Ultracaps may be the future Battery!

[Tanstaafl]

There I was thinking your name was Tan Staafl

(Staafl being some sort of German surname)

There Ain't No Such Thing As A Free Lunch

 

[Ludwig II]

On the other hand, you don't have to throw half of what you did get into the bin.

 

[slickdude]

Well they are coming along. I talked to Li Ping of Ping batteries and he said they are closely watching this technology. He pointed out that current affordable caps hold a certain amount of energy for so long. So the technology is there and devloping. Meanwhile I found some vids of people experimenting with ultracaps on their own. Check the vids out. The future couldn't be brighter

http://www.youtube.com/watch?v=exwd-tswyzA

http://www.youtube.com/watch?v=6h_XPz-GKS4

http://www.youtube.com/watch?v=SJfRZJpmUrM

 

[libranskeptic]

I'd heard about them before, but this got me interested in taking a closer look.

Ultra-capacitors aren't really suitable to replace batteries; while they have can store lots of energy and release it quickly, their energy density is less than lithium ion batteries (but greater than SLA batteries.)

They also have issues dealing with their discharge characteristics; the voltage drops steadily over time, unlike batteries, which stay fairly constant until they near their capacity, then start dropping rapidly. Since each ultracap has a low maximum voltage, they must be used in series, which cuts the storage capacity of the capacitor as a whole. For instance, if you want to store 12V in an ultra-capacitor 'pack', using the 3000 farad UTs mentioned in the article, you would need to place 5 in series, which reduces the capacitance of the pack as a whole to 600 farads. Then charge this pack to 12 volts. If you then pull 10 amp out of the pack, in 12 minutes, the voltage has dropped to 4.44V, and in another 12 minutes, it has dropped to 1.6 volts.

Since the output voltage steadily drops as the cap discharges, you need buck-boost regulators to convert the output voltage from the ultracaps into the steady voltage needed for most loads, which limits the efficiency to about 70%.

What is more likely, is that designers will start using ultracaps in conjunction with lithium ion batteries in a hybrid system, using the ultracapacitor packs (ultrapacks) for quick storage and quick release power needs (with lower losses, compared to the chemical reaction losses associated with batteries.)

Regenerative braking, for instance, would be a great use for them; power is stored in the ultrapack as you brake or go downhill, then released from the ultrapack during acceleration. This means that your li-ion batteries aren't being asked to supply the heavy currents during acceleration (most of the time,) but instead, can be sized more towards the 'average' loads.

quite so. well put. Just as we have hybrid plugins, we will have hybrid storage for them. Each storage option has its proS and conS, so form a team of differing technologies and use the strengths of one to cover the weakness of another technology?

As you say~, caps would e.g. make regen a reality given caps can accept fast dumps of charge.

A kwh of lifepo4 and 10 minutes of 1 kw in caps would be durable and effective storage greater than the sum of the parts.

 

[skyash]

Whats the battery pack on tv jump starting cars.li carbine. Or something. Fits in your pocket

 

[HeadSmess]

what noone mentions when they say caps can charge instantly (they can charge and discharge in the MHz frequencies!) is the amount of current they require to do so...

which then leads to power line problems...there simply isnt the infrastructure in place to supply such heavy demands.

really, if the electric vehicle is to get anywhere at the moment, we have to think about using something similar to the battery packs in a drill. make them a standard (like CD's, or USB, or similar) so you just pull up to a service station, pull out a box, push another one in place... need more juice for extended trips? theres room for several of them... the boxes (batteries) can sit there on charge, trickling away, moderate power line loads, while you can be on your way in just a few seconds

small enough for little tina with her freshly painted nails to swap them herself...

not too mention the home charger, the panels on the roof, bonnet and every other surface...

still, thermal storage beats electric storage hands down.

 

[libranskeptic]

To me your logic seems fundamentally flawed on point one, though i know little of the nuances of capacitors.

The point is, caps can take ~whatever you can feed them and store it (and extremely efficiently i think?), as opposed to batteries which you can only slow charge. The problem is not that we cant charge capacitors at the maximum possible rate. Who cares? They fill an important gap in the abilities of batteries - short powerful dumps - in or out, at about 20x the cost i hear for super caps (which are pretty mainstream now - just combining nanotubes and traditional capacitors for extra squirt - much as batteries have advanced).

further sir, "
still, thermal storage beats electric storage hands down.
" seems a broad statement. Care to elaborate?

 

[HeadSmess]

yes, a capacitor can just as easily be slow charged.

they still havent gotten supercaps to contain anywhere near the same power as a battery can. batteries are chemical, capacitors are simply numbers of electrons. the more surface area, the thinner the dielectric, the more capacitance... at the sacrifice of voltage. so they tend to have rather limited operating voltages.

its also good to be aware that the design of capacitor affects charge and discharge rates. 3km of super thin foil, separated by a thin mylar membrane from another 3km of foil, wound tightly into a coil and stuffed into a can, still only has one small wire connected in one place. the current has to travel all the way down that foil (typical caps, super caps use "spongy" conductors to increase surface area, therefore electrons stored, plus a strange sort of insulating layer attached to said conductor) to be of any use.

the maximum current available is then limited by that conductors capabilities, as is maximum charging current. make the conductor bigger to take more current? increase the total size of package. increase insulation to increase voltage? bigger again!

this all has adverse affects upon the working frequency, etc...not that frequency is an issue with straight DC energy storage.

a battery is slow to charge because it has to "undo" the reaction that creates the electricity in the first place. atoms are moving, chemicals are changing!

a capacitor only has to move electrons around...but they still have to move THROUGH something.



thermal storage...it is very easy to insulate something to store heat energy. no nasty chemicals required!

unfortunately, using the heat is another matter entirely... peltiers should be developed more. as should nano sized stirling generators, which are the most efficient convertors of heat into other useful energy.

and virtually all large powerstations still run steam engines. perfectly suited to using stored heat (solar, geothermal) as easily as gaining it from nukes or coal.

this here is 3000farads! huge!

5.5 inches long by 2.5 inches round.

(now, i have some 450 volt electro caps here, same size roughly, but theyre only good for 330 uF or MICRO Farads...)

that is about 1100 amps for 1 second! (a farad is an amp for 1 second at 1 volt, from memory, i could be very very wrong...please tell me if so )

or, 8.1kw/second. 3000x2.7.... or I*V...

for 1 second!

not an hour, not ten minutes... 1 second!


you need how many to create 48 volts?

and you would need how many to produce a constant 8A for an hour?

they are mainly used when a very large current is required...for a short time only.


as said, a lot of what i say comes from my memory, i could be very very wrong... but still, i hate to think what a pack containing 20 of these would weigh...or how big it will be.

ill stick to Lithium based battery tech for a while longer

 

[libranskeptic]

yes, a capacitor can just as easily be slow charged.

they still havent gotten supercaps to contain anywhere near the same power as a battery can. batteries are chemical, capacitors are simply numbers of electrons. the more surface area, the thinner the dielectric, the more capacitance... at the sacrifice of voltage. so they tend to have rather limited operating voltages.

its also good to be aware that the design of capacitor affects charge and discharge rates. 3km of super thin foil, separated by a thin mylar membrane from another 3km of foil, wound tightly into a coil and stuffed into a can, still only has one small wire connected in one place. the current has to travel all the way down that foil (typical caps, super caps use "spongy" conductors to increase surface area, therefore electrons stored, plus a strange sort of insulating layer attached to said conductor) to be of any use.

the maximum current available is then limited by that conductors capabilities, as is maximum charging current. make the conductor bigger to take more current? increase the total size of package. increase insulation to increase voltage? bigger again!

this all has adverse affects upon the working frequency, etc...not that frequency is an issue with straight DC energy storage.

a battery is slow to charge because it has to "undo" the reaction that creates the electricity in the first place. atoms are moving, chemicals are changing!

a capacitor only has to move electrons around...but they still have to move THROUGH something.



thermal storage...it is very easy to insulate something to store heat energy. no nasty chemicals required!

unfortunately, using the heat is another matter entirely... peltiers should be developed more. as should nano sized stirling generators, which are the most efficient convertors of heat into other useful energy.

and virtually all large powerstations still run steam engines. perfectly suited to using stored heat (solar, geothermal) as easily as gaining it from nukes or coal.

this here is 3000farads! huge!

5.5 inches long by 2.5 inches round.

(now, i have some 450 volt electro caps here, same size roughly, but theyre only good for 330 uF or MICRO Farads...)

that is about 1100 amps for 1 second! (a farad is an amp for 1 second at 1 volt, from memory, i could be very very wrong...please tell me if so )

or, 8.1kw/second. 3000x2.7.... or I*V...

for 1 second!

not an hour, not ten minutes... 1 second!


you need how many to create 48 volts?

and you would need how many to produce a constant 8A for an hour?

they are mainly used when a very large current is required...for a short time only.


as said, a lot of what i say comes from my memory, i could be very very wrong... but still, i hate to think what a pack containing 20 of these would weigh...or how big it will be.

ill stick to Lithium based battery tech for a while longer

Good post. Ta. Makes a few things clearer.

Or put simply, supercaps are ~currently about 20x dearer for storage and 10 x the volume. But thats ok, thats not everything. Their future seems as part of a hybrid approach to storage (even combining both within the same cannister cell is a happening thing). A bit of both.

again, i am not technical, but take regen, which i suspect mostly is a nonsense now cos the power dumps cannot be absorbed by the battery. Even a very small bank of capacitors could absorb a power dump and immediately begin emptying itself at a lesser (~.4c) rate into the battery storage or prioritised for use by the motor, so it is quickly available for re-use. If the bike stops, the capacitors fill from the battery, and whammo, the first 5kph of acceleration is powered by a burst from the capacitors. Easy.

you are right to stress that the battery is a chemical reaction to be nursed along, not just an electric dial or switch. Its easy to forget. They really hate being stressed by big dumps in or out. Caps love them, and make great little helpers for the heavy lifting.

I intuitively suspect 24v has its merits if ~500 watt per motor (judging from listings i recall) is ok. The lower voltage would seem more suited to capacitors also?

 

[libranskeptic]

yes, a capacitor can just as easily be slow charged.

they still havent gotten supercaps to contain anywhere near the same power as a battery can. batteries are chemical, capacitors are simply numbers of electrons. the more surface area, the thinner the dielectric, the more capacitance... at the sacrifice of voltage. so they tend to have rather limited operating voltages.

its also good to be aware that the design of capacitor affects charge and discharge rates. 3km of super thin foil, separated by a thin mylar membrane from another 3km of foil, wound tightly into a coil and stuffed into a can, still only has one small wire connected in one place. the current has to travel all the way down that foil (typical caps, super caps use "spongy" conductors to increase surface area, therefore electrons stored, plus a strange sort of insulating layer attached to said conductor) to be of any use.

the maximum current available is then limited by that conductors capabilities, as is maximum charging current. make the conductor bigger to take more current? increase the total size of package. increase insulation to increase voltage? bigger again!

this all has adverse affects upon the working frequency, etc...not that frequency is an issue with straight DC energy storage.

a battery is slow to charge because it has to "undo" the reaction that creates the electricity in the first place. atoms are moving, chemicals are changing!

a capacitor only has to move electrons around...but they still have to move THROUGH something.



thermal storage...it is very easy to insulate something to store heat energy. no nasty chemicals required!

unfortunately, using the heat is another matter entirely... peltiers should be developed more. as should nano sized stirling generators, which are the most efficient convertors of heat into other useful energy.

and virtually all large powerstations still run steam engines. perfectly suited to using stored heat (solar, geothermal) as easily as gaining it from nukes or coal.

this here is 3000farads! huge!

5.5 inches long by 2.5 inches round.

(now, i have some 450 volt electro caps here, same size roughly, but theyre only good for 330 uF or MICRO Farads...)

that is about 1100 amps for 1 second! (a farad is an amp for 1 second at 1 volt, from memory, i could be very very wrong...please tell me if so )

or, 8.1kw/second. 3000x2.7.... or I*V...

for 1 second!

not an hour, not ten minutes... 1 second!


you need how many to create 48 volts?

and you would need how many to produce a constant 8A for an hour?

they are mainly used when a very large current is required...for a short time only.


as said, a lot of what i say comes from my memory, i could be very very wrong... but still, i hate to think what a pack containing 20 of these would weigh...or how big it will be.

ill stick to Lithium based battery tech for a while longer

PS

re "
3km of super thin foil, separated by a thin mylar membrane from another 3km of foil, wound tightly into a coil and stuffed into a can, still only has one small wire connected in one place. the current has to travel all the way down that foil
" - excellent - i kinda knew that, but but you have the wisdom to stress its fundamental significance to their difficulty with higher voltages. Much clearer now.