one either,

small details: high capacity, but self discharge is in days at best,

[Psi]

This is my favorite ultracapacitor video

[Neilm]

Love it - I really like his last comment...

Neil

[T4P]

This is my favorite ultracapacitor video

My favourite too . SERIOUS DAMAGE .

[Write_to_Smokegenerator]

love the Video ^^

On my current Project we  (me and a friend) want to use a 10F super cap for the supply of a Real Time clock

[saturation]

http://www.popularmechanics.com/technology/gadgets/4223118

Seems like the technology has quieted down, not sure why.  The cost of each cell is much higher than a NiMH.

The above is one of the few products I saw in the 2009 made with supercaps.  I own one, it works great and in theory the battery should last a lifetime and no problems with memory effects or cell refreshing.  The main drawback is watt/kg, so the whole drill has only half the life of a simple AA powered drill but its perfect for home touch up work and it charges in 45 seconds; the 90 seconds is misleading because the driver provides only practical torque down to 50% of its power, then its useless, so it has to be charged much earlier effectively having half the burntime advertised.

[Psi]

I plan to swap out my 12v car battery and try 6 of those 2.5V 2600F caps in series.

I can't remember the exact figure, but they have enough energy to turn the engine over for 10-20 sec before the voltage gets too low.
So as long as your engine is ok and doesn't require lots of cranking the caps will work fine as a car battery replacement.

However, if you leave your lights on it will run flat quicker than a car battery.
And it will self discharge a little faster than a battery. It's not too bad though, my ultracaps seem to hold a charge really well, even after 2 months.

But the advantage is you will never need to buy a new car battery. The capacitors should last for the entire life of the car.
And i imagine (though i've not tried it yet) that the engine should crank noticeably faster because you wont get the battery voltage falling under startermotor load that you get using a battery (normally it falls to 10V or so).
With the ultracaps it should get almost all of the cap voltage, which could be up to 14V.

Edit: I'm not sure if the ultra low ESR will cause any issues with the cars charging system. It's on my list of things to investigate, or i may just plug it in and cross my fingers.

[wkb]

Well, supercaps are being used to recover brake energy, which is in turn released when the car/bus/whatever accelerates again.  I would prefer that use over using them as a starter battery.

[T4P]

Well, supercaps are being used to recover brake energy, which is in turn released when the car/bus/whatever accelerates again.  I would prefer that use over using them as a starter battery.

Good luck going if your car is hard to start .

[sacherjj]

I plan to swap out my 12v car battery and try 6 of those 2.5V 2600F caps in series.

I can't remember the exact figure, but they have enough energy to turn the engine over for 10-20 sec before the voltage gets too low.
So as long as your engine is ok and doesn't require lots of cranking the caps will work fine as a car battery replacement.

However, if you leave your lights on it will run flat quicker than a car battery.
And it will self discharge a little faster than a battery. It's not too bad though, my ultracaps seem to hold a charge really well, even after 2 months.

But the advantage is you will never need to buy a new car battery. The capacitors should last for the entire life of the car.
And i imagine (though i've not tried it yet) that the engine should crank noticeably faster because you wont get the battery voltage falling under startermotor load that you get using a battery (normally it falls to 10V or so).
With the ultracaps it should get almost all of the cap voltage, which could be up to 14V.

Edit: I'm not sure if the ultra low ESR will cause any issues with the cars charging system. It's on my list of things to investigate, or i may just plug it in and cross my fingers.

I would combine the caps with a smaller car battery.  That gives you best of both worlds and serious cold cranking amps.

[SeanB]

If you are going to use supercaps I would recommend a high current inductor in the alternator lead, to reduce the current that passes through the diodes. Either that or buy a very heavy duty aftermarket unit, designed to charge bigger batteries with a split charger, as it will have hopefully better rated diodes ( alternator diodes lead a hard life, high current pulses, large transients and high temperatures, often all at the same time) and better cooling.

[T4P]

If you are going to use supercaps I would recommend a high current inductor in the alternator lead, to reduce the current that passes through the diodes. Either that or buy a very heavy duty aftermarket unit, designed to charge bigger batteries with a split charger, as it will have hopefully better rated diodes ( alternator diodes lead a hard life, high current pulses, large transients and high temperatures, often all at the same time) and better cooling.

And oddly the engine might probably go before the alternator diode .

[wkb]

Well, supercaps are being used to recover brake energy, which is in turn released when the car/bus/whatever accelerates again.  I would prefer that use over using them as a starter battery.

Good luck going if your car is hard to start .

Sure.  Didn't write they were using them for that did I?

[SeanB]

DaveS, the alternator on my work vehicle died earlier this year. Dead diodes would not keep battery charged. Cheaper to put in a replacement unit, and easier as well. opening the unit is a pain, they are literally glued together during assembly, so you need to use a lot of heat and brute force to undo bolts and nuts. Replacement parts are hard to get as well, only replaceable part is the regulator and brushes, as they are one unit with 3 bolts to remove. Of course that is still working. Grinder then 3 piles - Steel, copper and aluminium for recycling.

[T4P]

DaveS, the alternator on my work vehicle died earlier this year. Dead diodes would not keep battery charged. Cheaper to put in a replacement unit, and easier as well. opening the unit is a pain, they are literally glued together during assembly, so you need to use a lot of heat and brute force to undo bolts and nuts. Replacement parts are hard to get as well, only replaceable part is the regulator and brushes, as they are one unit with 3 bolts to remove. Of course that is still working. Grinder then 3 piles - Steel, copper and aluminium for recycling.

I would just change the alternator , good going !

[G7PSK]

I have just read that the military use them for starting tanks and submarines. But such power sources will lead to hand held energy weapons, would not surprise me if they already exist in a lab somewhere.

[Psi]

it wouldn't surprise me if all those surplus supercaps that electronicgoldmine sell from time to time came from military equipment.
Probably being replaced with newer larger supercaps.

[Write_to_Smokegenerator]

I found today something interesting:

http://www.slideshare.net/ResearchIndia/super-capacitor-buses-in-shanghai-5156990

looks quite nice to me, but has a many deficits compared to a commercial bus, however i like the idea.

[kodon]

I think sometimes supercaps are used to preserve memory. And I don't mean those huge supercaps, but like 1F 5.5V etc.
And oh, I've seen one of those supercap banks meant to be installed in car. It was a prototype for a racing application so you can install it in any orientation you like. But nowdays you have gel batteries so no need for supercaps anymore.

[Write_to_Smokegenerator]

I think sometimes supercaps are used to preserve memory. And I don't mean those huge supercaps, but like 1F 5.5V etc.

Yep, In my current project I use it instead of a Lithium battery for the RTC (the cost is about the same and I won't need to change it.)

[bobhaha]

I grabbed a few from the electricgoldmine sale a while back... they are hell fun to play with!

[Time]

Being a high voltage high energy guy - these caps excite me very little. They can't hold off much voltage and the technology maturation rate in this area is turning out to be quite slow. 

[kodon]

That would make a totally usable spot welder for your sheet metal works if you needed one
Hmm... perhaps I'll have to build one someday