# [EVDL] UltraCapacitors



## EVDL List (Jul 27, 2007)

Hello ED,

I brought up the subject of SuperCapacitors, the first time I came on this 
list which could run a vehicle for a short distance that can be use for 
utility vehicles and buses that could run for about 10 to 15 miles.

The knee jerk reaction was that ultra capacitors would discharge all there 
energy in 15 seconds. I said these are super capacitors and have 
electrolytes like a battery but can be recharge in 15 minutes.

So I contacted these companies, to see what size and how many I need to run 
my EV which I only use for very short trips which is not more than 5 miles a 
day. For my vehicles that weighs 7000 lbs with batteries, would would weigh 
5500 lbs with super capacitors and have a range of 15 miles would cost about 
$40,000.00 which would be the last set of energy packs you will need.

I would not have to have a 300 amp charging station to charge them in 15 
minutes, but could use the standard PFC chargers and Zillas for this system.

Roland


----- Original Message ----- 
From: <[email protected]>
To: <[email protected]>
Sent: Friday, November 16, 2007 8:46 AM
Subject: [EVDL] UltraCapacitors


> You may have seen this one already -
>
> http://www.spectrum.ieee.org/nov07/5636
>
> Here it is again -
>
> Best Regards -
> Ed
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
> 

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

[No message]


----------



## EVDL List (Jul 27, 2007)

Interesting but really sloppy that they compare capacity with an 
unspecified batterytechnology!
25% of a battery. what battery??
25% of lead and it's useless, 50% of the absolutely best lithiums and it 
could be quite interesting.

Dan



> [email protected] wrote:
> > You may have seen this one already -
> >
> > http://www.spectrum.ieee.org/nov07/5636
> ...


----------



## EVDL List (Jul 27, 2007)

Hi Roland,

What ultracapacitors were you looking at? A couple months ago I did a
comparison of Maxwell ultracaps (bcap3000) and the A123 batteries. The
Maxwells were 5.52 wh/kg and the A123s were 80-110 wh/kg depending on
discharge. I got the idea that at this point in time (with A123
batteries at least sort of available from Dewalt battery packs) that
ultracapacitors were not worth it. Are there ultracaps out there
significantly better than the Maxwells?

Thanks,
Brian 

-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of Roland Wiench
Sent: Friday, November 16, 2007 8:22 AM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] UltraCapacitors

Hello ED,

I brought up the subject of SuperCapacitors, the first time I came on
this list which could run a vehicle for a short distance that can be use
for utility vehicles and buses that could run for about 10 to 15 miles.

The knee jerk reaction was that ultra capacitors would discharge all
there energy in 15 seconds. I said these are super capacitors and have
electrolytes like a battery but can be recharge in 15 minutes.

So I contacted these companies, to see what size and how many I need to
run my EV which I only use for very short trips which is not more than 5
miles a day. For my vehicles that weighs 7000 lbs with batteries, would
would weigh 5500 lbs with super capacitors and have a range of 15 miles
would cost about $40,000.00 which would be the last set of energy packs
you will need.

I would not have to have a 300 amp charging station to charge them in 15
minutes, but could use the standard PFC chargers and Zillas for this
system.

Roland


----- Original Message -----
From: <[email protected]>
To: <[email protected]>
Sent: Friday, November 16, 2007 8:46 AM
Subject: [EVDL] UltraCapacitors


> You may have seen this one already -
>
> http://www.spectrum.ieee.org/nov07/5636
>
> Here it is again -
>
> Best Regards -
> Ed
>

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

Hi Brian,

Maxwell are among the best Ultracaps available today. 
The paper that started this thread concerned the next
generation ultracap, using nanotube carbon, which
should increase the energy density 10 fold. Using
your numbers, that might explain the 50 percent vs
battery comparison mentioned.

Present technology ultracaps can compete with
batteries where you have a power application, instead
of an energy situation. I had a discussion on this
list with Bill Dube about 6 months ago on the subject.
If you can find that, you might find it interesting.

Ultracaps have worked very well in a parallel hybrid,
where the charge and discharge durations last from 7
to 20 seconds with power levels exceeding 150 kW. The
efficiency, temperature independence and cycle life
(1,000,000 plus) favor caps over batteries.

Regards,

Jeff M

--- "Gilbert, Brian D (GE Infra, Energy)"


> <[email protected]> wrote:
> 
> > Hi Roland,
> >
> ...


----------



## EVDL List (Jul 27, 2007)

The problem with capacitors is the linear voltage discharge curve. The 
voltage will decay and the controller/your foot will drain more amps to keep 
you operating (assuming you aren't at max) and this will cause an even 
faster non-linear (in the opposite way) voltage drop.

If you had a system that could use a very wide range voltage, then they'd be 
a good solution. My EV's converter drops out at 145v (216v nominal system) 
and the controller's internal power supply drops out at around 100v. So 
this would be a good chunk of stored energy in the caps that would be 
unusable.

Personally I think supercaps for stiffening, especially on chemistries that 
have high internal resistance, is the best current application.

-Phil
----- Original Message ----- 
From: "Roland Wiench" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Friday, November 16, 2007 8:22 AM
Subject: Re: [EVDL] UltraCapacitors


> Hello ED,
>
> I brought up the subject of SuperCapacitors, the first time I came on this 
> list which could run a vehicle for a short distance that can be use for 
> utility vehicles and buses that could run for about 10 to 15 miles.
>
> The knee jerk reaction was that ultra capacitors would discharge all there 
> energy in 15 seconds. I said these are super capacitors and have 
> electrolytes like a battery but can be recharge in 15 minutes.
>
> So I contacted these companies, to see what size and how many I need to 
> run my EV which I only use for very short trips which is not more than 5 
> miles a day. For my vehicles that weighs 7000 lbs with batteries, would 
> would weigh 5500 lbs with super capacitors and have a range of 15 miles 
> would cost about $40,000.00 which would be the last set of energy packs 
> you will need.
>
> I would not have to have a 300 amp charging station to charge them in 15 
> minutes, but could use the standard PFC chargers and Zillas for this 
> system.
>
> Roland
>
>
> ----- Original Message ----- 
> From: <[email protected]>
> To: <[email protected]>
> Sent: Friday, November 16, 2007 8:46 AM
> Subject: [EVDL] UltraCapacitors
>
>
>> You may have seen this one already -
>>
>> http://www.spectrum.ieee.org/nov07/5636
>>
>> Here it is again -
>>
>> Best Regards -
>> Ed
>>
>> _______________________________________________
>> For subscription options, see
>> http://lists.sjsu.edu/mailman/listinfo/ev
>>
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
> 

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

Well so far the biggest I've seen on the market were the Maxwell
Ultracaps- a low voltage, high farad, very low resistance device which
is many orders of magnitude better than anything made previously.

A fellow here did this burnout entirely on a huge bank of them:
http://www.haritech.com/Woodburn2005058.MOV
http://www.haritech.com/VictorWoodburn_divx.avi

He didn't do a 1/4 mi run because despite the impressive initial kick it
would have petered out long before the finish line.

There have been greater caps like the ESMA:
http://www.esma-cap.com/Products/Capacitor_cells/EC353/?lang=English

ESMAs are almost as tricky as regular batts. They can't be discharged
below a certain voltage (like lead-acids) and may require electrolyte
topping off.

A company called EEStor announced with a LOT of fanfare that they would
be able to produce a barium-titanium-nitride cap with so much energy
density you could replace the primary batts (like in the IEEE Spectrum
article). In fact they spec'ed a cap like 200 or 300 lbs that contained
the drive shaft energy equivalent of about 4.5 gal of gasoline! 
However, I guess it's years later now and no product has been publicly
demonstrated that I know of, not even on a small scale.

Indeed caps would have a serious problem with broad input voltage
changes from "full" to the last 10% or 20%. EEStor also spec'ed their
cap as being thousands of volts! This is impossible for current
controllers, a special-purpose controller would be necessary. For
EEStor's spec, it would not dip below 100V or 200V until it was >>90%
drained so it wouldn't need a "boost" to be able to drive the motor. A
100V cap would be a different situation unless several were in series. 
Boost converters have their own difficulties at high power levels. Also
there's significant problems in designing a high power buck controller
to use thousands of volts to drive a DC motor at some 50V or 100V, these
high "buck ratios" come with their own technical difficulties which are
difficult and expensive to address.

Danny

----- Original Message -----
From: Roland Wiench <[email protected]>
Date: Friday, November 16, 2007 10:23 am
Subject: Re: [EVDL] UltraCapacitors
To: Electric Vehicle Discussion List <[email protected]>

> Hello ED,
> 
> I brought up the subject of SuperCapacitors, the first time I came 
> on this 
> list which could run a vehicle for a short distance that can be use 
> for 
> utility vehicles and buses that could run for about 10 to 15 miles.
> 
> The knee jerk reaction was that ultra capacitors would discharge 
> all there 
> energy in 15 seconds. I said these are super capacitors and have 
> electrolytes like a battery but can be recharge in 15 minutes.
> 
> So I contacted these companies, to see what size and how many I 
> need to run 
> my EV which I only use for very short trips which is not more than 
> 5 miles a 
> day. For my vehicles that weighs 7000 lbs with batteries, would 
> would weigh 
> 5500 lbs with super capacitors and have a range of 15 miles would 
> cost about 
> $40,000.00 which would be the last set of energy packs you will need.
> 
> I would not have to have a 300 amp charging station to charge them 
> in 15 
> minutes, but could use the standard PFC chargers and Zillas for 
> this system.
> 
> Roland
> 
> 
> ----- Original Message ----- 
> From: <[email protected]>
> To: <[email protected]>
> Sent: Friday, November 16, 2007 8:46 AM
> Subject: [EVDL] UltraCapacitors
> 
> 
> > You may have seen this one already -
> >
> > http://www.spectrum.ieee.org/nov07/5636
> >
> > Here it is again -
> >
> > Best Regards -
> > Ed
> >
> > _______________________________________________
> > For subscription options, see
> > http://lists.sjsu.edu/mailman/listinfo/ev
> > 
> 
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
> 

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

Hello Brian,

These are SuperCapacitors, not UltraCapacitors. Assembly in cells like a 
battery with a electrolyte. See the esma-cap.com site for the info.

Have not talk with these people since the last decade.

Roland


----- Original Message ----- 
From: "Gilbert, Brian D (GE Infra, Energy)" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Friday, November 16, 2007 11:32 AM
Subject: Re: [EVDL] UltraCapacitors


> Hi Roland,
>
> What ultracapacitors were you looking at? A couple months ago I did a
> comparison of Maxwell ultracaps (bcap3000) and the A123 batteries. The
> Maxwells were 5.52 wh/kg and the A123s were 80-110 wh/kg depending on
> discharge. I got the idea that at this point in time (with A123
> batteries at least sort of available from Dewalt battery packs) that
> ultracapacitors were not worth it. Are there ultracaps out there
> significantly better than the Maxwells?
>
> Thanks,
> Brian
>
> -----Original Message-----
> From: [email protected] [mailto:[email protected]] On
> Behalf Of Roland Wiench
> Sent: Friday, November 16, 2007 8:22 AM
> To: Electric Vehicle Discussion List
> Subject: Re: [EVDL] UltraCapacitors
>
> Hello ED,
>
> I brought up the subject of SuperCapacitors, the first time I came on
> this list which could run a vehicle for a short distance that can be use
> for utility vehicles and buses that could run for about 10 to 15 miles.
>
> The knee jerk reaction was that ultra capacitors would discharge all
> there energy in 15 seconds. I said these are super capacitors and have
> electrolytes like a battery but can be recharge in 15 minutes.
>
> So I contacted these companies, to see what size and how many I need to
> run my EV which I only use for very short trips which is not more than 5
> miles a day. For my vehicles that weighs 7000 lbs with batteries, would
> would weigh 5500 lbs with super capacitors and have a range of 15 miles
> would cost about $40,000.00 which would be the last set of energy packs
> you will need.
>
> I would not have to have a 300 amp charging station to charge them in 15
> minutes, but could use the standard PFC chargers and Zillas for this
> system.
>
> Roland
>
>
> ----- Original Message -----
> From: <[email protected]>
> To: <[email protected]>
> Sent: Friday, November 16, 2007 8:46 AM
> Subject: [EVDL] UltraCapacitors
>
>
> > You may have seen this one already -
> >
> > http://www.spectrum.ieee.org/nov07/5636
> >
> > Here it is again -
> >
> > Best Regards -
> > Ed
> >
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
> 

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

Just a note, Victor said at the time that he thought he would make the
1/4 mile ok but didn't think he would be able to drive back and didn't
want to have to be towed.

Lawrence

-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of [email protected]
Sent: Friday, November 16, 2007 11:15 AM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] UltraCapacitors

Well so far the biggest I've seen on the market were the Maxwell
Ultracaps- a low voltage, high farad, very low resistance device which
is many orders of magnitude better than anything made previously.

A fellow here did this burnout entirely on a huge bank of them:
http://www.haritech.com/Woodburn2005058.MOV
http://www.haritech.com/VictorWoodburn_divx.avi

He didn't do a 1/4 mi run because despite the impressive initial kick it
would have petered out long before the finish line.

There have been greater caps like the ESMA:
http://www.esma-cap.com/Products/Capacitor_cells/EC353/?lang=English

ESMAs are almost as tricky as regular batts. They can't be discharged
below a certain voltage (like lead-acids) and may require electrolyte
topping off.

A company called EEStor announced with a LOT of fanfare that they would
be able to produce a barium-titanium-nitride cap with so much energy
density you could replace the primary batts (like in the IEEE Spectrum
article). In fact they spec'ed a cap like 200 or 300 lbs that contained
the drive shaft energy equivalent of about 4.5 gal of gasoline! 
However, I guess it's years later now and no product has been publicly
demonstrated that I know of, not even on a small scale.

Indeed caps would have a serious problem with broad input voltage
changes from "full" to the last 10% or 20%. EEStor also spec'ed their
cap as being thousands of volts! This is impossible for current
controllers, a special-purpose controller would be necessary. For
EEStor's spec, it would not dip below 100V or 200V until it was >>90%
drained so it wouldn't need a "boost" to be able to drive the motor. A
100V cap would be a different situation unless several were in series. 
Boost converters have their own difficulties at high power levels. Also
there's significant problems in designing a high power buck controller
to use thousands of volts to drive a DC motor at some 50V or 100V, these
high "buck ratios" come with their own technical difficulties which are
difficult and expensive to address.

Danny

----- Original Message -----
From: Roland Wiench <[email protected]>
Date: Friday, November 16, 2007 10:23 am
Subject: Re: [EVDL] UltraCapacitors
To: Electric Vehicle Discussion List <[email protected]>

> Hello ED,
> 
> I brought up the subject of SuperCapacitors, the first time I came 
> on this 
> list which could run a vehicle for a short distance that can be use 
> for 
> utility vehicles and buses that could run for about 10 to 15 miles.
> 
> The knee jerk reaction was that ultra capacitors would discharge 
> all there 
> energy in 15 seconds. I said these are super capacitors and have 
> electrolytes like a battery but can be recharge in 15 minutes.
> 
> So I contacted these companies, to see what size and how many I 
> need to run 
> my EV which I only use for very short trips which is not more than 
> 5 miles a 
> day. For my vehicles that weighs 7000 lbs with batteries, would 
> would weigh 
> 5500 lbs with super capacitors and have a range of 15 miles would 
> cost about 
> $40,000.00 which would be the last set of energy packs you will need.
> 
> I would not have to have a 300 amp charging station to charge them 
> in 15 
> minutes, but could use the standard PFC chargers and Zillas for 
> this system.
> 
> Roland
> 
> 
> ----- Original Message ----- 
> From: <[email protected]>
> To: <[email protected]>
> Sent: Friday, November 16, 2007 8:46 AM
> Subject: [EVDL] UltraCapacitors
> 
> 
> > You may have seen this one already -
> >
> > http://www.spectrum.ieee.org/nov07/5636
> >
> > Here it is again -
> >
> > Best Regards -
> > Ed
> >
> > _______________________________________________
> > For subscription options, see
> > http://lists.sjsu.edu/mailman/listinfo/ev
> > 
> 
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
> 

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev


_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

hey dan what type E V do you have ? motor ? controller ? finished weight ? are still being built ? 
----- Original Message ----- 
From: Dan Frederiksen<mailto:[email protected]> 
To: Electric Vehicle Discussion List<mailto:[email protected]> 
Sent: Friday, November 16, 2007 10:42 AM
Subject: Re: [EVDL] UltraCapacitors


Interesting but really sloppy that they compare capacity with an 
unspecified batterytechnology!
25% of a battery. what battery??
25% of lead and it's useless, 50% of the absolutely best lithiums and it 
could be quite interesting.

Dan



> [email protected]<mailto:[email protected]> wrote:
> > You may have seen this one already -
> >
> > http://www.spectrum.ieee.org/nov07/5636<http://www.spectrum.ieee.org/nov07/5636>
> ...


----------



## EVDL List (Jul 27, 2007)

I tried to get some info on the super caps that were built in Russia so I could compare them to batteries but never got a reply . Maxwell could replace lead batteries but the space was more than I wanted to allow AND THE COST!!!! it can be done but bring your checkbook !!! it was close to nimh batteries at that time 18 mo ago . I can out with the real world idea that the best use of ultra cps is for regen and acceleration 
----- Original Message ----- 
From: Gilbert, Brian D (GE Infra, Energy)<mailto:[email protected]> 
To: Electric Vehicle Discussion List<mailto:[email protected]> 
Sent: Friday, November 16, 2007 12:32 PM
Subject: Re: [EVDL] UltraCapacitors


Hi Roland,

What ultracapacitors were you looking at? A couple months ago I did a
comparison of Maxwell ultracaps (bcap3000) and the A123 batteries. The
Maxwells were 5.52 wh/kg and the A123s were 80-110 wh/kg depending on
discharge. I got the idea that at this point in time (with A123
batteries at least sort of available from Dewalt battery packs) that
ultracapacitors were not worth it. Are there ultracaps out there
significantly better than the Maxwells?

Thanks,
Brian 

-----Original Message-----
From: [email protected]<mailto:[email protected]> [mailto:[email protected]] On
Behalf Of Roland Wiench
Sent: Friday, November 16, 2007 8:22 AM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] UltraCapacitors

Hello ED,

I brought up the subject of SuperCapacitors, the first time I came on
this list which could run a vehicle for a short distance that can be use
for utility vehicles and buses that could run for about 10 to 15 miles.

The knee jerk reaction was that ultra capacitors would discharge all
there energy in 15 seconds. I said these are super capacitors and have
electrolytes like a battery but can be recharge in 15 minutes.

So I contacted these companies, to see what size and how many I need to
run my EV which I only use for very short trips which is not more than 5
miles a day. For my vehicles that weighs 7000 lbs with batteries, would
would weigh 5500 lbs with super capacitors and have a range of 15 miles
would cost about $40,000.00 which would be the last set of energy packs
you will need.

I would not have to have a 300 amp charging station to charge them in 15
minutes, but could use the standard PFC chargers and Zillas for this
system.

Roland


----- Original Message -----
From: <[email protected]<mailto:[email protected]>>
To: <[email protected]<mailto:[email protected]>>
Sent: Friday, November 16, 2007 8:46 AM
Subject: [EVDL] UltraCapacitors


> You may have seen this one already -
>
> http://www.spectrum.ieee.org/nov07/5636<http://www.spectrum.ieee.org/nov07/5636>
>
> Here it is again -
>
> Best Regards -
> Ed
>

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev<http://lists.sjsu.edu/mailman/listinfo/ev>
_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

BYU literally pushes their capacitor drag car (an old EV1) by hand to the line to save power.

----- Original Message ----
From: "Harris, Lawrence" <[email protected]>
To: Electric Vehicle Discussion List <[email protected]>
Sent: Friday, November 16, 2007 3:00:06 PM
Subject: Re: [EVDL] UltraCapacitors

Just a note, Victor said at the time that he thought he would make the
1/4 mile ok but didn't think he would be able to drive back and didn't
want to have to be towed.

Lawrence

-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of [email protected]
Sent: Friday, November 16, 2007 11:15 AM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] UltraCapacitors

Well so far the biggest I've seen on the market were the Maxwell
Ultracaps- a low voltage, high farad, very low resistance device which
is many orders of magnitude better than anything made previously.

A fellow here did this burnout entirely on a huge bank of them:
http://www.haritech.com/Woodburn2005058.MOV
http://www.haritech.com/VictorWoodburn_divx.avi

He didn't do a 1/4 mi run because despite the impressive initial kick it
would have petered out long before the finish line.

There have been greater caps like the ESMA:
http://www.esma-cap.com/Products/Capacitor_cells/EC353/?lang=English

ESMAs are almost as tricky as regular batts. They can't be discharged
below a certain voltage (like lead-acids) and may require electrolyte
topping off.

A company called EEStor announced with a LOT of fanfare that they would
be able to produce a barium-titanium-nitride cap with so much energy
density you could replace the primary batts (like in the IEEE Spectrum
article). In fact they spec'ed a cap like 200 or 300 lbs that contained
the drive shaft energy equivalent of about 4.5 gal of gasoline! 
However, I guess it's years later now and no product has been publicly
demonstrated that I know of, not even on a small scale.

Indeed caps would have a serious problem with broad input voltage
changes from "full" to the last 10% or 20%. EEStor also spec'ed their
cap as being thousands of volts! This is impossible for current
controllers, a special-purpose controller would be necessary. For
EEStor's spec, it would not dip below 100V or 200V until it was >>90%
drained so it wouldn't need a "boost" to be able to drive the motor. A
100V cap would be a different situation unless several were in series. 
Boost converters have their own difficulties at high power levels. Also
there's significant problems in designing a high power buck controller
to use thousands of volts to drive a DC motor at some 50V or 100V, these
high "buck ratios" come with their own technical difficulties which are
difficult and expensive to address.

Danny

----- Original Message -----
From: Roland Wiench <[email protected]>
Date: Friday, November 16, 2007 10:23 am
Subject: Re: [EVDL] UltraCapacitors
To: Electric Vehicle Discussion List <[email protected]>

> Hello ED,
> 
> I brought up the subject of SuperCapacitors, the first time I came 
> on this 
> list which could run a vehicle for a short distance that can be use 
> for 
> utility vehicles and buses that could run for about 10 to 15 miles.
> 
> The knee jerk reaction was that ultra capacitors would discharge 
> all there 
> energy in 15 seconds. I said these are super capacitors and have 
> electrolytes like a battery but can be recharge in 15 minutes.
> 
> So I contacted these companies, to see what size and how many I 
> need to run 
> my EV which I only use for very short trips which is not more than 
> 5 miles a 
> day. For my vehicles that weighs 7000 lbs with batteries, would 
> would weigh 
> 5500 lbs with super capacitors and have a range of 15 miles would 
> cost about 
> $40,000.00 which would be the last set of energy packs you will need.
> 
> I would not have to have a 300 amp charging station to charge them 
> in 15 
> minutes, but could use the standard PFC chargers and Zillas for 
> this system.
> 
> Roland
> 
> 
> ----- Original Message ----- 
> From: <[email protected]>
> To: <[email protected]>
> Sent: Friday, November 16, 2007 8:46 AM
> Subject: [EVDL] UltraCapacitors
> 
> 
> > You may have seen this one already -
> >
> > http://www.spectrum.ieee.org/nov07/5636
> >
> > Here it is again -
> >
> > Best Regards -
> > Ed
> >
> > _______________________________________________
> > For subscription options, see
> > http://lists.sjsu.edu/mailman/listinfo/ev
> > 
> 
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
> 

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev


_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev


____________________________________________________________________________________
Be a better sports nut! Let your teams follow you 
with Yahoo Mobile. Try it now. http://mobile.yahoo.com/sports;_ylt=At9_qDKvtAbMuh1G1SQtBI7ntAcJ

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

I looked at the capacitors on esma-cap.com and found the 30EC353
capacitor which they recommend for EVs. It has an energy density of 7.3
wh/kg, so a little better than the Maxwells. I like their voltage range
(48-24 volts) better than the Maxwells as well. I realize this
discussion started out with some yet-to-be-realized capacitor
technology, but here's the comparison I can make now:

Esma 30EC353
Energy Density 7.3 wh/kg
Power Density 434 w/kg
Cycle Life > 10000

A123Systems M1
Energy Density 76 wh/kg
Power Density 1510 w/kg
Cycle Life > 1000

The Esma info is from the site 
http://esma-cap.com/Products/Capacitor_modules/30EC353/?lang=English

The A123 info is from the data sheet. I used the 40 amp discharge curve
and estimated it was 2.65v for the bulk of the curve. If you use Bill
Dube's discharge rates, you'll get power densities close to 4000 w/kg.
I don't know what he's getting for energy density, or cycle life.

Regards,
Brian

-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of Roland Wiench
Sent: Friday, November 16, 2007 1:18 PM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] UltraCapacitors

Hello Brian,

These are SuperCapacitors, not UltraCapacitors. Assembly in cells like
a battery with a electrolyte. See the esma-cap.com site for the info.

Have not talk with these people since the last decade.

Roland


> Hi Roland,
>
> What ultracapacitors were you looking at? A couple months ago I did a
> comparison of Maxwell ultracaps (bcap3000) and the A123 batteries.
The
> Maxwells were 5.52 wh/kg and the A123s were 80-110 wh/kg depending on
> discharge. I got the idea that at this point in time (with A123
> batteries at least sort of available from Dewalt battery packs) that
> ultracapacitors were not worth it. Are there ultracaps out there
> significantly better than the Maxwells?
>
> Thanks,
> Brian
>
> -----Original Message-----
> From: [email protected] [mailto:[email protected]] On
> Behalf Of Roland Wiench
> Sent: Friday, November 16, 2007 8:22 AM
> To: Electric Vehicle Discussion List
> Subject: Re: [EVDL] UltraCapacitors
>
> Hello ED,
>
> I brought up the subject of SuperCapacitors, the first time I came on
> this list which could run a vehicle for a short distance that can be
use
> for utility vehicles and buses that could run for about 10 to 15
miles.
>
> The knee jerk reaction was that ultra capacitors would discharge all
> there energy in 15 seconds. I said these are super capacitors and
have
> electrolytes like a battery but can be recharge in 15 minutes.
>
> So I contacted these companies, to see what size and how many I need
to
> run my EV which I only use for very short trips which is not more than
5
> miles a day. For my vehicles that weighs 7000 lbs with batteries,
would
> would weigh 5500 lbs with super capacitors and have a range of 15
miles
> would cost about $40,000.00 which would be the last set of energy
packs
> you will need.
>
> I would not have to have a 300 amp charging station to charge them in
15
> minutes, but could use the standard PFC chargers and Zillas for this
> system.
>
> Roland
>
>
>
> > You may have seen this one already -
> >
> > http://www.spectrum.ieee.org/nov07/5636
> >
> > Here it is again -
> >
> > Best Regards -
> > Ed
> >

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

> On 16 Nov 2007 at 11:51, Jeff Major wrote:
> 
> > Ultracaps have worked very well in a parallel hybrid,
> > where the charge and discharge durations last from 7
> ...


----------



## EVDL List (Jul 27, 2007)

> [email protected] wrote:
> 
> > A fellow here did this burnout entirely on a huge bank of them:
> > http://www.haritech.com/Woodburn2005058.MOV
> ...


----------



## EVDL List (Jul 27, 2007)

Formula 1 rules have changed and regen will be allowed along with supplemental power sources. I think this is in 2008 with limited power output allowed, then higher outputs in subsequent years, I would be surprised if they didn't use u-caps! The next couple of years will be very interesting as they will push the limit.


----- Original Message ----
From: Jeff Major <[email protected]>
To: Electric Vehicle Discussion List <[email protected]>
Sent: Friday, November 16, 2007 2:51:14 PM
Subject: Re: [EVDL] UltraCapacitors



Hi Brian,

Maxwell are among the best Ultracaps available today. 
The paper that started this thread concerned the next
generation ultracap, using nanotube carbon, which
should increase the energy density 10 fold. Using
your numbers, that might explain the 50 percent vs
battery comparison mentioned.

Present technology ultracaps can compete with
batteries where you have a power application, instead
of an energy situation. I had a discussion on this
list with Bill Dube about 6 months ago on the subject.
If you can find that, you might find it interesting.

Ultracaps have worked very well in a parallel hybrid,
where the charge and discharge durations last from 7
to 20 seconds with power levels exceeding 150 kW. The
efficiency, temperature independence and cycle life
(1,000,000 plus) favor caps over batteries.

Regards,

Jeff M

--- "Gilbert, Brian D (GE Infra, Energy)"


> <[email protected]> wrote:
> 
> > Hi Roland,
> >
> ...


----------



## EVDL List (Jul 27, 2007)

Hi Victor,

Better check your math. Off by a factor of 10.

Regards,

Jeff M





> --- Victor Tikhonov <[email protected]> wrote:
> 
> > [email protected] wrote:
> >
> ...


----------



## EVDL List (Jul 27, 2007)

Hi David,

In my book, hybrid means more than one energy storage
system. So, fossil fuel and electric equals hybrid. 
Regardless of how you fuel the system.

And, yes, the parallel hybrid I referred to derives
all energy from the fossil fuel. No plug in. At this
stage, it make no since to plug in charge ultracaps
for the one megajoule it'd give you.

I consider that parallel hybrid a "true hybrid". But
with regards to a plug in hybrid benefiting from the
use of ultracapacitors, maybe. I could see a big
benefit for regenerative energy recovery if ultracaps
were used in conjunction with a battery.

Lots of possibilities.

Jeff M 





> --- David Roden <[email protected]> wrote:
> 
> > On 16 Nov 2007 at 11:51, Jeff Major wrote:
> >
> ...


----------



## EVDL List (Jul 27, 2007)

On 16 Nov 2007 at 20:15, Gilbert, Brian D (GE Infra, Energy) wrote:

> here's the comparison I can make now:
> 
> Esma 30EC353
> Energy Density 7.3 wh/kg
> Power Density 434 w/kg
> Cycle Life > 10000
> 
> A123Systems M1
> Energy Density 76 wh/kg
> Power Density 1510 w/kg
> Cycle Life > 1000

I would add :

US Battery US-145
Specific Energy 36 wh/kg @ 75a
Specific Power ?
Cycle life > 650

David Roden - Akron, Ohio, USA
EVDL Administrator

= = = = = = = = = = = = = = = = = = = = = = = = = = = = =
EVDL Information: http://www.evdl.org/help/
= = = = = = = = = = = = = = = = = = = = = = = = = = = = = 
Note: mail sent to "evpost" or "etpost" addresses will not 
reach me. To send a private message, please obtain my 
email address from the webpage http://www.evdl.org/help/ .
= = = = = = = = = = = = = = = = = = = = = = = = = = = = =


_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

Isn't the value of the Ultracap in their ability to discharge AND recharge
so quickly?

So in a hybrid if the ultracaps were used only for acceleration and were
re-charged first in regen they could extend the range significantly?

I have been playing with a hybrid design using stored hydraulic energy,
generated from braking, as energy for acceleration, but hydraulic systems
are so HEAVY lugging the weight around when not is use is counterproductive.
This design is used extensively is garbage trucks and other large short haul
trucks. 

Another newbie trying to put the pieces together.

EVPete (as opposed to the other new Pete)



-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf
Of Frank John
Sent: Saturday, November 17, 2007 4:47 AM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] UltraCapacitors

Formula 1 rules have changed and regen will be allowed along with
supplemental power sources. I think this is in 2008 with limited power
output allowed, then higher outputs in subsequent years, I would be
surprised if they didn't use u-caps! The next couple of years will be very
interesting as they will push the limit.


----- Original Message ----
From: Jeff Major <[email protected]>
To: Electric Vehicle Discussion List <[email protected]>
Sent: Friday, November 16, 2007 2:51:14 PM
Subject: Re: [EVDL] UltraCapacitors



Hi Brian,

Maxwell are among the best Ultracaps available today. 
The paper that started this thread concerned the next
generation ultracap, using nanotube carbon, which
should increase the energy density 10 fold. Using
your numbers, that might explain the 50 percent vs
battery comparison mentioned.

Present technology ultracaps can compete with
batteries where you have a power application, instead
of an energy situation. I had a discussion on this
list with Bill Dube about 6 months ago on the subject.
If you can find that, you might find it interesting.

Ultracaps have worked very well in a parallel hybrid,
where the charge and discharge durations last from 7
to 20 seconds with power levels exceeding 150 kW. The
efficiency, temperature independence and cycle life
(1,000,000 plus) favor caps over batteries.

Regards,

Jeff M

--- "Gilbert, Brian D (GE Infra, Energy)"


> <[email protected]> wrote:
> 
> > Hi Roland,
> >
> ...


----------



## EVDL List (Jul 27, 2007)

I wrote the author of the article Joel Schindall (that's what us trolls 
do) for a clarification on what energy densities they were actually 
expecting instead of just 25-50% of some unspecified battery. he answered:

Dear Dan,

Yes, it is hard to compare with battery technologies in a short article 
because the energy density varies quite a bit and they all have their 
relative advantages and disadvantages. I usually compare to Lithium 
Ion, most of which seem to be in the 120 to 180 Wh/kg range. I tend to 
favor the comparison with the 120 Wh/kg devices because they have more 
robust power density and more cycle life. We are estimating 30 to 60 
Wh/kg.

...Joel



Dan

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

Hi EVPete,

Comments inserted:



> --- Peter Oliver <[email protected]> wrote:
> 
> > Isn't the value of the Ultracap in their ability to
> > discharge AND recharge
> ...


----------



## EVDL List (Jul 27, 2007)

> > Ultracaps have worked very well in a parallel hybrid,
> > where the charge and discharge durations last from 7
> > to 20 seconds with power levels exceeding 150 kW.
>
> Wouldn't this apply only to a pseudo-hybrid - meaning the type where all the
> energy comes from fossil fuel? It seems to me that a true ("plug") hybrid
> wouldn't benefit from using ucaps rather than batteries. Am I missing
> something?

A plug-in hybrid could probably benefit from a mixture of batteries
and ultra-capacitors. The batteries store most of the energy and only
charge and discharge at 1C or 2C, and the ultra-capacitors store
enough energy to accelerate onto the freeway or regenerate quickly
down a hill, operating at extremely high max power rates.

-Morgan LaMoore

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

That's possible. Where exactly did you spot 10x error?

Victor




> Jeff Major wrote:
> > Hi Victor,
> >
> > Better check your math. Off by a factor of 10.
> ...


----------



## EVDL List (Jul 27, 2007)

> Do the math: my 16.8F cap has 1.18^7 J of energy stored. 1MJ=0.3kWh
> stored, so 11.8 MJ in my bank contained 3.54kWh of energy.
E = 1/2 * C * V^2, V=375V, so E = 1.18MJ. not 11.8MJ.
You might have made it down to the end of the track at full acceleration, 
but it would have been tight.
Regards,
Chris Brune

> My power consumption is 180 Wh/mile (@ ~45MPH), so my theoretical range
> (if I can extract all the energy while decaying voltage) is
> precisely 3540/180=19.6 miles - far more than the track length.
> If I discharge to the half of the voltage (~187V) my energy left
> would be 2.96MJ or 0.88 kWh. That means I realistically had
> 3.54-0.88-2.652kWh or 2652/180=14.7 miles range and at 187V the drive
> system still works OK with some room to go still.
>
> --
> Victor
> '91 ACRX - something different
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev 

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

I don't know anything about "the math" but I was at
Woodburn and saw both the burn out and the trip down
the 1/4 mi and return to the pits on only capacitors
so some one doesn't have either the right information
or the right "math" or is this another time when the
math and the reality do not jive





> --- Chris Brune <[email protected]> wrote:
> 
> > > Do the math: my 16.8F cap has 1.18^7 J of energy
> > stored. 1MJ=0.3kWh
> ...


----------



## EVDL List (Jul 27, 2007)

That's interesting Keith...you saw BOTH a burnout and a trip down the
track....hmmm...Victor did an ultracap burnout (and there's video of it),
but even HE has never acknowledged doing a run down the track after. Maybe
he forgot that he raced down the track on ultracaps after?

I think I missed that year's Woodburn races.

-Myles Twete, Portland, Or.

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf
Of keith vansickle
Sent: Sunday, November 18, 2007 11:05 AM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] UltraCapacitors

I don't know anything about "the math" but I was at
Woodburn and saw both the burn out and the trip down
the 1/4 mi and return to the pits on only capacitors
so some one doesn't have either the right information
or the right "math" or is this another time when the
math and the reality do not jive





> --- Chris Brune <[email protected]> wrote:
> 
> > > Do the math: my 16.8F cap has 1.18^7 J of energy
> > stored. 1MJ=0.3kWh
> ...


----------



## EVDL List (Jul 27, 2007)

How is it that 1.18^7 (which I read as "one point one eight times
ten to the seventh power" and not "one point one eight to the seventh
power") Joules is anything other than:
11,800,000 Joules or 11.8 MegaJoules?



> Chris Brune <[email protected]> wrote:
> > > Do the math: my 16.8F cap has 1.18^7 J of energy stored. 1MJ=0.3kWh
> > > stored, so 11.8 MJ in my bank contained 3.54kWh of energy.
> > E = 1/2 * C * V^2, V=375V, so E = 1.18MJ. not 11.8MJ.
> ...


----------



## EVDL List (Jul 27, 2007)

> Chris Brune <[email protected]> wrote:
> > > Do the math: my 16.8F cap has 1.18^7 J of energy stored. 1MJ=0.3kWh
> > > stored, so 11.8 MJ in my bank contained 3.54kWh of energy.
> > E = 1/2 * C * V^2, V=375V, so E = 1.18MJ. not 11.8MJ.
> ...


----------



## EVDL List (Jul 27, 2007)

> Andrew Kane <[email protected]> wrote:
> > How is it that 1.18^7 (which I read as "one point one eight times
> > ten to the seventh power" and not "one point one eight to the seventh
> > power") Joules is anything other than:
> ...


----------



## EVDL List (Jul 27, 2007)

Yes, you're right - my typo in the online calc I used to
enter the numbers and come up with an answer. I looked
at the capacitance field "F" while typing amount of
microfarades to see 11.8 number in it, but didn't notice
"x10" in front of it already, thus the error: the
calc took 11.8F from the box and multiplied by 10 which
is 10 times more capacitance than I really have.

The calculator:
http://hyperphysics.phy-astr.gsu.edu/hbase/electric/capeng.html

1.18MJ is just 354Wh, and with 180 Wh/mile consumption the
range is only 2 miles (more believable). Could make it to the
end of the track (with some spare) for fun, but not at full acceleration.

Thanks for the correction Chris!

Victor




> Chris Brune wrote:
> >> Do the math: my 16.8F cap has 1.18^7 J of energy stored. 1MJ=0.3kWh
> >> stored, so 11.8 MJ in my bank contained 3.54kWh of energy.
> > E = 1/2 * C * V^2, V=375V, so E = 1.18MJ. not 11.8MJ.
> ...


----------



## EVDL List (Jul 27, 2007)

Myles, I made an error typing in numbers in online calc
and it gave me misleading answer - GIGO, you know.

My energy storage was enough for 2 miles range (and
voltage by the end would be zero, so I couldn't even
use all of it), but I could attempt the run down the track
at slow speed (+ to and from the pits) just to demonstrate
this is doable, but I didn't bother to estimate storage
before and haven't tested such thing. So, no you didn't miss
another Woodburn, I never ran down the track on the caps alone,
just did burnout (which actually doesn't require that much
energy and I could keep burning longer for spectator's
excitement, but the car started creeping forward too far
because hand brake didn't hold well, so I has to stop).

I might re-fit ACRX with this caps bank again, it's
still sitting in my garage unused.

Victor




> Myles Twete wrote:
> > That's interesting Keith...you saw BOTH a burnout and a trip down the
> > track....hmmm...Victor did an ultracap burnout (and there's video of it),
> > but even HE has never acknowledged doing a run down the track after. Maybe
> ...


----------



## EVDL List (Jul 27, 2007)

with 1.18MJ depending on car weight I figure you could reach maybe 
160km/h before the energy was gone then coast any remaining time over 
the line.
no energy for burnout. maybe a 13second run? assuming the rest of the 
car is up to the power level.

you'd need more caps to take full advantage of the capacitor advantage 
and beat the battery cars but worth a shot I'd say

Dan

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

> Dan Frederiksen <[email protected]> wrote:
> > with 1.18MJ depending on car weight I figure you could reach maybe
> > 160km/h before the energy was gone then coast any remaining time over
> > the line.
> ...


----------



## EVDL List (Jul 27, 2007)

Victor, out of curiosity, do you know how much that bank weighs??



----- Original Message ----
From: Victor Tikhonov <[email protected]>
To: Electric Vehicle Discussion List <[email protected]>
Sent: Sunday, November 18, 2007 4:40:29 PM
Subject: Re: [EVDL] UltraCapacitors


<My energy storage was enough for 2 miles range (and
voltage by the end would be zero...
I might re-fit ACRX with this caps bank again, it's
still sitting in my garage unused.>






____________________________________________________________________________________
Be a better sports nut! Let your teams follow you 
with Yahoo Mobile. Try it now. http://mobile.yahoo.com/sports;_ylt=At9_qDKvtAbMuh1G1SQtBI7ntAcJ

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

I did deduct a bit but you're probably right. I don't know how it 
handles the voltage drop.
I didn't include energy for the return which I consider irrelevant BUT 
the car might have regenerative braking in which case it might have 
enough for that as well

I'd say it's still worth a shot. If not for a sprint why would you use 
supercaps in it in the first place...

Dan


Morgan LaMoore wrote:
>


> Dan Frederiksen <[email protected]> wrote:
> >
> >> with 1.18MJ depending on car weight I figure you could reach maybe
> >> 160km/h before the energy was gone then coast any remaining time over
> ...


----------



## EVDL List (Jul 27, 2007)

One PC2500 cap (2,700F 2.5V) is 725g, I'd estimate 0.8kg with
braided strap lugs and bolts.

I have 160 of them in series, so 116kg (255 lb) total.
That is excluding aluminum box they are in. You can guess the weight
of the box based on the photos, I'd say ~20kg (~50 lb) may be.
Links to a few photos of my installation are near bottom
of this page: http://www.metricmind.com/ac_honda/ultracaps.htm

Also, you may find this interesting read about ultracaps usage
in an EV:

http://www.itee.uq.edu.au/~walkerg/publications/2002/ultracaps_in_EVs_02.pdf

--
Victor
'91 ACRX - something different




> Frank John wrote:
> > Victor, out of curiosity, do you know how much that bank weighs??
> >
> >
> ...


----------



## EVDL List (Jul 27, 2007)

OK I was wrong. He just made a burn out It was 2 or 3
years ago so I just remembered wrong which sometimes
happens
Keith


> --- Victor Tikhonov <[email protected]> wrote:
> 
> > Myles, I made an error typing in numbers in online
> > calc
> ...


----------



## EVDL List (Jul 27, 2007)

Good stuff; I've been following some of the installations in buses in California and delivery trucks, etc.

Victor, in your application did you ever run batteries and ucaps in parallel? I've tried to understand how this might work in the past (using Maxwell's design tools) and w/o separate controllers I concluded that the batteries had lower internal resistance and would probably do more work than the caps. I'd appreciate any thoughts you may have had along this line.





----- Original Message ----
From: Victor Tikhonov <[email protected]>
To: Electric Vehicle Discussion List <[email protected]>
Sent: Monday, November 19, 2007 1:53:47 AM
Subject: Re: [EVDL] UltraCapacitors


One PC2500 cap (2,700F 2.5V) is 725g, I'd estimate 0.8kg with
braided strap lugs and bolts.

I have 160 of them in series, so 116kg (255 lb) total.
That is excluding aluminum box they are in. You can guess the weight
of the box based on the photos, I'd say ~20kg (~50 lb) may be.
Links to a few photos of my installation are near bottom
of this page: http://www.metricmind.com/ac_honda/ultracaps.htm

Also, you may find this interesting read about ultracaps usage
in an EV:

http://www.itee.uq.edu.au/~walkerg/publications/2002/ultracaps_in_EVs_02.pdf

--
Victor
'91 ACRX - something different




> Frank John wrote:
> > Victor, out of curiosity, do you know how much that bank weighs??
> >
> >
> ...


----------



## EVDL List (Jul 27, 2007)

Hi Frank,

It depends on the specific battery and ultracap in
question, but generally, ultracaps have lower ESR.

Regards,

Jeff M





> --- Frank John <[email protected]> wrote:
> 
> > Good stuff; I've been following some of the
> > installations in buses in California and delivery
> ...


----------



## EVDL List (Jul 27, 2007)

yeah for anything but a pure bred drag racer with controller and motor 
able to take the power there is no real advantage in current supercaps. 
I think the best power density is 12kW/kg assuming the interconnections 
are thick enough to carry it which I'm not sure they are in victor's, 
and A123 is around 3kW/kg if I recall correctly so it would be hard to 
beat the power of 160kg caps even with A123s. and it's not my impression 
that his lithiums are high power ones.

Dan



> Frank John wrote:
> > Good stuff; I've been following some of the installations in buses in California and delivery trucks, etc.
> >
> > Victor, in your application did you ever run batteries and ucaps in parallel? I've tried to understand how this might work in the past (using Maxwell's design tools) and w/o separate controllers I concluded that the batteries had lower internal resistance and would probably do more work than the caps. I'd appreciate any thoughts you may have had along this line
> ...


----------



## EVDL List (Jul 27, 2007)

[No message]


----------



## EVDL List (Jul 27, 2007)

let's take the largest cap maxwell has, 3000F 2.7V with specific energy 
of 5.52Wh/kg and 13800W/kg specific power.
200kg of that is almost 4MJ of energy and 2.76MW of power (not far from 
1.21jiggawatts  certainly enough power so the issue would be energy.

let's say a 1000kg car and 25% loss in the initial acceleration, that's 
77.5m/s or 279km/h before it will have to coast the rest of the way and 
lose some more speed to the wind etc. that in itself is faster than the 
top speed of the white zombie I believe and even more than your last run 
Dube isn't it. and there is significant advantage in gaining the speed 
quickly even if you never reach higher. the power is certainly high 
enough so it's just a matter of motor and wheels to take advantage of 
the power.
if you want more you could increase the capacitor mass to 300kg or even 
more.

while the capacitors have an energy limit uncomfortably close to just 
enough, I believe you are wrong in dismissing them for drag.
you may have to use funny wheels and all wheel drive but the power seems 
to be there to leave batteries in the dust.

Dan




> Bill Dube wrote:
> > It has been discussed to death in the past, but the bottom line is
> > that ultra caps are a poor choice for drag racing. At first glance,
> > by the uninitiated, they may seem like a good fit, but when you
> ...


----------



## EVDL List (Jul 27, 2007)

[No message]


----------



## EVDL List (Jul 27, 2007)

I expected that thought but I was still hoping it would not be made 
without also acknowledging it can be done with relative ease. white 
zombie as it is already has a trick to adapt voltage wise, shifting the 
two motors from parallel to serial during the run. you could take that 
further.
when a cap is at half voltage it has already given up 75% of its energy. 
so imagine a 350v system still providing 175v when 75% discharged.
it's an irrelevant technical detail to the argument.

Dan




> Mark Eidson wrote:
> > It is hard to get all of the energy stored out of a capacitor. A
> > battery's voltage drops ~20% while giving up its energy. A
> > capacitor's voltage drops 100% giving up its energy. You have to have
> ...


----------



## EVDL List (Jul 27, 2007)

Look in the archives. I proved quite conclusively that Ultra caps are 
unsuitable for drag racing.

There are two issues that folks don't take into account. One is that 
you get only a fraction of the energy if you draw full power. The big 
thing that folks don't quite get is that you need the max power at 
the END of the run, not the beginning. As you discharge the cap, the 
voltage drops. The power available is the square of the voltage. 
Thus, when you need power on the strip, you can't get it from the caps.

Here we go again for those too lazy to simply search the archives, 
even just a few months back. From 5/16/2007:

>>>I went to the Ness website and browsed the ultra capacitors to see 
>>>where the current specs were these days.
>>>Under very gentle discharge, ultra caps have a specific energy in 
>>>the range of 2 to 5 Watt-hours/kg. (This will be much lower under 
>>>high discharge. You won't get even half of that at max power.) 
>>>Here are a few comparisons:
>>>AGM lead-acid ~ 30 W-hr/kg
>>>NiCads ~ 45 W-hr/kg
>>>Li-Ion FePo ~ 110 W-hr/kg
>>>Now you are getting a glimpse at the problem. (This is why the 
>>>folks using caps pushed the car to the starting line, by the way.)
>>>It takes at least 500 Watt-hours to get the KillaCycle to make a 
>>>fast run down the strip. This is about how much energy it takes to 
>>>get a 619 lb bike with a 135 lb driver to cover the 1/4 mile in 
>>>the 8's. This does not include the burn out, the trip to the 
>>>starting line, or the trip back to the pits. This weight assumes 
>>>your ultra caps weigh just 161 lbs.
>>>If you use the least-powerful ultra caps that have the most energy 
>>>per kg, and you (incorrectly) assume that you will be able to 
>>>extract the total maximum specific energy from them, the pack will 
>>>weigh a minimum
>>>of 100 kg = 220 lbs. This is about 60 lbs heavier than the present 
>>>pack. Oops! The bike goes much slower because it weighs more AND 
>>>is has much less available HP. Let's fix the HP problem.
>>>If you were to select capacitors that are more powerful, (on par 
>>>with A123 cells) the specific energy would drop to 2 (or less.) 
>>>This boosts the cap pack weight to 500/2 = 250 kg = 550 lbs! Oops! 
>>>The bike goes even slower, not faster.
>>>As we discussed in a previous note, you can't get all the 
>>>available energy out of a pack of caps at the drag strip because 
>>>the drag racing discharge curve is "upside down" from what the 
>>>caps are able to deliver. You need about _twice_ the weight in 
>>>caps to deliver some sort of HP at least half-way down the track. 
>>>This pushes the pack weight up even more!
>>>As the pack weight grows, this boosts the vehicle weight, which 
>>>boosts the HP and energy requirements in proportion. It is a 
>>>losing proposition. It just won't work.
>>>Ultra caps are not the best choice for drag racing. This is 
>>>obvious if you just do a few simple calculations. You don't even 
>>>need to do the more detailed calculations because the numbers are 
>>>so bad, even making wildly optimistic assumptions.
>>> Bill Dube'

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

only proved in your own mind Bill. the 200kg pack for the 1000kg total 
car could by their own specs deliver a max of 2.78MW of power. max power 
is when the resistance outside is the same as inside so a 50% loss of 
energy at max power. that would mean only 2MJ remaining if you needed 
all 3700HP but of course you probably don't. so at much lower power 
levels you get much higher efficiency which voids your argument that the 
caps somehow can't give up their energy if you push them. their 
willingness to give up their energy is indeed their very strength. 
13800W/kg so you are flat out wrong. vs around 2500W/kg for A123.
the fact that it drops in voltage as it is drained is not a problem 
either, as you would have understood had you not been afraid to read 
what I wrote.
let's say you run dry only 60% down the track, that's actually quite 
good because that means you have very quickly spent the 4MJ and achieved 
your max speed early and that translates to a quick time provided it's 
not aerodynamically horrible (you can apply the power to optimise time 
according to drag profile). you erroneously conclude that because it 
will be low on power in the last part it will lose but your mistake is 
you overlook that the speed has been built up much faster and thus the 
first part has been traversed in a shorter time. meaning ahead. think 
about it

their only weakness is their specific energy which is just on the edge 
of what you would like in order to take advantage of them but by your 
own numbers of 500Wh to push the killacycle down the track that's very 
close to the amount of energy an 80 kg pack like yours would hold. you 
just have to get used to the idea that you will have to coast the last 
part at which point you are way ahead. my hunch tells me you can even 
increase the pack size a bit for an even better compromise since the 
power is certainly there to push the additional weight. if 80kg can push 
300kg well I figure 120kg can push 340kg better.

from your archive reference it seems like you are comparing with a cap 
that's inferior to the maxwell one I am refering to. please take the 
time to observe its specs. 5.52Wh/kg and 13800W/kg. since it's teetering 
on the edge of required energy, any significantly poorer energy density 
would make your conclusion correct.
similarly any future significant improvements over the one I'm citing 
would make the capacitor even more relevant for the quarter mile. just 
10Wh/kg would facilitate times in the 5s I believe. that's top fuel 
domain if I am not mistaken.

Dan




> Bill Dube wrote:
> > Look in the archives. I proved quite conclusively that Ultra caps are
> > unsuitable for drag racing.
> >
> ...


----------



## EVDL List (Jul 27, 2007)

[No message]


----------



## EVDL List (Jul 27, 2007)

>
>their only weakness is their specific energy which is just on the edge
>of what you would like in order to take advantage of them but by your
>own numbers of 500Wh to push the killacycle down the track that's very
>close to the amount of energy an 80 kg pack like yours would hold.

Old pack holds 7.6 kW-hrs. Present pack holds 9.1 kW-hrs. We have 
made back-to-back runs going FASTER on the second run, setting a 
record at the time. In theory, we could make more than a dozen runs, 
including the burnouts and the round trip to the pits, without recharging.

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

> Dan Frederiksen <[email protected]> wrote:
> > the fact that it drops in voltage as it is drained is not a problem
> > either, as you would have understood had you not been afraid to read
> > what I wrote.
> ...


----------



## EVDL List (Jul 27, 2007)

Those caps may have quite low resistance.
However, when put in parallel with a pack, there's a problem.

Say you have a 144V pack that sags to 110V under heavy acceleration and
the caps are directly in parallel and you pull that heavy acceleration.
The caps are great at t=0, but the cap voltage decays as they provide
current. As cap voltage drops the current will shift back to the batt.
Eventually- time depends on capacitance- all the current is coming from
the batt, batt's sagging to 110V, and the caps do nothing. In fact the
batt voltage will stay low for an equally long period as the batt puts
out equally high currents to raise the cap voltage on these
low-impedance caps. 

Furthermore, at 110V the cap still has 58% of its initial energy, it's
just not usable. It might be desirable if your car can keep moving at
say 70V to disconnect the batt and just run on the caps since they don't
wear out or suffer ill effects from high current charge/discharge. But
that is quite an extra level of complexity. In fact once you separate
them you and let cap voltage drop below batt voltage they can't just be
reconnected, it's almost like a short circuit on the batt and the batt
will see the highest currents possible which isn't improving the lifespan.

Don't forget such a cap bank is, today at least, 1) phenomenally
expensive, 2) very large, 3) very heavy. So adding something similar in
size in addition to the main battery bank to stiffen it isn't currently
reasonable and practical. 

Furthermore, the "ultracaps" technology (ESMA or Maxwell) does not
scale. So if they're still made of 2.7V Maxwell caps you need 56 for a
150V pack (plus safety margin), and Maxwell can't increase that voltage.
If you want to experiment with a pack 1/10th the size to stiffen the
batt (replace your controller's input cap) you can't make it work with
1/10th the caps, that's only 16.2V! And you still need a method of
charge balancing for 56 caps. Furthermore, even if Maxwell made caps
1/10th the capacitance and 1/10th the weight and size to fit your plan,
they'd likely be 10x the internal resistance which may compromise your
stiffening plan. Nor is there any guarantee that Maxwell making a
smaller cap would result in a proportionally smaller price, the machines
may only be able to produce at the same speed for either size.

Danny

----- Original Message -----
From: Frank John <[email protected]>
Date: Monday, November 19, 2007 7:29 am
Subject: Re: [EVDL] UltraCapacitors
To: Electric Vehicle Discussion List <[email protected]>

> Good stuff; I've been following some of the installations in buses 
> in California and delivery trucks, etc.
> 
> Victor, in your application did you ever run batteries and ucaps in 
> parallel? I've tried to understand how this might work in the past 
> (using Maxwell's design tools) and w/o separate controllers I 
> concluded that the batteries had lower internal resistance and 
> would probably do more work than the caps. I'd appreciate any 
> thoughts you may have had along this line.
> 
> 
> 
> 
> 
> ----- Original Message ----
> From: Victor Tikhonov <[email protected]>
> To: Electric Vehicle Discussion List <[email protected]>
> Sent: Monday, November 19, 2007 1:53:47 AM
> Subject: Re: [EVDL] UltraCapacitors
> 
> 
> One PC2500 cap (2,700F 2.5V) is 725g, I'd estimate 0.8kg with
> braided strap lugs and bolts.
> 
> I have 160 of them in series, so 116kg (255 lb) total.
> That is excluding aluminum box they are in. You can guess the weight
> of the box based on the photos, I'd say ~20kg (~50 lb) may be.
> Links to a few photos of my installation are near bottom
> of this page: http://www.metricmind.com/ac_honda/ultracaps.htm
> 
> Also, you may find this interesting read about ultracaps usage
> in an EV:
> 
>
http://www.itee.uq.edu.au/~walkerg/publications/2002/ultracaps_in_EVs_02.pdf
> 
> --
> Victor
> '91 ACRX - something different
> 
> 


> > Frank John wrote:
> > > Victor, out of curiosity, do you know how much that bank weighs??
> > >
> > >
> ...


----------



## EVDL List (Jul 27, 2007)

Gosh Dan, I'm glad you know more about getting down the track than Bill
does. You should read his post again though. Here is the critical
information.

Capacitors lose power as they are discharged. (Your 200kg capacitor
bank will not have 2.76MW of power after it has discharged some.)

Here is some more information, again from Bill. Too bad he doesn't know
anything about doing 6.8s in the 1/4 mile (oops, sorry, that's 402.3m).
A123 cells, on Killacycle, are putting out 175A at close to 1.7V, or
almost 300W. That's over 4kW/kg. They will do that during the entire
run.

You mentioned Top Fuel. They claim to have about 6MW of power (also
available the entire run) and a mass of 1009kg.

Note that they can't use all that power at the start of their run
because 1. they have to maintain traction, and 2. they can't make their
driver pass out.

So when your capacitors have their maximum power, you can't use it, and
you won't have it later when you need it down the track.

BYU has already done this. They used 88kg of Maxwell ultracaps in a
614kg EV1. Their time for the 402.3m was 15.774s at 34.63m/s (77.47m/h
for those not SI units obsessed).

http://www.maxwell.com/pdf/uc/white-papers/UC_power_for_drag_racecar.pdf

If you still think that 200kg of capacitors will get a 1000kg racecar
into the 5s range, you should give us some more of your math so that we
can sort this out.

Regards,
Brian

-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of Dan Frederiksen
Sent: Monday, November 19, 2007 12:44 PM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] UltraCapacitors

only proved in your own mind Bill. the 200kg pack for the 1000kg total
car could by their own specs deliver a max of 2.78MW of power. max power
is when the resistance outside is the same as inside so a 50% loss of
energy at max power. that would mean only 2MJ remaining if you needed
all 3700HP but of course you probably don't. so at much lower power
levels you get much higher efficiency which voids your argument that the
caps somehow can't give up their energy if you push them. their
willingness to give up their energy is indeed their very strength. 
13800W/kg so you are flat out wrong. vs around 2500W/kg for A123.
the fact that it drops in voltage as it is drained is not a problem
either, as you would have understood had you not been afraid to read
what I wrote.
let's say you run dry only 60% down the track, that's actually quite
good because that means you have very quickly spent the 4MJ and achieved
your max speed early and that translates to a quick time provided it's
not aerodynamically horrible (you can apply the power to optimise time
according to drag profile). you erroneously conclude that because it
will be low on power in the last part it will lose but your mistake is
you overlook that the speed has been built up much faster and thus the
first part has been traversed in a shorter time. meaning ahead. think
about it

their only weakness is their specific energy which is just on the edge
of what you would like in order to take advantage of them but by your
own numbers of 500Wh to push the killacycle down the track that's very
close to the amount of energy an 80 kg pack like yours would hold. you
just have to get used to the idea that you will have to coast the last
part at which point you are way ahead. my hunch tells me you can even
increase the pack size a bit for an even better compromise since the
power is certainly there to push the additional weight. if 80kg can push
300kg well I figure 120kg can push 340kg better.

from your archive reference it seems like you are comparing with a cap
that's inferior to the maxwell one I am refering to. please take the
time to observe its specs. 5.52Wh/kg and 13800W/kg. since it's teetering
on the edge of required energy, any significantly poorer energy density
would make your conclusion correct.
similarly any future significant improvements over the one I'm citing
would make the capacitor even more relevant for the quarter mile. just
10Wh/kg would facilitate times in the 5s I believe. that's top fuel
domain if I am not mistaken.

Dan




> Bill Dube wrote:
> > Look in the archives. I proved quite conclusively that Ultra caps are
> > unsuitable for drag racing.
> >
> ...


----------



## EVDL List (Jul 27, 2007)

> Bill Dube wrote:
> > Build the car and prove me wrong.
> >
> I was hoping you might be able to understand theoretical considerations
> ...


----------



## EVDL List (Jul 27, 2007)

BYU has done 14.08 seconds with that car. The capacitor banks took up alot more space than the killacycle's battery pack would -- you'd have trouble cramming as many kW of power in with capacitors due to volume restrictions.

https://orca.byu.edu/content/Stories/featurebaxter.html

----- Original Message ----
From: "Gilbert, Brian D (GE Infra, Energy)" <[email protected]>
To: Electric Vehicle Discussion List <[email protected]>
Sent: Monday, November 19, 2007 3:18:18 PM
Subject: Re: [EVDL] UltraCapacitors

... BYU ... used 88 kg of Maxwell ultracaps in a 614 kg EV1. Their time for the 402.3m was 15.774s at 34.63m/s (77.47m/h ...). ...





____________________________________________________________________________________
Never miss a thing. Make Yahoo your home page. 
http://www.yahoo.com/r/hs

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

> Say you have a 144V pack that sags to 110V under heavy acceleration and
> the caps are directly in parallel and you pull that heavy acceleration.
> The caps are great at t=0, but the cap voltage decays as they provide
> current. As cap voltage drops the current will shift back to the batt.
> Eventually- time depends on capacitance- all the current is coming from
> the batt, batt's sagging to 110V, and the caps do nothing. In fact the
> batt voltage will stay low for an equally long period as the batt puts
> out equally high currents to raise the cap voltage on these
> low-impedance caps.

Yeah, I know how the capacitance voltage drop works and how it's only
useful for short bursts. You size the capacitors to last as long as
the peak load (about 7 seconds for accelerating onto the freeway). If
you use lots of power for longer than that, the load shifts back to
the batteries and the caps do nothing. For those step loads, though,
it goes through its useful capacity (the top 42% or less) quickly
while demand lasts then is recharged by the batteries at the rate
determined by the batteries' ESR. Because the voltage doesn't fall as
low with the ultra-caps as it would without them, the peak current
from the battery is lower, even though it delivers the same total
energy.

Yes, it would be crazy heavy and expensive, probably too much to be
worth it. I'd say a 60s2p set with max 162V, 100F would be nice;
starting at 144V, it could deliver 485 amps for 7 seconds before
reaching 100V; plenty of juice to accelerate onto the freeway. It
weighs 66 kg and costs an insanely huge amount of money, though.

However, in the branch from this thread started by Dan, I ran some
calculations for ultra-caps vs A123. A123 won by quite a bit because
the A123 only had 3 times more ESR while having a huge capacity
advantage. A dragster on ultra-caps gets 7.6 seconds in my sim while
one with A123's gets 7.11 seconds in the simulation.

Based on this, I give up on ultra-capacitors (unless/until they get at
least an order of magnitude more energy density).

However, how about this idea: stiffen a flooded lead-acid pack with
A123's. It doesn't have the voltage drop problem that the ultra-cap
does; the biggest design problem is matching the nominal and max
voltages of the A123 and flooded packs. (Also, the stiffening would
only work really well in the middle 80% of the A123's SOC.)

I'm hoping to buy the rest of my components and build my motorcycle
(with PbA) by next summer. If I can get some A123's for a decent
price, I'll try it out and let you all know.

Good luck and happy EV-ing!

-Morgan LaMoore

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

They worked only in parallel and precisely because R_int of crappy
TS cells I had was too high. The caps eliminated otherwise huge
voltage sag and also took regen nicely. Without hem during regen
voltage shoots up esp. in cold weather (R_int of TS cells
is much higher in cold).

S, no caps did most the work. Out of 110A on hard acceleration,
70A was coming out of caps and 40A out of battery. After that
battery [relatively] slowly charged caps back to its voltage.

Victor



> Frank John wrote:
> > Good stuff; I've been following some of the installations in buses in
> > California and delivery trucks, etc.
> >
> ...


----------



## EVDL List (Jul 27, 2007)

[No message]


----------



## EVDL List (Jul 27, 2007)

> Dave Davidson <[email protected]> wrote:
> > ... or using a controller that can suck more amps from a lower voltage pack and transform it into more voltage to the motor (AC controllers do this, but I'm not aware of a DC controller that does. Doesn't mean it couldn't be done, though.) ...
> 
> Really? Do you know of any specific 3-phase controller topologies that
> ...


----------



## EVDL List (Jul 27, 2007)

I don't want to look stupid, but I can't pass the moment where I could add something useful... so here goes...

What whould happen if you broke your packs into halfsize units, then during the second half of the run, you switched from parrallel to series for half the pack (or some other mix). Wouldn't that give you the voltage hike you need? 

It may take a custom controller and/or fast switching to a second controller. But even relays should be faster than any mechanical shifter ever was. 

IT's not lost on me that some over-amp or shorting issues must be delt with. But that seems better then using a DC-DC hike converter. Even using a second full controller would be comparable in weight and more efficient than up-side voltage converters.




Arak Leatham - Web and Desktop Systems Developer




Estimating, Point of Sale, Tracking, Reporting Applications> Date: Tue, 20 Nov 2007 21:31:47 -0600> From: [email protected]> To: [email protected]> Subject: Re: [EVDL] UltraCapacitors> >


> Dave Davidson <[email protected]> wrote:> > ... or using a controller that can suck more amps from a lower voltage pack and transform it into more voltage to the motor (AC controllers do this, but I'm not aware of a DC controller that does. Doesn't mean it couldn't be done, though.) ...> > Really? Do you know of any specific 3-phase controller topologies that> boost voltage? All of the AC controller designs I've looked at just> use a standard 3-phase inverter that can only reduce the voltage, not> increase it.> > I guess a current-fed controller could probably do it, but affordable> controllers are voltage-based, not current-based. (Current-fed> controllers use big, expensive, huge inductors on the input and output> so it has almost constant current in and almost!
> constant current out.> They also need switches that can handle a lot more voltage because of> the voltage spikes from the inductors.)> > I'm currently designing a DC controller based on the buck-boost> converter that can take in a low input voltage and output a high motor> voltage. It's a low-power controller, though, designed to control a> mini-bike at 2 kW or lower. I'm making it so that we can make a> minibike that uses only 12V or 24V battery voltage but uses a higher> voltage motor.> > The thing is, it will cost more than a "standard" controller; it needs> higher-rated parts to get the same output voltage and current. For> car-sized controllers, that's a really, really bad idea price-wise,> and for smaller controllers, it just costs more.> > -Morgan LaMoore> > _______________________________________________> For subscription options, see> http://lists.sjsu.edu/mailman/listinfo/ev
> _________________________________________________________________
> Share life as it happens with the new Windows Live.Download today it's FREE!
> ...


----------



## EVDL List (Jul 27, 2007)

You get the same effect by using two motors. Start in series, then switch to parallel so each motor goes from seeing half the pack voltage to the entire pack voltage. Believe John Wayland pioneered this, quite effectively.

> From: [email protected]> To: [email protected]> Date: Tue, 20 Nov 2007 20:47:55 -0700> Subject: Re: [EVDL] UltraCapacitors> > > I don't want to look stupid, but I can't pass the moment where I could add something useful... so here goes...> > What whould happen if you broke your packs into halfsize units, then during the second half of the run, you switched from parrallel to series for half the pack (or some other mix). Wouldn't that give you the voltage hike you need? > > It may take a custom controller and/or fast switching to a second controller. But even relays should be faster than any mechanical shifter ever was. > > IT's not lost on me that some over-amp or shorting issues must be delt with. But that seems better then using a DC-DC hike converter. Even using a second full controller would be comparable in weight and more efficient than up-side voltage converters.> > > > > Arak Leatham - Web and Desktop Systems Developer> > 
_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

> Dave Davidson wrote:
> >> ... or using a controller that can suck more amps from a lower
> >> voltage pack and transform it into more voltage to the motor (AC
> >> controllers do this, but I'm not aware of a DC controller that does.
> ...


----------



## EVDL List (Jul 27, 2007)

The system used in Toyota's Hybrids (HSD) is such a system. They boost the 
DC from the batteries to almost double at around 500V, then create 3-phase 
AC using 3 T-bridge sections. The raising of the voltage means less 
amperage in the inverter, which means lower counts of transistors, and 
smaller motor windings.

The technology exists to do this from a widely varying voltage input, but it 
would require a beefy boost converter, and it would mean significant added 
complexity and expense. In addition, There is no "off the shelf" product I 
know of that will do this.

-Phil
----- Original Message ----- 
From: "Morgan LaMoore" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Tuesday, November 20, 2007 7:31 PM
Subject: Re: [EVDL] UltraCapacitors


>


> Dave Davidson <[email protected]> wrote:
> >> ... or using a controller that can suck more amps from a lower voltage
> >> pack and transform it into more voltage to the motor (AC controllers do
> >> this, but I'm not aware of a DC controller that does. Doesn't mean it
> ...


----------



## EVDL List (Jul 27, 2007)

Thanks for the great info, Lee!

> Yes; all of the ones used for EVs boost voltage when operating in regen m=
ode. They use the motor's winding inductance as the boost inductor, and the=
3-phase bridge which just happens to be configured as a boost converter (s=
ame as the DC controller mentioned above).

Oops, I mis-worded my question. I meant to ask if there were any that
boosted the voltage in motoring mode. By putting an inductor between
the DC bus and each leg of the inverter, though, each leg could
independently boost the voltage.

> > I'm currently designing a DC controller based on the buck-boost
> > converter that can take in a low input voltage and output a high
> > motor voltage.
>
> Look at the Cuk' converter. It can be built with the same parts as a regu=
lar buck converter (1 transistor, 1 diode, 1 capacitor, 1 inductor) but its=
output voltage can be higher or lower than the input voltage (though it wi=
ll be of opposite polarity). The Cuk' also has the interesting capability o=
f reducing the input *and* output ripple current to almost zero.

According to the websites I looked at, the =C6uk converter needs 2
inductors, one on the input and one on the output. With those
inductors, you're definitely right about the ripple current! I don't
know what sort of capacitor I'd use to transfer the charge, though; it
would have to be pretty good.

My original configuration was a buck-boost converter using only 1
transistor, 1 diode, and 1 inductor (letting the motor's inertia act
as a "capacitor"). About as simple as you can get while still being a
switch-mode power supply.

> Maybe. If your goal is to make the cheapest possible controller that bare=
ly lives out the warranty, it will look like a Curtis; dozens of dirt-cheap=
200v MOSFETs, electrolytics, and diodes.
>
> But 600v IGBTs and diodes don't cost much more than 200v ones. Film capac=
itors are far more reliable than electrolytics. The controller will cost mo=
re initially, but last 10 times longer.

Wow, those film capacitors look great! I had never looked at them
before! They have amazingly low ESR! They're really expensive, though,
over 5 times more than electrolytics for the same ripple current
rating. But with their stated lifetime, it's probably worth it!

-Morgan LaMoore

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

And this is also what a lot of contact controller do,
I believe. But not to compensate for the batteries
changing voltage, but to change the voltage delivered
from the battery pack to the motor.

Yes, it would work, but keep in mind how many switches
you would need (mechanical or solid state). Each one
needs to handle a lot of current and high voltage (I'm
not willing to guess how high, but higher than the max
of each bank being switched around). At some point it
becomes impractical, depending on the number of banks
that get switched around.

Steven Ciciora



> --- Dave Davidson <[email protected]> wrote:
> 
> > You get the same effect by using two motors. Start
> > in series, then switch to parallel so each motor
> ...


----------



## EVDL List (Jul 27, 2007)

> Dave Davidson wrote:
> >> ... or using a controller that can suck more amps from a lower
> >> voltage pack and transform it into more voltage to the motor...
> 
> ...


----------



## EVDL List (Jul 27, 2007)

>Really? Do you know of any specific 3-phase controller topologies that
>boost voltage? All of the AC controller designs I've looked at just
>use a standard 3-phase inverter that can only reduce the voltage, not
>increase it.

Huh? Do you mean that a Controller/Inverter can't take a 120V, 500A 
'feed' from the batteries, and convert it into a 240V, 250A feed to 
the motor, or am I reading that wrong? 

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

> Dominant <[email protected]> wrote:
> > Huh? Do you mean that a Controller/Inverter can't take a 120V, 500A
> > 'feed' from the batteries, and convert it into a 240V, 250A feed to
> > the motor, or am I reading that wrong?
> ...


----------



## EVDL List (Jul 27, 2007)

> Lee Hart <[email protected]> wrote:
> 
> Dear Lee,
> We have a S10EV that needs a hands on technician. We live in the Doyles=
> ...


----------



## EVDL List (Jul 27, 2007)

> [email protected] wrote:
> > Dear Lee, We have a S10EV that needs a hands on technician. We live
> > in the Doylestown,PA area (north of Philadelphia) 215-669-9426. Can
> > you help us find somebody?
> ...


----------



## EVDL List (Jul 27, 2007)

>Arak Leatham said
>What whould happen if you broke your packs into halfsize units, then during
>the second half of the run, you switched from parrallel to series for half the
>pack (or some other mix). Wouldn't that give you the voltage hike you need? 

you could go further in this direction and use some number of batteries that can
divide lots of ways, like 720 batteries (720 being 6 factorial) which can be
split into:
720s1p
360s2p
240s3p
180s4p
144s5p
120s6p
90s8p
80s9p
72s10p
60s12p
40s18p
36s20p
30s24p
and all the opposites.

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

I don't think that one needs to make it so fine and complicated. The =

energy in the capacitor goes down in the square of the voltage. When =

one is down to 1/2th of full voltage, one has only 1/4th of the energy =

left.

What about a following system:

You have a controller capable of handling, say 150-300 volts of input. =

You divide the capacitor pack in 4 parts and so have connection =

possibilities: 1S4P, 2S2P, 4S1P. Capacitors are charged to 300V in 1S4P =

and you use the pack down to 150V. Now change to 2S2P configuration and =

you go again down to 150V. Then 4S1P and again from 300V to 150V.

If my reasoning is correct, you have come down to 1/16 of the original =

capacitance and 1/2 of the original voltage. So you have 1/64 of the =

original energy left and 63/64 used for traction.

1,6% of the energy left unusable, 98,4% used for traction. Not too bad =

for quite a simpe configoration.

Seppo

>----Alkuper=E4inen viesti----
>L=E4hett=E4j=E4: [email protected]
>P=E4iv=E4m=E4=E4r=E4: 29.11.2007 23:38
>Vastaanottaja: <[email protected]>
>Aihe: Re: [EVDL] UltraCapacitors
>
>>Arak Leatham said
>>What whould happen if you broke your packs into halfsize units, then =

during
>>the second half of the run, you switched from parrallel to series =

for half the
>>pack (or some other mix). Wouldn't that give you the voltage hike =

you need? =

> =

>you could go further in this direction and use some number of =

batteries that can
>divide lots of ways, like 720 batteries (720 being 6 factorial) which =

can be
>split into:
>720s1p
>360s2p
>240s3p
>180s4p
>144s5p
>120s6p
>90s8p
>80s9p
>72s10p
>60s12p
>40s18p
>36s20p
>30s24p
>and all the opposites.
>
>_______________________________________________
>For subscription options, see
>http://lists.sjsu.edu/mailman/listinfo/ev
>



_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

> Seppo Lindborg wrote:
> > I don't think that one needs to make it so fine and complicated. The
> > energy in the capacitor goes down in the square of the voltage
> 
> ...


----------



## EVDL List (Jul 27, 2007)

*[EVDL] Ultracapacitors*

Saw on a recent discussion about the NASA report for "The Fuel Cell Powered Club Car Carryall" about the exploration of using ultracapacitors instead of batteries (a combination of the two rather than full on batteries). 

This isn't a new technology, but rather a new application of the tech... is anybody with any engineering background currently exploring this? If we could reduce the amount of batts a car has to carry... 

Thanks,

Matt
Independence, MO



_______________________________________________
For general EVDL support, see http://evdl.org/help/
For subscription options, see http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

*Re: [EVDL] Ultracapacitors*

Some time ago, I contacted ESMA(Russia) about there super capacitors, that 
are use in running street buses and trolley buses that may run off grid for 
awhile. They have to carry a lot of super capacitors to run off grid for 
about 7 miles.

To give you a example of what it will take to use 3600F super capacitors in 
my 7000 lb ev, ESMA sent me a spread sheet that it would take 600 of these 
20 amp cells at 3 volts each for a 180 volts at 200 amps that will give me 
only 10 mile range for $40,000.00.

I can buy 200 years of lead acid batteries for that. I'm on my fourth pack 
for 37 years with a EV range up to 50 miles.

Seattle is now running some type of on-off grid buses now, but I do not know 
if its batteries or capacitors.

Roland


----- Original Message ----- 
From: "Matt Searcy" <[email protected]>
To: <[email protected]>
Sent: Monday, July 21, 2008 8:17 AM
Subject: [EVDL] Ultracapacitors


> Saw on a recent discussion about the NASA report for "The Fuel Cell 
> Powered Club Car Carryall" about the exploration of using ultracapacitors 
> instead of batteries (a combination of the two rather than full on 
> batteries).
>
> This isn't a new technology, but rather a new application of the tech... 
> is anybody with any engineering background currently exploring this? If we 
> could reduce the amount of batts a car has to carry...
>
> Thanks,
>
> Matt
> Independence, MO
>
>
>
> _______________________________________________
> For general EVDL support, see http://evdl.org/help/
> For subscription options, see http://lists.sjsu.edu/mailman/listinfo/ev
>
> 


_______________________________________________
For general EVDL support, see http://evdl.org/help/
For subscription options, see http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

*Re: [EVDL] Ultracapacitors*

I like the idea of ultra-caps, but for the same or better cost, size,
and weight, can't one use some high quality 10C+ LiFeP04 packs?

In essence, the ultra-caps are dead weight and only add power, not
energy. The Lithium pack can do both.

A 30Ah 144V pack from LifeBatt would cost ~$9000 USD w/ BMS, but could
output ~400A for 18 seconds (in addition to your regular pack current)
and add up to 14 miles of range at 300Wh/mi.

Agree, or am I missing something here?
Brian




> Matt Searcy <[email protected]> wrote:
> > Saw on a recent discussion about the NASA report for "The Fuel Cell Powered Club Car Carryall" about the exploration of using ultracapacitors instead of batteries (a combination of the two rather than full on batteries).
> >
> > This isn't a new technology, but rather a new application of the tech... is anybody with any engineering background currently exploring this? If we could reduce the amount of batts a car has to carry...
> ...


----------



## EVDL List (Jul 27, 2007)

*Re: [EVDL] Ultracapacitors*

There's the sustainability question.
If they last longer than you don't have to keep buying batteries.



> Brian Pikkula <[email protected]> wrote:
> 
> > I like the idea of ultra-caps, but for the same or better cost, size,
> > and weight, can't one use some high quality 10C+ LiFeP04 packs?
> ...


----------



## EVDL List (Jul 27, 2007)

*Re: [EVDL] Ultracapacitors*

The idea is that the ultracapacitors can increase the available peak 
power. Can we believe that you can actually draw on the LiFePO4 
batteries at a 10C rate without significant sag? The ultracaps could 
reduce sag at peak demand.

There is another NASA/Glenn (Lewis Research Center at the time) 
report from 1999 on the Hybrid Electric Transit Bus (HETB) project 
that discusses 
using ultracapacitors. 
<http://gltrs.grc.nasa.gov/reports/1999/TM-1999-208890.pdf> The 
advantages claimed are better acceleration and ease of recapturing 
energy using regenerative braking.

--Glen Hoag
[email protected]

At 12:26 PM 7/21/2008, you wrote:
>There's the sustainability question.
>If they last longer than you don't have to keep buying batteries.
>
>


> Brian Pikkula <[email protected]> wrote:
> >
> > > I like the idea of ultra-caps, but for the same or better cost, size,
> > > and weight, can't one use some high quality 10C+ LiFeP04 packs?
> ...


----------



## EVDL List (Jul 27, 2007)

*Re: [EVDL] Ultracapacitors*

Matt,

I'm currently looking into this approach not so that I can use less 
batteries, but so that I can use high energy batteries without having 
to spend a premium on high power batteries. It seams the LiFePO4 
batteries are typically either designed for for storing a lot of 
energy, but delivering that energy at a low power, or they are 
designed for high power output, with a compromise of storing less 
specific energy. High power is needed in an EV for acceleration, and 
climbing hills. High Energy is needed for range. Also, high energy 
and high power seam to come at a premium in the lithium battery 
market. Going with the less expensive high energy cells and coupling 
them with suitably sized capacitors to provide instantaneous power 
when you need it is a sound technological idea. The question is does 
it make economic sense.

If its economically attractive it may work for some, but not for 
others. It would be great for stop and go and short hills. However, 
it would not work for those that need sustained power to climb 
mountains and such.

Roger



> Matt Searcy wrote:
> 
> > Saw on a recent discussion about the NASA report for "The Fuel Cell
> > Powered Club Car Carryall" about the exploration of using
> ...


----------



## EVDL List (Jul 27, 2007)

*Re: [EVDL] Ultracapacitors*

Maxwell has a 63F 125v Cap Module
-- 750A peak (1 sec), with 55A cont and 150A cont with cooling (forced air)
130.9lbs.

http://www.maxwell.com/ultracapacitors/products/modules/bmod0063-125v.asp
bmod0063-125v 
http://www.maxwell.com/pdf/uc/datasheets/20080707_mc_power_series_125_1011161_rev3.pdf
Maxwell 125v UltraCap Spec Sheet 

No idea on cost.

I plan to run some spice simulations at some point soon to "play with this
concept"

Mike




Roger Heuckeroth wrote:
> 
> Matt,
> 
> I'm currently looking into this approach not so that I can use less 
> batteries, but so that I can use high energy batteries without having 
> to spend a premium on high power batteries. It seams the LiFePO4 
> batteries are typically either designed for for storing a lot of 
> energy, but delivering that energy at a low power, or they are 
> designed for high power output, with a compromise of storing less 
> specific energy. High power is needed in an EV for acceleration, and 
> climbing hills. High Energy is needed for range. Also, high energy 
> and high power seam to come at a premium in the lithium battery 
> market. Going with the less expensive high energy cells and coupling 
> them with suitably sized capacitors to provide instantaneous power 
> when you need it is a sound technological idea. The question is does 
> it make economic sense.
> 
> If its economically attractive it may work for some, but not for 
> others. It would be great for stop and go and short hills. However, 
> it would not work for those that need sustained power to climb 
> mountains and such.
> 
> Roger
> 
>


> Matt Searcy wrote:
> >
> >> Saw on a recent discussion about the NASA report for "The Fuel Cell
> >> Powered Club Car Carryall" about the exploration of using
> ...


----------



## EVDL List (Jul 27, 2007)

*Re: [EVDL] Ultracapacitors*

One of the reasons EVers are interesting in SuperCaps is for capturingthe
energy of regenerative braking.

In theory mode, the output of the braking is much more than can be dumped
into the batteries without frying them. ie hundreds of Amps.... So, a
SuperCap
is supposed to be able to take ALL that energy and store it for awhile and
then send it off to the motor controller or batteries at a rate that wont
cause a fire.

Flywheels are supposed to do this also, but are very massive.

Now, how long can the SuperCap hold that charge?
I dont think it can hold it for a day of driving, but maybe enuf to get from
one trolley to the next.





> Matt Searcy <[email protected]> wrote:
> 
> > Saw on a recent discussion about the NASA report for "The Fuel Cell Powered
> > Club Car Carryall" about the exploration of using ultracapacitors instead of
> ...


----------



## EVDL List (Jul 27, 2007)

*Re: [EVDL] Ultracapacitors*

ultracapcitors are already patented as of july th of this year. the patent
number is 7400490. it requires a lab and such to think of making it. but it
is in patent to let everyone know




> Roland Wiench wrote:
> >
> > Some time ago, I contacted ESMA(Russia) about there super capacitors, that
> > are use in running street buses and trolley buses that may run off grid
> ...


----------



## EVDL List (Jul 27, 2007)

*Re: [EVDL] Ultracapacitors*

When you run the simulations... I figure what you want to start with 
is a high battery pack voltage feeding the cap pack. Caps have a 
linear voltage drop as you pull current from them, So, say the top 
voltage the motor can use is 170 V per Jim Husted. So, the energy 
that the cap could provide on a pulse basis is the energy stored 
between 170 and 300 V.

So, in your case you want to use that energy climbing hills in 
Austin. So, the total energy available would be dissipated in say a 
1-2 minute hill climb, or a 10-15 second acceleration from a stop. To 
that energy you should add the continuous energy available from the 
battery pack. Figured at 2C or so. You should be able to work 
backwards to find out the capacitor size you need.




> txhokie4life wrote:
> 
> >
> >
> ...


----------



## EVDL List (Jul 27, 2007)

*Re: [EVDL] Ultracapacitors*

but the ones i found can me added and added to get what we need i think since
is not wire based or other things to cause and issue. i don't know tried to
read and got lost lol from all the technical info



> Glen Hoag wrote:
> >
> > The electric double layer capacitor (EDLC) or ultracapacitor has been
> > around for quite a number of years, originally in small values. I
> ...


----------



## EVDL List (Jul 27, 2007)

*Re: [EVDL] Ultracapacitors*

What do you use to model the batteries in Spice?

Chris Holland
iPhone email



> txhokie4life <[email protected]> wrote:
> 
> >
> >
> ...


----------



## EVDL List (Jul 27, 2007)

*[EVDL] ultracapacitors*

52 3000 farad maxwell 2.7 volt boostcap capacitors all in series..

do they have enough energy to launch a 5000 pound vehicle?
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.sjsu.edu/mailman/private/ev/attachments/20110204/e456e0a5/attachment.html 
_______________________________________________
| REPLYING: address your message to [email protected] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

*Re: [EVDL] ultracapacitors*

Electrical Energy:
E=0.5CV^2 but in reality you want E=0.5C(V1^2-V2^2) since you can't
use the full voltage range.

Kinetic energy:
E = 0.5mass*velocity^2

Solve for velocity for first order estimate. In reality it will be
worse since you have losses and the voltage of the caps decline as you
accelerate and the voltage of the motor increases.



On Fri, Feb 4, 2011 at 10:40 AM, Michael Clark


> <[email protected]> wrote:
> > 52 3000 farad maxwell 2.7 volt boostcap capacitors all in series..
> >
> > do they have enough energy to launch a 5000 pound vehicle?
> ...


----------



## EVDL List (Jul 27, 2007)

*Re: [EVDL] ultracapacitors*

um Equation required: Energy = 0.5 * C * V^2

Energy = .5 x 3000 x 140.4^2

29568240 joules.

Now how to translate 5000 lb vehicle launch into something useful... I'm not
sure what you mean by launch..

Smarter people please come help

-Cole




> Michael Clark <[email protected]>wrote:
> 
> > 52 3000 farad maxwell 2.7 volt boostcap capacitors all in series..
> >
> ...


----------



## EVDL List (Jul 27, 2007)

*Re: [EVDL] ultracapacitors*

F= 3000/52



> Cole <[email protected]> wrote:
> > um Equation required: Energy = 0.5 * C * V^2
> >
> > Energy = .5 x 3000 x 140.4^2
> ...


----------



## EVDL List (Jul 27, 2007)

*Re: [EVDL] ultracapacitors*

yes launch is not as in launch into the air lol... launch from a dead stop
to 55 mph..

i posted this question earlier and got 54 capacitors as an answer, but
nothing more than that.

Ive found out 52 in series isnt a good idea.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.sjsu.edu/mailman/private/ev/attachments/20110205/d1cd3363/attachment.html 
_______________________________________________
| REPLYING: address your message to [email protected] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

*Re: [EVDL] ultracapacitors*

The energy to launch (accelerate) a 5000 pound car
(I expect that is a truck) will cost almost as much
as driving it a mile down the road at constant speed
(which means that everytime you use the friction
brakes to stop from full speed and accelerate again,
you lose almost 1 mile range !!!!)

The easiest way to calculate is in Metric, you see
the Kinetic energy as:
(55 MPH = 24.6 meter/s)
E = 0.5 * 2250(kg) * 24.6(m/s)squared
= 679806J
Let's call that 680 kiloJoule = 680 kWs = 0.188kWh

To see the usable energy in 52 series capacitors we
need to determine how much voltage drop you can take,
say you take them from their max 140V to 70V so you
can use 3/4 of the energy in the caps, then the
usable energy in the caps is:

E = 0.5 * C * 3/4 * V^2
The capacitance is 3000/52 since there are 52 in
series, so the capacitance is divided by the nr in
series, C = 58

E = 0.5 * 58 * 3/4 * 170^2 = 426300 Joule

Say (optimistically) that there is 20% loss when
transferring energy from the caps to the wheels, so
0.8 * 426kJ = 341kJ
This is half the energy you need to reach 55 MPH
so either you need twice the size of cap (run them
buddy-paired or in two strings) or accept that you
will reach only 70% of your target speed (=39MPH)

Note that a lighter car will also need much less power
to accelerate, but the real killer is the speed which
is in the equation squared, so twice the speed means
four times as much energy...

Hope this helps,

Cor van de Water
Director HW & Systems Architecture Group
Proxim Wireless Corporation http://www.proxim.com
Email: [email protected] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [email protected]
Tel: +1 408 383 7626 VoIP: +31 20 3987567 FWD# 25925
Tel: +91 (040)23117400 x203 XoIP: +31877841130

-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of Peter Gabrielsson
Sent: Saturday, February 05, 2011 12:33 AM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] ultracapacitors

Electrical Energy:
E=0.5CV^2 but in reality you want E=0.5C(V1^2-V2^2) since you can't use
the full voltage range.

Kinetic energy:
E = 0.5mass*velocity^2

Solve for velocity for first order estimate. In reality it will be worse
since you have losses and the voltage of the caps decline as you
accelerate and the voltage of the motor increases.



On Fri, Feb 4, 2011 at 10:40 AM, Michael Clark


> <[email protected]> wrote:
> > 52 3000 farad maxwell 2.7 volt boostcap capacitors all in series..
> >
> > do they have enough energy to launch a 5000 pound vehicle?
> ...


----------

