That old chestnut... Volts vs. Ah (this time with lithium batts)

[Rob Trahms]

Current config:
1989 Volkswagen Cabriolet
Zilla Z1K-HV
Impulse9 motor
16 6V US125XC batts (96V)
5-sp manual transmission

Thought experiment that I am currently going through as I prepare to upgrade my conversion with lithium batteries...

I will spend ~$5000 on new Sky Energy cells, which I will be stringing in series for my new traction pack.

Options
1) 44 SE100AHA 100 Ah batteries for 140.8V => ~14.1KWh ($5060) - 140.8 kg
2) 36 SE120AHA 120 Ah batteries for 115.2V => ~13.8KWh ($4968) - 162 kg
3) 24 SE180AHA 180 Ah batteries for 76.8V =>  ~13.8KWh ($4968) - 134.4 kg

Sky Energy batts allow for 4C continuous current, which equate for the options:
1) 400A continuous current
2) 480A continuous current
3) 720A continuous current

(I don't know what the short term current draw curve is, but these reportedly can discharge up to 12C A for 5ms.)

In all three of these options, since they are lithium I am really hoping to use up to 80% of the energy regularly.  I am interested in option 1, because it allows for the most energy with not too low a voltage.  The only concern I have with option 1 is not having enough acceleration current when its needed.

Any advice on the options here, or any experience to share?

Thanks!

[m gol]

option 1, unless you want to use a 72volt 750amp controller and want to save
$2000...(then option 3)

On Wed, Oct 28, 2009 at 5:28 PM, Rob Trahms <[hidden email]> wrote:

>
> Current config:
> 1989 Volkswagen Cabriolet
> Zilla Z1K-HV
> Impulse9 motor
> 16 6V US125XC batts (96V)
> 5-sp manual transmission
>
> Thought experiment that I am currently going through as I prepare to
> upgrade
> my conversion with lithium batteries...
>
> I will spend ~$5000 on new Sky Energy cells, which I will be stringing in
> series for my new traction pack.
>
> Options
> 1) 44 SE100AHA 100 Ah batteries for 140.8V => ~14.1KWh ($5060) - 140.8 kg
> 2) 36 SE120AHA 120 Ah batteries for 115.2V => ~13.8KWh ($4968) - 162 kg
> 3) 24 SE180AHA 180 Ah batteries for 76.8V =>  ~13.8KWh ($4968) - 134.4 kg
>
> Sky Energy batts allow for 4C continuous current, which equate for the
> options:
> 1) 400A continuous current
> 2) 480A continuous current
> 3) 720A continuous current
>
> (I don't know what the short term current draw curve is, but these
> reportedly can discharge up to 12C A for 5ms.)
>
> In all three of these options, since they are lithium I am really hoping to
> use up to 80% of the energy regularly.  I am interested in option 1,
> because
> it allows for the most energy with not too low a voltage.  The only concern
> I have with option 1 is not having enough acceleration current when its
> needed.
>
> Any advice on the options here, or any experience to share?
>
> Thanks!
>
> -----
> Rob Trahms
> [hidden email]
> Electro - the Cabby-EV
> http://chaosmgmt.blogspot.com chaosmgmt.blogspot.com
>
> --
> View this message in context:
> http://www.nabble.com/That-old-chestnut...-Volts-vs.-Ah-%28this-time-with-lithium-batts%29-tp26104889p26104889.html
> Sent from the Electric Vehicle Discussion List mailing list archive at
> Nabble.com.
>
> _______________________________________________
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>
>

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[Bill Dube]

Go with the larger volts. Less shifting. Smaller cables. More BMS
modules, however.

Bill D.

At 07:28 PM 10/28/2009, you wrote:

>Current config:
>1989 Volkswagen Cabriolet
>Zilla Z1K-HV
>Impulse9 motor
>16 6V US125XC batts (96V)
>5-sp manual transmission
>
>Thought experiment that I am currently going through as I prepare to upgrade
>my conversion with lithium batteries...
>
>I will spend ~$5000 on new Sky Energy cells, which I will be stringing in
>series for my new traction pack.
>
>Options
>1) 44 SE100AHA 100 Ah batteries for 140.8V => ~14.1KWh ($5060) - 140.8 kg
>2) 36 SE120AHA 120 Ah batteries for 115.2V => ~13.8KWh ($4968) - 162 kg
>3) 24 SE180AHA 180 Ah batteries for 76.8V =>  ~13.8KWh ($4968) - 134.4 kg
>
>Sky Energy batts allow for 4C continuous current, which equate for the
>options:
>1) 400A continuous current
>2) 480A continuous current
>3) 720A continuous current
>
>(I don't know what the short term current draw curve is, but these
>reportedly can discharge up to 12C A for 5ms.)
>
>In all three of these options, since they are lithium I am really hoping to
>use up to 80% of the energy regularly.  I am interested in option 1, because
>it allows for the most energy with not too low a voltage.  The only concern
>I have with option 1 is not having enough acceleration current when its
>needed.
>
>Any advice on the options here, or any experience to share?
>
>Thanks!
>
>-----
>Rob Trahms
>[hidden email]
>Electro - the Cabby-EV
>http://chaosmgmt.blogspot.com chaosmgmt.blogspot.com
>
>--
>View this message in context:
>http://www.nabble.com/That-old-chestnut...-Volts-vs.-Ah-%28this-time-with-lithium-batts%29-tp26104889p26104889.html
>Sent from the Electric Vehicle Discussion List mailing list archive
>at Nabble.com.
>
>_______________________________________________
>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

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[Morgan LaMoore]

On Wed, Oct 28, 2009 at 8:28 PM, Rob Trahms <[hidden email]> wrote:
> ...
> Sky Energy batts allow for 4C continuous current...
>
> (I don't know what the short term current draw curve is, but these
> reportedly can discharge up to 12C A for 5ms.)
> ...

Note how the max current is given as 12C(5ms); the continuous current
is given as 4C(20S), indicating to me that it's actually the 20 second
rating, which is effectively the same as the max rating. That also
means it's likely to change with temperature, state of charge, and who
knows what else.

-Morgan LaMoore

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[Richard Tanner-2]

Green Vehicles in San Jose has 1000 of the 180 AMP Sky Energy Batteries in
stock at a much lower cost.  I just purchased 45 from Mike and Ehab for a
150 volt system in my new S-10 conversion.
http://www.greenvehicles.com/

Richard

-----Original Message-----
From: [hidden email] [mailto:[hidden email]] On Behalf
Of Rob Trahms
Sent: Wednesday, October 28, 2009 6:29 PM
To: [hidden email]
Subject: [EVDL] That old chestnut... Volts vs. Ah (this time with lithium
batts)


Current config:
1989 Volkswagen Cabriolet
Zilla Z1K-HV
Impulse9 motor
16 6V US125XC batts (96V)
5-sp manual transmission

Thought experiment that I am currently going through as I prepare to upgrade
my conversion with lithium batteries...

I will spend ~$5000 on new Sky Energy cells, which I will be stringing in
series for my new traction pack.

Options
1) 44 SE100AHA 100 Ah batteries for 140.8V => ~14.1KWh ($5060) - 140.8 kg
2) 36 SE120AHA 120 Ah batteries for 115.2V => ~13.8KWh ($4968) - 162 kg
3) 24 SE180AHA 180 Ah batteries for 76.8V =>  ~13.8KWh ($4968) - 134.4 kg

Sky Energy batts allow for 4C continuous current, which equate for the
options:
1) 400A continuous current
2) 480A continuous current
3) 720A continuous current

(I don't know what the short term current draw curve is, but these
reportedly can discharge up to 12C A for 5ms.)

In all three of these options, since they are lithium I am really hoping to
use up to 80% of the energy regularly.  I am interested in option 1, because
it allows for the most energy with not too low a voltage.  The only concern
I have with option 1 is not having enough acceleration current when its
needed.

Any advice on the options here, or any experience to share?

Thanks!

-----
Rob Trahms
[hidden email]
Electro - the Cabby-EV
http://chaosmgmt.blogspot.com chaosmgmt.blogspot.com

--
View this message in context:
http://www.nabble.com/That-old-chestnut...-Volts-vs.-Ah-%28this-time-with-li
thium-batts%29-tp26104889p26104889.html
Sent from the Electric Vehicle Discussion List mailing list archive at
Nabble.com.

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[John G. Lussmyer]

Richard Tanner wrote:
> Green Vehicles in San Jose has 1000 of the 180 AMP Sky Energy Batteries in
> stock at a much lower cost.  I just purchased 45 from Mike and Ehab for a
> 150 volt system in my new S-10 conversion.
> http://www.greenvehicles.com/
>  
They might, but you sure can't prove it from that website.  (and it's one of those flash-abortion only sites as well.  ick.)


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[tomw]

Although SkyEnergy (and Thundersky) recently upgraded their specs, I think most people are still trying to keep discharge current under 3C.  Most expect you will take a hit on lifetime with regular use of higher discharge currents, even those within spec.  Of course there is no data available in the US supporting or refuting this yet.

Tom

Rob Trahms wrote:

Current config:
1989 Volkswagen Cabriolet
Zilla Z1K-HV
Impulse9 motor
16 6V US125XC batts (96V)
5-sp manual transmission

Thought experiment that I am currently going through as I prepare to upgrade my conversion with lithium batteries...

I will spend ~$5000 on new Sky Energy cells, which I will be stringing in series for my new traction pack.

Options
1) 44 SE100AHA 100 Ah batteries for 140.8V => ~14.1KWh ($5060) - 140.8 kg
2) 36 SE120AHA 120 Ah batteries for 115.2V => ~13.8KWh ($4968) - 162 kg
3) 24 SE180AHA 180 Ah batteries for 76.8V =>  ~13.8KWh ($4968) - 134.4 kg

Sky Energy batts allow for 4C continuous current, which equate for the options:
1) 400A continuous current
2) 480A continuous current
3) 720A continuous current

(I don't know what the short term current draw curve is, but these reportedly can discharge up to 12C A for 5ms.)

In all three of these options, since they are lithium I am really hoping to use up to 80% of the energy regularly.  I am interested in option 1, because it allows for the most energy with not too low a voltage.  The only concern I have with option 1 is not having enough acceleration current when its needed.

Any advice on the options here, or any experience to share?

Thanks!

[shred]

I bought TS 40 AH modules for my motorcycle at the same time my friend bought 40s paired up for an effective 80ah set of batteries for his Xebra. He drove his Xebra 4 days a week to work which was about a 25 mile drive each way (80% DOD is my guess) he charged at both ends. He was drawing 2c – 3c continuous most of the way. His pack died in just a few months. Myself and a few others that have had some experience with TS have concluded that keeping the continuous discharge at 1c or less is required for the longevity of the battery.

tomofreno wrote:

Although SkyEnergy (and Thundersky) recently upgraded their specs, I think most people are still trying to keep discharge current under 3C.  Most expect you will take a hit on lifetime with regular use of higher discharge currents, even those within spec.  Of course there is no data available in the US supporting or refuting this yet.

Tom

Rob Trahms wrote:

Current config:
1989 Volkswagen Cabriolet
Zilla Z1K-HV
Impulse9 motor
16 6V US125XC batts (96V)
5-sp manual transmission

Thought experiment that I am currently going through as I prepare to upgrade my conversion with lithium batteries...

I will spend ~$5000 on new Sky Energy cells, which I will be stringing in series for my new traction pack.

Options
1) 44 SE100AHA 100 Ah batteries for 140.8V => ~14.1KWh ($5060) - 140.8 kg
2) 36 SE120AHA 120 Ah batteries for 115.2V => ~13.8KWh ($4968) - 162 kg
3) 24 SE180AHA 180 Ah batteries for 76.8V =>  ~13.8KWh ($4968) - 134.4 kg

Sky Energy batts allow for 4C continuous current, which equate for the options:
1) 400A continuous current
2) 480A continuous current
3) 720A continuous current

(I don't know what the short term current draw curve is, but these reportedly can discharge up to 12C A for 5ms.)

In all three of these options, since they are lithium I am really hoping to use up to 80% of the energy regularly.  I am interested in option 1, because it allows for the most energy with not too low a voltage.  The only concern I have with option 1 is not having enough acceleration current when its needed.

Any advice on the options here, or any experience to share?

Thanks!

[Roger Heuckeroth]

I would chose option 1 also. The Zilla exchanges voltage for current,  
so acceleration current will not be a problem. 400 amps at 140v is  
equivalent to 800 amps at 70v. And with lower current on the battery  
side, there will be lower losses in your battery interconnects.

Sent from my iPhone

On Oct 28, 2009, at 9:28 PM, Rob Trahms <[hidden email]> wrote:

>
> Current config:
> 1989 Volkswagen Cabriolet
> Zilla Z1K-HV
> Impulse9 motor
> 16 6V US125XC batts (96V)
> 5-sp manual transmission
>
> Thought experiment that I am currently going through as I prepare to  
> upgrade
> my conversion with lithium batteries...
>
> I will spend ~$5000 on new Sky Energy cells, which I will be  
> stringing in
> series for my new traction pack.
>
> Options
> 1) 44 SE100AHA 100 Ah batteries for 140.8V => ~14.1KWh ($5060) -  
> 140.8 kg
> 2) 36 SE120AHA 120 Ah batteries for 115.2V => ~13.8KWh ($4968) - 162  
> kg
> 3) 24 SE180AHA 180 Ah batteries for 76.8V =>  ~13.8KWh ($4968) -  
> 134.4 kg
>
> Sky Energy batts allow for 4C continuous current, which equate for the
> options:
> 1) 400A continuous current
> 2) 480A continuous current
> 3) 720A continuous current
>
> (I don't know what the short term current draw curve is, but these
> reportedly can discharge up to 12C A for 5ms.)
>
> In all three of these options, since they are lithium I am really  
> hoping to
> use up to 80% of the energy regularly.  I am interested in option 1,  
> because
> it allows for the most energy with not too low a voltage.  The only  
> concern
> I have with option 1 is not having enough acceleration current when  
> its
> needed.
>
> Any advice on the options here, or any experience to share?
>
> Thanks!
>
> -----
> Rob Trahms
> [hidden email]
> Electro - the Cabby-EV
> http://chaosmgmt.blogspot.com chaosmgmt.blogspot.com
>
> --
> View this message in context: http://www.nabble.com/That-old-chestnut...-Volts-vs.-Ah-%28this-time-with-lithium-batts%29-tp26104889p26104889.html
> Sent from the Electric Vehicle Discussion List mailing list archive  
> at Nabble.com.
>
> _______________________________________________
> 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
>

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[Jon Glauser-2]

Go with the highest voltage you can. With your 9" motor, you want the
higher voltage to get any torque at higher RPMs. And with a zilla, set
your battery current limit to something you feel is safe (350A?). That
should be plenty of power to move you! (I get 300A@84V (34HP)...
you'll get 350A@100V (47HP) I assumed a voltage sag there, I really
have no idea but it gives a ball park.

I'm wishing I had a higher voltage than 96V. and I have 1000lbs
(453kg) of lead to move around!

-Jon Glauser
http://jonglauser.blogspot.com
http://www.evalbum.com/555

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[storm connors]

On my Suzuki Samurai which with its lead should weigh more than your
Cabriolet gives adequate acceleration with its 144V pack limited to
200A.

On Wed, Oct 28, 2009 at 9:28 PM, Rob Trahms <[hidden email]> wrote:

>
> Current config:
> 1989 Volkswagen Cabriolet
> Zilla Z1K-HV
> Impulse9 motor
> 16 6V US125XC batts (96V)
> 5-sp manual transmission
>
> Thought experiment that I am currently going through as I prepare to upgrade
> my conversion with lithium batteries...
>
> I will spend ~$5000 on new Sky Energy cells, which I will be stringing in
> series for my new traction pack.
>
> Options
> 1) 44 SE100AHA 100 Ah batteries for 140.8V => ~14.1KWh ($5060) - 140.8 kg
> 2) 36 SE120AHA 120 Ah batteries for 115.2V => ~13.8KWh ($4968) - 162 kg
> 3) 24 SE180AHA 180 Ah batteries for 76.8V =>  ~13.8KWh ($4968) - 134.4 kg
>
> Sky Energy batts allow for 4C continuous current, which equate for the
> options:
> 1) 400A continuous current
> 2) 480A continuous current
> 3) 720A continuous current
>
> (I don't know what the short term current draw curve is, but these
> reportedly can discharge up to 12C A for 5ms.)
>
> In all three of these options, since they are lithium I am really hoping to
> use up to 80% of the energy regularly.  I am interested in option 1, because
> it allows for the most energy with not too low a voltage.  The only concern
> I have with option 1 is not having enough acceleration current when its
> needed.
>
> Any advice on the options here, or any experience to share?
>
> Thanks!
>
> -----
> Rob Trahms
> [hidden email]
> Electro - the Cabby-EV
> http://chaosmgmt.blogspot.com chaosmgmt.blogspot.com
>
> --
> View this message in context: http://www.nabble.com/That-old-chestnut...-Volts-vs.-Ah-%28this-time-with-lithium-batts%29-tp26104889p26104889.html
> Sent from the Electric Vehicle Discussion List mailing list archive at Nabble.com.
>
> _______________________________________________
> 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
>
>

--
http://www.austinev.org/evalbum/1059
http://stormselectric.blogspot.com/
Storm

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