Capacitor storage

[Sunking]

Capacitors are wonderful on paper, useless as energy storage. The only useful application is EV Regen Braking. Batteries cannot absorb Regen Braking fast enough. With Caps you can recover some of that energy, and spend it on acceleration.

Only way to use it on a battery is to charge it up to 500 volts, then you can discharge down to 50 volts, or use a very complicated buck boost converter as EEbackwoods speaks of.

[DanKegel]

You could put a bidirectional buck/boost converter between the caps and the battery to push the voltage up when the caps discharge below the 48V battery, and then drop the 48V down to recharge the discharged cap. The problem is with the tremendous currents involved...

FWIW, scholar.google.com/scholar?q=ultracapacitor pulls up an avalanche of related papers.
With all that interest, some clever engineers somewhere are bound to come up with good uses for the darn things, despite the challenges.
(Power conversion engineers don't get those pointy hats with the moons and stars on them for nothing!)

[Mike90250]

FWIW, scholar.google.com/scholar?q=ultracapacitor pulls up an avalanche of related papers.
With all that interest, some clever engineers somewhere are bound to come up with good uses for the darn things, despite the challenges.
(Power conversion engineers don't get those pointy hats with the moons and stars on them for nothing!)

Dude, put on a pointy hat and sit in the corner.

You just don't get it, Mr Pie In The Sky. I'm sure the Flat Earth folks have an avalanche of papers too, but if it's junk, it's only good for propping up a table with a bad leg.

Caps are good for storage. Batteries are better for utilizing the storage. As Sunking said, our most useful application for caps, is EV regen braking. Otherwise, you skim the cream of the charge off the top 1% of the cap, and the rest is useless. Someday (but I'm not holding my breath) there may be a more useful high energy app for them, but currently, they are no good for EV's or home storage. Sure, you can start a car with some, but a battery is better.

super caps have been around a long time, and many, many folks have found great applications for them (batteryless storage for remote sensors) but house & EV power is not there yet.

[DanKegel]

As Sunking said, our most useful application for caps, is EV regen braking.

Heh. I think it was me that pointed that out to him, back on page one of this thread.... and he was very confused about what happens when you connect capacitors in series. I don't think he's forgiven me yet for being right on either of those points

[Sunking]

Heh. I think it was me that pointed that out to him, back on page one of this thread.... and he was very confused about what happens when you connect capacitors in series. I don't think he's forgiven me yet for being right on either of those points

You are a moron and have no clue what you are talking about. You have no clue what happens when you connect caps in series. You loose Capacitance. You just proved again you are an IDIOT.

[max2k]

I'm not. Just like you, I noticed a discussion about them, and replied with an interesting tidbit. I hadn't thought about them since, oh, the last time this thread was active.

Let's blame BackwoodsEE then - he resurrected this thread and it looks like some things better be left alone.

[Sunking]

Let's blame BackwoodsEE then - he resurrected this thread and it looks like some things better be left alone.

Yep which backs up what I said and anyone who knows anything about capacitors. With an energy density of 1 to 10 wh/Kg makes them useless. Throw in all the other crap like voltage balancers to over come the low voltage nature needed to make them work eliminates them as any practical solution. One thing that Dan really likes is the cost. Using Lead acid batteries cost you you roughly $100 to $200 Kwh which is outrageous enough. Want Lithium and the cost doubles the quadruples. to $400 to $800 Kwh. Use Supercaps and now you jumpt to several thousand dollars per Kwh. No one could afford to use electricity, and no one could afford any products made from electricity. Dan wants to destroy economies.

If it is not to destroy economies would mean Dan is an idiot and does not have a clue what he is talking about. . Take your pick.

[max2k]

Can you explain again how it is that connecting capacitors in series decreases the amount of energy they store?

it doesn't and it was settled in this thread several times, give it a rest.

[Sunking]

Right, but Sunking still thinks it does, and is calling me an idiot because I don't believe him.

Everyone thinks you are an idiot and do not know what you are talking about. You are just to clueless to believe the vote. As Max points out you completely missed the point again to push your false agenda.

Here is what you do not understand, and most other people do understand. Today you can go buy a Capacitor Starting battery for $970 dollars. Just a few very important details one needs to know to make a purchase deciseion other than the outrageous price. It comes right from the manufacture.

Capacity is 3 seconds at 1800 amps. If your engine does not start, call a tow truck, the CAP is dead. If we translate 3 seconds at 1800 Amps tells us the battery capacity is 3 / 3600 x 1800 Amps = 1.5 AH. The battery is a BCI 31 Class. A good Lead Acid version of this battery has a capacity of 40 to 50 AH. If we translate that to Energy or Watt Hours, the SuperCap Dan Idiot Battery cost $970 \ 18 Watt Hours = $52.88-Wh. Compare that to say a good Exide Pb battery cost is $72 / 480 Wh = $0.15 - Wh. Dan I know you are not good with math so allow me to help you out here. Your Super Cap battery cost $52/$.15 = 346 times more than a Pb battery. Now I realize you do not think that is a big deal. Trust me, all the rest of the world thinks that is a HUGE PROBLEM.

But there is also one more catch. Your vehicle has to be REWIRED. It has to be rewired so there are no Phantom Loads to discharge the Super Cap. Say your vehicle clock or keyless entry system are examples of Phantom Loads. Why because the SuperCap has less capacity than flash light battery. A Pb battery has roughly 500 Watt hours compared to 18 wh. Again allow me to help you with the math. A Pb battery has 500/18 = 27 times more capacity @ 1/346 the cost.

Now lets get right down to efficiency. You say 100% right. You are an idiot. A PB battery round trip efficiency is roughly 80%. Certainly not great. Again right from the manufacture data it states the Super Cap takes 20 minutes @ 10 Ah. So lets do some math shall we. 20 minutes = .3333 hours so .333 hours x 10 amps = 3.33 AH Input. Output capacity = 1.5 AH. Again Dan I know math is not your thing but them means the efficiency is 1.5 / 3.333 x 100 = 45%. Not quite that 100% you are squawking about. Even 45% is putting shinola on a turd because that only speaks of AH charge efficiency, not Energy Efficiency. Those AH go in at 16.2 volts and come out at 7.2 volts. 16.2 volts x 10 amps x .33 hours = 53 watt hours input, Output is 7.2 volts x 1800 amps x .000833 hours = 10.8 watt hours Now we are getting down to less than 20% or less. Dan that means you burn 5 units of energy to get 1 unit out in a real product in the Real World of application. Why such a low efficiency? Like I said earlier .ESR = 002 Ohms on a 1000 Fd cap. Result is 1800 amps for 3 seconds to DEAD. Only a idiot would buy or want such a product.

It does have one good application. Regenerative Breaking. Good for very short burst of energy that you discharge very quickly immediately before it leaks out. Hit the break, store that energy, then release it when you disengage the break and accelerate. But the gain is small with such low efficiency that would have not been used otherwise burnt off as heat on you break linings and pads. Completely useless and a waste for energy storage. It gets you an extra mile on a charrge and saves the breaks some wear and tear.

Max is right, you should shut up and go away because you are an idiot. Math proves it. You just got your butt kicked again.
\
\

[max2k]

SK, what are you talking about? Who would rewrite their own car to add regen braking? I certainly never suggested anything like that.

Seems like you're assuming I'm an idiot, making up stuff that an idiot might say, and attributing it to me.

Meanwhile, you still don't seem to understand that connecting capacitors in series doesn't reduce the amount of energy they store. (Or do you, and I'm just misunderstanding?)

you're misunderstanding can we close this thread for all other uninitiated souls ?

[Sunking]

SK, what are you talking about? Who would rewrite their own car to add regen braking?

You just proved you are an idiot. You cannot even read. How do you rewrite a car for regen braking? That is complete nonsense.

What I said is if you use the SuperCap starting battery requires you to rewire your car wiring system to stop phantom loads from discharging a useless POS SuperCap battery. It is as clear as day in the manufacture's own instructions. That has nothing to do with REGEN Braking in an Electric Vehicle.

[Sunking]

A clever engineer cannot change the law of physics. . I said supercaps will never be used for energy storage because of the physics. I never said they do not have an application, you just made that up. I gave one example, Regen Braking. Proves you cannot read and know nothing about the technology. You just like getting beat up like you did when you were a kid in school.

[J.P.M.]

you're misunderstanding can we close this thread for all other uninitiated souls ?

Kind of like watching Mike Tyson beat up a drunk, huh ?

Or a train wreck - you can't not watch.

Or, don't read the posts - Change the channel and watch the soaps instead.

[Mike90250]

Another valuable thread contaminated and killed by Dan.