[ausev] Ultracaps

[Jim Watson]

I found with some more research that the cap energy equation (
E=(.5)(f)(v^2) ) produces an answer in joules. Maybe this is common
knowledge. Anyway, I found that,
65 610 joules = 0.018225 kilowatt hours

I think this is the same answer that someone else came up with by dividing
by 3600.

Jim


P.S. Happy New Year


On Thu, Jan 1, 2009 at 1:45 PM, <tomsmail at wtez.net> wrote:

> faradiddity?
>
> faradiddity!!!!?
>
> How 'bout "condensoriness"?
>
> :-)
>
>
>
> --- mseningen at austin.rr.com wrote:
>
> From: Mike Seningen <mseningen at austin.rr.com>
> To: AustinEV News Announcements and General Discussion <ausev at austinev.org
> >
> Subject: Re: [ausev] Ultracaps
> Date: Thu, 01 Jan 2009 11:55:52 -0600
>
>
> I think when I was looking at UltraCaps last summer they only had 2V
> UltraCaps ... so to get 200V
> you needed 100 in series, but then that would drop your CAP by a factor of
> 100!
>
> You also have to worry about the resistance of 100 in series.
>
> Having a 15V UltraCap with the same capacitance is also a huge win.
>
> My project was to convert a sports car to ICE comparable performance at
> a reasonable budget -- sort of having all 3 points of a triangle ---- so I
> had
> my work cut out for me :-)
>
> I was thinking about having a hybrid pack that had some sort dual pack --
> one for long term
> energy and the other for short bursts for acceleration.  AGMs and UltraCaps
> were
> considered for the short bursts, and LiFePO4 for high density, longer range
> storage.
>
> I didn't get very far.....
>
> Mike
>
> Gil Dawson wrote:
>
> On Dec 31, 2008, at 10:09 A, Jim Watson wrote:
>
>
> I don't know very much about Caps,.. But I do know that they don't
> take very long to store a charge,...
> Jim
>
>
> Turning it around, you might have put it, "They charge very quickly."
>
> On Dec 31, 2008, at 8:46 A, Brian Lasseter wrote:
>
>
> I prefer some of the Ultra-caps from Maxwell
> Technologies.  You can get nice 15V, 50F caps for $200.  (In a form
> factor about the size of two fists.)
>
>
> 15V is new, I think.  The highest max voltage I had noticed before
> was 2.
>
> The energy stored in a capacitor rises with the square of the
> voltage, so this is huge.  A 15V capacitor can store (225/4=) over
> FIFTY-SIX TIMES as much energy as a 4V capacitor of the same
> faradiddity.
>
> To compare some very rough theoretical maxima...
>
> A 12V battery rated at 200Ah can store at most    12 * 200 = 2,400
> watt-hours
>
> A 2V 50F capacitor can store    (0.5) * (50) * ( (2) ^ 2 ) =   100
> watt-hours
>
> A 15V 50 F capacitor can store (0.5) * (50) * ( (15) ^ 2 ) = 5,625
> watt-hours
>
> Now, that's getting somewhere.  (Somebody please check my figures.)
>
> On Dec 31, 2008, at 12:17 P, Jim Watson wrote:
>
>
> I just looked at the data sheet on a 500.0 F, 16.2 V cap. It says
> that it was designed for car applications. Also this cap that I
> looked at was around 5.75 kilograms = 12.67 lbs.
>
> E = (.5)(500)(16.2)^2
> I think that is:   E=64,000 WH   ??
>
>
> I concur (I get 65,610 wh.)  That's 10 times the Farads and a squeak
> more voltage than Jim's example above, so it checks.  I'm telling
> you, this is new.  I looked all over the web (OK, it was a year ago)
> and 2V was the max I saw.
>
> On Dec 31, 2008, at 12:17 P, Jim Watson wrote:
>
>
> What would charging this baby look like?? Would you just plug it
> into the wall for less than a fraction of a second, and be ready to
> go?
>
>
> Not quite.  They probably have a max amp rate through the connectors,
> and you'd be limited by your power supply rating.  But there's none
> of that chemical coddling that batteries require.  They'll probably
> let you flow full current from zip to max.  Recharging an UltraCap
> can't be anywheres near so slow as charging batteries.
>
> Contemplate these numbers for a minute.  More energy than can be
> stored in ten car batteries, in a device that weighs less than 13
> pounds and takes but a few minutes to charge.  What could you do with
> that?
>
> From: http://www.priusownersgroup.com/?p=2989
>
> [A]n ultracapacitor-equipped Toyota Supra HV-R coupe became the
> first hybrid to win the 24-hour endurance car race held at Japan's
> Tokachi International Speedway. The hybrid Supra finished 616 laps
> of the 5.1-kilometer (roughly three\u0013mile) course—19 more laps than
> the second-place nonhybrid Nissan Fairlady Z. "The Toyota that won
> was able to deliver energy more quickly, accelerate faster, and use
> braking generation more efficiently," says Kevin Mak, an analyst
> with research and consulting firm Strategy Analytics and author of
> a recent study that explores the potential for ultracapacitors to
> complement and possibly even replace batteries in hybrid vehicles.
> "The days of the large hybrid vehicle battery pack may be
> numbered," he adds.
>
>
> On Dec 31, 2008, at 12:17 P, Jim Watson wrote:
>
>
> "all of these products will perform reliably for more than one
> million discharge-recharge cycles." What does that bit about one
> million discharge recharge cycles mean?? Does it mean that one full
> trip in you car completing 1 full charge of the caps is = to 1 out
> of the million charges possible.
>
>
> That is how I read it.  Compare to a battery... you get, what?
> Hundreds, thousands at most?  Ultracaps are qualitatively different
> on this point.
>
>
>
> Damn that sounds great!!!
>
>
> Yes, doesn't it?
>
> So, what's their downside?  Anybody know?
>
>
>
> --Gil
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