# [EVDL] Tavrima capacitors



## EVDL List (Jul 27, 2007)

Hello Adrian,

The ESCap 90/300 which is a 300 v at 75kw runs at about $2400.00. When 
running in parallel with the battery pack, the caps will reduce the battery 
sag during high ampere discharge.

If you fill out the there form stating all the specifications of your EV, 
they could custom build a cap for what you want to do. Email your EV work 
to them and they may even put in there one of there ad.

Roland




----- Original Message ----- 
From: "Adrian DeLeon" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Tuesday, May 12, 2009 6:15 PM
Subject: [EVDL] Tavrima capacitors


> Roland,
>
> Just checked out the Tavrimas, very cool! Did you get an estimate on
> price? I was thinking about replacing the 48V block in the rear of my
> Cabriolet with lithiums if the price drops a bit (what's the lithium
> equivalent of a T-105, 100AHr?). But if the price is right, replacing the
> 3 batteries under the rear seat with a large capacitor might be a better
> option. It's definitely hard to beat the $/mile of lead acid, especially
> if you don't drive many miles per year.
>
> -Adrian
>
> > next battery pack change. Instead of 260 AH battery pack at 180 volts,
> > I am going to 252 volt pack, using one of the U.S. Battery deep cycle
> > packs at
> > 150 AH using one of Tavrima supercapacitors and still be about 600 lbs
> > lighter.
>
> _______________________________________________
> General EVDL support: http://evdl.org/help/
> Usage guidelines: http://evdl.org/help/index.html#conv
> Archives: http://evdl.org/archive/
> Subscription options: http://lists.sjsu.edu/mailman/listinfo/ev
>
> 

_______________________________________________
General EVDL support: http://evdl.org/help/
Usage guidelines: http://evdl.org/help/index.html#conv
Archives: http://evdl.org/archive/
Subscription options: http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

Roland, can you give us some numbers for the pack you plan to match up
with the capacitor?

Thanks

Dave Cover



> Roland Wiench <[email protected]> wrote:
> > Hello Adrian,
> >
> > The ESCap 90/300 which is a 300 v at 75kw runs at about $2400.00. W=
> ...


----------



## EVDL List (Jul 27, 2007)

Hello Dave,

The battery choices are either 30 each US-145 XC for 180 V pack at 251 AH at 
154 mins @ 75 amps which would weigh 2160 lbs and have a range of 61 miles. 
There would be no room for the supercapacitor.

The next battery choice is 30 each US-8VGCHC XC for 240 V pack at 183 AH at 
95 mins @ 75 amps which would weigh 2070 lbs and have a range of 58 miles. 
There would be no room for the supercapacitor.

The next battery choice is 23 each US-8VGCHC XC for 184 V pack at 183 AH at 
95 mins @ 75 amps which would weigh 1587 lbs and have a range of 51 miles. 
There would be no room for the supercapacitor.

The next battery choice is 21 each US-12V XC for 252 V pack at 155 AH at 77 
mins @ 75 amps which would weigh 1795.5 lbs and have a range of 62.5 miles. 
There would be no room for the supercapacitor.

The next battery choice is 18 each US-12V XC for 216 V pack at 155 AH at 77 
mins @ 75 amps and would weigh 1611 lbs and have a range of 53.5 miles. 
There is now room for a supercapacitor.

The last battery choice is 18 each US-EV 145 XC for 216 V pack at 145 AH at 
72 mins @ 75 amps and would weigh 1546 lbs and have a range of 51.3 miles. 
There is now room for a supercapacitor.

All these U.S. Batteries come with the large L battery post. Can not get 
these types with a Trojan battery.

Note: These range estimates are consider at a constant 75 battery amps and 
not allowing for the increase battery ampere for stop and acceleration back 
up to speed. The supercapacitor will keep the batteries at a more constant 
battery ampere, while the capacitor will discharge the higher ampere during 
the acceleration.

The batteries choices that use with the supercapacitor should improve in 
range and life of the battery.

If the supercapacitor is connected in parallel with the battery pack and you 
only use one volt and amp indication, you will not be able to tell what the 
status of the battery and the capacitor is doing.

What I plan to do is to connected the negative side of the capacitor 
directly to the negative side of the battery pack. The positive side of the 
capacitor will be fuse with a 400 amp Buss Limitron fuse that can take a 
short time surge well over 2000 amps.

The fuse is than connected to a 600 amp contactor that is also rated for 
2000 amp surge. A amp meter shunt is then connected to the output of the 
contactor and then is connected ahead of the E-meter shunt, so now the 
E-meter now only reads the battery voltage and ampere and the capacitor 
reads a separate voltage and ampere.

When the ignition switch is turn to the ignition ON position, it then turns 
on a small 12 volt isolated relay that then turns on the contactor for the 
supercapacitor.

There will be a 1 pole 3 position selector switch in the 12 volt control 
line to this capacitor contactor. It will be use to turn on the contactor 
to connect the capacitor in parallel with the batteries during charging.

You also want the capacitor to be disconnected from the batteries when doing 
maintenance on any one of the battery links. You do not want to cause a 
high sparking discharge. Also you do not want the capacitor in the same 
compartment as the batteries. I plan to put in a seal off compartment for 
this device.

Roland




----- Original Message ----- 
From: "dave cover" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Wednesday, May 13, 2009 5:06 AM
Subject: Re: [EVDL] Tavrima capacitors


Roland, can you give us some numbers for the pack you plan to match up
with the capacitor?

Thanks

Dave Cover



> Roland Wiench <[email protected]> wrote:
> > Hello Adrian,
> >
> > The ESCap 90/300 which is a 300 v at 75kw runs at about $2400.00. When
> ...


----------



## EVDL List (Jul 27, 2007)

Roland

I'm asking so I can understand how all this works. Now, it looks like
you are only considering the capacitor with a 216 volt pack. Is this
only due to physical limitations? Space available?

I thought I'd read about people using two different chemistry packs
together, one with high amp hours and low discharge rate and another
with low amphours but high discharge. As the high AH pack sags during
heavy acceleration the other helps out. The voltage of the helper pack
is usually a little lower than the main pack. And I thought the same
general theory applied to capacitors.

So my question is, how does a 300v capacitor with a 216 volt pack? How
do you calculate the correct capacitor for a given pack size?

Thanks

Dave Cover



> Roland Wiench <[email protected]> wrote:
> > Hello Dave,
> >
> > The battery choices are either 30 each US-145 XC for 180 V pack at 251 AH=
> ...


----------



## EVDL List (Jul 27, 2007)

Hello Dave,

A capacitor that is rated at 300 volts is the maximum volt rating of the 
capacitor. The 216 volt battery when charge at a equalization charge is 
280.08 volts. So that is still below the capacitor rating.

If you charge a 12 volt battery to 15 volts, then this type of capacitor in 
parallel will be also charge at 15 volts.

Yes, the size of that battery or any other type that has the same cubic 
space, will allow for me in install seal fiberglass compartment in the 
battery box to contain the capacitor plus the other components and room for 
a BMS system and battery monitor units.

Roland


----- Original Message ----- 
From: "dave cover" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Wednesday, May 13, 2009 7:51 AM
Subject: Re: [EVDL] Tavrima capacitors


Roland

I'm asking so I can understand how all this works. Now, it looks like
you are only considering the capacitor with a 216 volt pack. Is this
only due to physical limitations? Space available?

I thought I'd read about people using two different chemistry packs
together, one with high amp hours and low discharge rate and another
with low amphours but high discharge. As the high AH pack sags during
heavy acceleration the other helps out. The voltage of the helper pack
is usually a little lower than the main pack. And I thought the same
general theory applied to capacitors.

So my question is, how does a 300v capacitor with a 216 volt pack? How
do you calculate the correct capacitor for a given pack size?

Thanks

Dave Cover



> Roland Wiench <[email protected]> wrote:
> > Hello Dave,
> >
> > The battery choices are either 30 each US-145 XC for 180 V pack at 251 AH
> ...


----------



## EVDL List (Jul 27, 2007)

How does one calculate the size of a super cap in farads needed to go 1/4 
mile and supply 2000 amps at 240v for say 20 seconds?

Dave Delman
eLectricDeLorean.com**************Dell Mini Netbooks: Great deals starting 
at $299 after instant savings! 
(http://pr.atwola.com/promoclk/100126575x1221972443x1201442012/aol?redir=http:%2F%2Fad.doubleclick.net%2Fclk%3B214819441%3
B36680237%3Bi)

_______________________________________________
General EVDL support: http://evdl.org/help/
Usage guidelines: http://evdl.org/help/index.html#conv
Archives: http://evdl.org/archive/
Subscription options: http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

Dave

Sets your sights a little higher, go for 12 seconds ;^)

(and then push it back up the track)




> <[email protected]> wrote:
> > How does one calculate the size of a super cap in farads needed to go 1/4
> > mile and supply 2000 amps at 240v for say 20 seconds?
> >
> ...


----------



## EVDL List (Jul 27, 2007)

Is 240v the start voltage or the end voltage?
A capacitor sags proportionally to how much charge has been drawn from it.

Say if you are using a zilla 2k.
Start voltage 360v
End voltage 240v.
2000A continuous
20 seconds run time

Capacitance (F) = current*time/voltage change
= 2000*20/120
= 333F with a max cap voltage of 360v.
For a cap (bank?) this large, you are looking at 2900kg (6400lbs)

Matt 

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf
Of [email protected]
Sent: Thursday, 14 May 2009 12:35 AM
To: [email protected]
Subject: Re: [EVDL] Tavrima capacitors

How does one calculate the size of a super cap in farads needed to go 1/4
mile and supply 2000 amps at 240v for say 20 seconds?

Dave Delman
eLectricDeLorean.com**************Dell Mini Netbooks: Great deals starting
at $299 after instant savings! 
(http://pr.atwola.com/promoclk/100126575x1221972443x1201442012/aol?redir=htt
p:%2F%2Fad.doubleclick.net%2Fclk%3B214819441%3
B36680237%3Bi)

_______________________________________________
General EVDL support: http://evdl.org/help/ Usage guidelines:
http://evdl.org/help/index.html#conv
Archives: http://evdl.org/archive/
Subscription options: http://lists.sjsu.edu/mailman/listinfo/ev



--
Internal Virus Database is out-of-date.
Checked by AVG. 
Version: 7.5.557 / Virus Database: 270.12.11 - Release Date: 30/04/2009
12:00 AM




-- 
Internal Virus Database is out-of-date.
Checked by AVG. 
Version: 7.5.557 / Virus Database: 270.12.11 - Release Date: 30/04/2009 12:00 AM

_______________________________________________
General EVDL support: http://evdl.org/help/
Usage guidelines: http://evdl.org/help/index.html#conv
Archives: http://evdl.org/archive/
Subscription options: http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

Can I keep my existing 156V AGM pack and install a SuperCap in series with 
my pack (with appropriate charging and switching contactors) to double the 
pack voltage (initally) and keep the current the same?

Start V 156

End V 0

Current 2000A

Time 20 seconds

2000 * 20 / 150 = 266 F @ 200 Volts Hmm can't seem to find that on the 
DigiKey site.

Thank you,

Dave Delman
1981 Electric DeLorean Project
electricdelorean.com
http://evalbum.com/1482 


In a message dated 5/13/2009 2:09:04 P.M. Eastern Standard Time, 
[email protected] writes:

Message: 10
Date: Thu, 14 May 2009 01:15:37 +0800
From: "Matt Lacey" <[email protected]>
Subject: Re: [EVDL] Tavrima capacitors
To: "'Electric Vehicle Discussion List'" <[email protected]>
Message-ID: <[email protected]>
Content-Type: text/plain; charset=us-ascii

Is 240v the start voltage or the end voltage?
A capacitor sags proportionally to how much charge has been drawn from it.

Say if you are using a zilla 2k.
Start voltage 360v
End voltage 240v.
2000A continuous
20 seconds run time

Capacitance (F) = current*time/voltage change
= 2000*20/120
= 333F with a max cap voltage of 360v.
For a cap (bank?) this large, you are looking at 2900kg (6400lbs)

Matt 



**************Dell Mini Netbooks: Great deals starting at $299 after 
instant savings! 
(http://pr.atwola.com/promoclk/100126575x1221972443x1201442012/aol?redir=http:%2F%2Fad.doubleclick.net%2Fclk%3B214819441%3B36680237%3Bi)
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.sjsu.edu/mailman/private/ev/attachments/20090513/7e36ba33/attachment.html 
_______________________________________________
General EVDL support: http://evdl.org/help/
Usage guidelines: http://evdl.org/help/index.html#conv
Archives: http://evdl.org/archive/
Subscription options: http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

>
> How does one calculate the size of a super cap in farads needed to go 1/4 
> mile and supply 2000 amps at 240v for say 20 seconds?
> 

The difference,problem,benefit of capacitors vs batteries

Batteries are electrochemical storage devices, voltage is set by the
half reactions and current is limited by the rate of chemical reaction.
Just ask a cold lead battery)

Capacitors are electrostatic storage, voltage is linearly related to
state of charge and current is limited by the conductor size.

When you combine these two in parallel you only have access to only a
few percent of the capacitor's capacity.
You need a dc-dc converter to get more.

Now if you are gonna use the capacitor for primary drive in a dragster
and you have a controller that can handle it, it is feasible to get
maybe 1/2 out of it

ie zillaHV and a series dc motor 346V input and 170V motor max means
you can at least get 176V worth of full power.

_______________________________________________
General EVDL support: http://evdl.org/help/
Usage guidelines: http://evdl.org/help/index.html#conv
Archives: http://evdl.org/archive/
Subscription options: http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

Sounds like your better off putting the extra dough into more 
batteries, or better batteries.




> Jeff Shanab wrote:
> 
> >>
> >> How does one calculate the size of a super cap in farads needed to
> ...


----------



## EVDL List (Jul 27, 2007)

Wow, thats a great little cart and a very detailed page.
Thanks Jeff.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.sjsu.edu/mailman/private/ev/attachments/20090514/0d467667/attachment.html 
_______________________________________________
General EVDL support: http://evdl.org/help/
Usage guidelines: http://evdl.org/help/index.html#conv
Archives: http://evdl.org/archive/
Subscription options: http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

That's got to be a typo. The diagram for the kart clearly shows the cap in
parallel with the batteries. Caps block DC, so it could not work otherwise.
Stephen Chapman




> Dave Hymers wrote:
> >
> > Wow, thats a great little cart and a very detailed page.
> > Thanks Jeff.
> ...


----------



## EVDL List (Jul 27, 2007)

CgoKCgoKLS0tIE9uIFRodSwgNS8xNC8wOSwgZW5nYW5lYXIgPGVuZ2FuZWFyQGdtYWlsLmNvbT4g
d3JvdGU6Cgo+IAo+IFRoYXQncyBnb3QgdG8gYmUgYSB0eXBvLsKgIFRoZSBkaWFncmFtIGZvciB0
aGUga2FydAo+IGNsZWFybHkgc2hvd3MgdGhlIGNhcCBpbgo+IHBhcmFsbGVsIHdpdGggdGhlIGJh
dHRlcmllcy7CoCBDYXBzIGJsb2NrIERDLCBzbyBpdAo+IGNvdWxkIG5vdCB3b3JrIG90aGVyd2lz
ZS4KPiBTdGVwaGVuIENoYXBtYW4KPiAKClN0ZXZlLAoKVGhlIDEwLDAwMHVGLCAxMDBWIGNhcCBp
cywgYnV0IHRoZSAxMTBGLCAxNlYgVWNhcCBpcyBzd2l0Y2hlZCBpbiBhbmQgb3V0IG9mCnRoZSBz
ZXJpZXMgcGF0aCAsIGJhdHRlcnkgdG8gbW90b3IuCgpKZWZmIE0KCj4vcXVvdGU+CgpBaGgsIE9L
LiAgSSBjYW4ndCBnZXQgYmFjayBpbnRvIHRoYXQgcGFnZSBmb3Igc29tZSByZWFzb24sIGJ1dCBJ
IHdpbGwgdGFrZQp5b3VyIHdvcmQgZm9yIGl0LiAgU3RpbGwgaWYgY2FwcyBibG9jayBEQyBhbmQg
eW91IHN3aXRjaCBhIGNhcCBpbiBzZXJpZXMKd2l0aCBhIGJhdHRlcnkgYmFjaywgYXJlbid0IHlv
dSBqdXN0IHJlcGxhY2luZyB0aGUgcGFjayB3aXRoIHRoZSBjYXA/CgpTdGVwaGVuIENoYXBtYW4K
LS0gClZpZXcgdGhpcyBtZXNzYWdlIGluIGNvbnRleHQ6IGh0dHA6Ly93d3cubmFiYmxlLmNvbS9S
YWNlLVBhY2stdnMtU3RyZWV0LVBhY2stdHAyMzUwNzI4MXAyMzU0NjE2OC5odG1sClNlbnQgZnJv
bSB0aGUgRWxlY3RyaWMgVmVoaWNsZSBEaXNjdXNzaW9uIExpc3QgbWFpbGluZyBsaXN0IGFyY2hp
dmUgYXQgTmFiYmxlLmNvbS4KCgpfX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f
X19fX19fX19fXwpHZW5lcmFsIEVWREwgc3VwcG9ydDogaHR0cDovL2V2ZGwub3JnL2hlbHAvClVz
YWdlIGd1aWRlbGluZXM6IGh0dHA6Ly9ldmRsLm9yZy9oZWxwL2luZGV4Lmh0bWwjY29udgpBcmNo
aXZlczogaHR0cDovL2V2ZGwub3JnL2FyY2hpdmUvClN1YnNjcmlwdGlvbiBvcHRpb25zOiBodHRw
Oi8vbGlzdHMuc2pzdS5lZHUvbWFpbG1hbi9saXN0aW5mby9ldgoK


----------



## EVDL List (Jul 27, 2007)

Several problems I see with using supercaps.

1. If you are not using a separate bi-directional dc\dc, you won't be able 
to use much of the power in the cap. Also, once the cap has been used to 
supply some of your acceleration load, it will then draw a big uncontrolled 
surge from your batteries to charge back up, which defeats the purpose of 
using a cap in the first place.

2. You better have one heck of a big pre-charge resistor arrangement when 
you first power up the system.

Al 

_______________________________________________
General EVDL support: http://evdl.org/help/
Usage guidelines: http://evdl.org/help/index.html#conv
Archives: http://evdl.org/archive/
Subscription options: http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

I think precharging with a resistor will be impractical, they will need an
electronic charger to do that. With a resistor 1/2 the energy will be wasted
as well. If you take a fully charged capacitor and discharge it to 2/3
voltage you have taken out 1/2 the energy, Maybe capacitors initially in
parallel could be re-connected in series at the 1/2 voltage point, the
energy left at 1/2 voltage is 1/4, but re-connecting them in series gives
you the same voltage you started with but with 1/4 the capacitance and
energy left, then discharging it to 1/2 voltage again leaves you with only
1/8th of the energy you can't access.
You could take this further and have 4 capacitors that connect 4 in
parallel, the series-parallel, then series. The controller will only see a
25% voltage swing and the energy left will be 1/8 still.
Switching could be done with a diode as one of the switches in each
bank, and a contactor or semiconductor for the others.

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf
Of Al
Sent: Thursday, 14 May 2009 4:40 p.m.
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Tavrima capacitors

Several problems I see with using supercaps.

1. If you are not using a separate bi-directional dc\dc, you won't be able 
to use much of the power in the cap. Also, once the cap has been used to 
supply some of your acceleration load, it will then draw a big uncontrolled 
surge from your batteries to charge back up, which defeats the purpose of 
using a cap in the first place.

2. You better have one heck of a big pre-charge resistor arrangement when 
you first power up the system.

Al 

_______________________________________________
General EVDL support: http://evdl.org/help/
Usage guidelines: http://evdl.org/help/index.html#conv
Archives: http://evdl.org/archive/
Subscription options: http://lists.sjsu.edu/mailman/listinfo/ev


_______________________________________________
General EVDL support: http://evdl.org/help/
Usage guidelines: http://evdl.org/help/index.html#conv
Archives: http://evdl.org/archive/
Subscription options: http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

> George Tyler wrote:
> 
> > I think precharging with a resistor will be impractical, they will
> > need an
> ...


----------



## EVDL List (Jul 27, 2007)

Calculate the size of the inductor required!

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf
Of Roger Heuckeroth
Sent: Saturday, 16 May 2009 1:19 a.m.
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Tavrima capacitors




> George Tyler wrote:
> 
> > I think precharging with a resistor will be impractical, they will
> > need an
> ...


----------

