battery help

I am looking at getting some batteries that will make my 28 mile commute.  I have a prestolite MTC4001, and a curtis 1231C, in the old style bug.  I would like to run between 120 v and 144 v, because of the DC-DC I have.  I would like to have some battery recommendations.  I have heard the suggestion that T-105 would be good, but that might be getting a bit on the heavy side for my car.  I think that I could fit 1200 lbs of batteries.  I at one point considered 30 XHS, but saw on the evalbum, someone had a bad experience.  Does anyone else have any experience?  I have heard that some have bad experience with the 8V batteries, but others like it.

My requirements:  28 mile commute consistent for the next 4 months.  After that, it will be no more than 10 miles.  But occasionally I would still like to be able to drive the 30 miles or so.

What are good batteries to use.  And if you know of good prices, I would appreciate that as well.

Thanks,
Brian
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[Bob Bath]

Hi,
   Don't know if your 28 mi. commute is in warm, or
cold weather, or both.  I'm running 144V of US Battery
8V, and they would definitely take you the distance,
no matter what the weather.  Whether the bug could
handle the weight... that's another matter.
Best of luck with your decision.
Sincerely,

--- "[hidden email]" <[hidden email]> wrote:

> I am looking at getting some batteries that will
> make my 28 mile commute.  I have a prestolite
> MTC4001, and a curtis 1231C, in the old style bug.
> I would like to run between 120 v and 144 v, because
> of the DC-DC I have.  I would like to have some
> battery recommendations.  I have heard the
> suggestion that T-105 would be good, but that might
> be getting a bit on the heavy side for my car.  I
> think that I could fit 1200 lbs of batteries.  I at
> one point considered 30 XHS, but saw on the evalbum,
> someone had a bad experience.  Does anyone else have
> any experience?  I have heard that some have bad
> experience with the 8V batteries, but others like
> it.
>
> My requirements:  28 mile commute consistent for the
> next 4 months.  After that, it will be no more than
> 10 miles.  But occasionally I would still like to be
> able to drive the 30 miles or so.
>
> What are good batteries to use.  And if you know of
> good prices, I would appreciate that as well.
>
> Thanks,
> Brian
> ---- Msg sent via @=WebMail -
> http://webmail.usu.edu/
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>

Converting a gen. 5 Honda Civic?  For $20 DVD you can purchase footage of my '92 sedan, as well as a del Sol and hatch too!
Learn more at: www.budget.net/~bbath/CivicWithACord.html          ____
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[Roland Wiench]

Let say a set of batteries in your rig uses about 2 AH per mile, so to go 28
miles, this would required a minimum of 56 AH battery if you want to
discharge it down to 100% DOD which is not good.  It is best to keep at or
above 50% DOD, so this now makes the battery AH at 112 AH.

But, a EV is not normally driven at the 20 hour AH rate, meaning a 220 AH
battery would have to be discharge at no more then 11 amps per hour for 20
hours.

The T-105 battery is rated for 225 AH, and at 75 amps it has a reserved
capacity of 115 minutes.  The more amps you draw from the battery, the
amount of reserved minutes is reduce, thus the AH becomes:

                    115 mins / 60 = 1.9 hrs

                    1.9 hrs x 75 amps = 142 AH

Discharging this type of battery to 50% DOD is about 71 AH.

A EV using 2 AH per mile, will be about a 35 miles range.

To get 2 AH per mile, you would have to drive non-stop, not stopping and
acceleration at each light, no hill climbing or grades and stay under 75
battery amps.

But normally you may be as high as 4 AH per mile at times, so lets say the
average is about 3 AH per mile.  Then your range may be 71/3= 24 miles at
50% D0D  or average of (35+24)/2 = 29 miles.  Looks like you will just make
it with a 225 AH battery.

Roland




----- Original Message -----
From: <[hidden email]>
To: "Electric Vehicle Discussion List" <[hidden email]>
Sent: Thursday, August 16, 2007 7:00 AM
Subject: [EVDL] battery help

> I am looking at getting some batteries that will make my 28 mile commute.
> I have a prestolite MTC4001, and a curtis 1231C, in the old style bug.  I
> would like to run between 120 v and 144 v, because of the DC-DC I have.  I
> would like to have some battery recommendations.  I have heard the
> suggestion that T-105 would be good, but that might be getting a bit on
> the heavy side for my car.  I think that I could fit 1200 lbs of
> batteries.  I at one point considered 30 XHS, but saw on the evalbum,
> someone had a bad experience.  Does anyone else have any experience?  I
> have heard that some have bad experience with the 8V batteries, but others
> like it.
>
> My requirements:  28 mile commute consistent for the next 4 months.  After
> that, it will be no more than 10 miles.  But occasionally I would still
> like to be able to drive the 30 miles or so.
>
> What are good batteries to use.  And if you know of good prices, I would
> appreciate that as well.
>
> Thanks,
> Brian
> ---- Msg sent via @=WebMail - http://webmail.usu.edu/
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>

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[Lee Hart]

[hidden email] wrote:
> I am looking at getting some batteries that will make my 28 mile
> commute... Prestolite MTC4001, Curtis 1231C, in the old style bug...
> 120-144v... I would like to have some battery recommendations.

You've had lots of good comments so far. I can add a few.

6v golf cart batteries would be great. They can easily meet your range
requirements. They last a long time, and will give you the lowest cost
per mile. But they are pretty heavy for a bug; 120-144v worth is
1200-1600 lbs.

8v golf cart batteries should also work well. The range would be less,
but with care can still make your commute (avoid fast acceleration and
high speed driving). Cost per mile will be a little higher; they cost
less initially, but more than make up for it with shorter life. They
will be lighter, at 1000-1200 lbs.

12v batteries like the 30XHS would be a poor choice. Life will be very
short, and it's unlikely they would give you the range you seek unless
you drive very slow and conservatively.

The Curtis 1231 is easily capable of drawing enough battery current to
shorten the life of your batteries. I'd suggest turning its current
limit pot (on the side of the case behind the screw) all the way down to
keep yourself from inadvertently ruining the batteries by overdoing it.
--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in    --    Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net

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[David Roden]

On 16 Aug 2007 at 7:00, [hidden email] wrote:

> I am looking [for] batteries that will make my 28 mile commute.

Is that 28mi one way, or round-trip?  

Can you charge at work?  If yes, it'll be MUCH easier.

David Roden - Akron, Ohio, USA
EVDL Administrator

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[storm connors]

I went through the same agony trying to figure out how to power the Suzuki.
It is a small vehicle like your bug. I ended up with the Goldilocks decision
of 18  8v golf cart batteries for a total weight  of 3,030 pounds.  I am
finding  for myself what the rest already know. The  whole effect depends on
how you drive it. Last weekend I went 33 miles on 99 amp hours.  There was
still capacity left. This is on very hilly terrain. I avoid going over 200
battery amps if possible. On some of the local hills it's tough, but the
right foot can be trained. OTOH, 70mph and jackrabit starts can take me over
5 amp hours per mile with, I expect, a corresponding drop in battery life.

Anyway, you will probably come to the same conclusion I did. 120-144v of 8v
FLAs. Plan not to abuse them.

On 8/16/07, Lee Hart <[hidden email]> wrote:

>
> [hidden email] wrote:
> > I am looking at getting some batteries that will make my 28 mile
> > commute... Prestolite MTC4001, Curtis 1231C, in the old style bug...
> > 120-144v... I would like to have some battery recommendations.
>
> You've had lots of good comments so far. I can add a few.
>
> 6v golf cart batteries would be great. They can easily meet your range
> requirements. They last a long time, and will give you the lowest cost
> per mile. But they are pretty heavy for a bug; 120-144v worth is
> 1200-1600 lbs.
>
> 8v golf cart batteries should also work well. The range would be less,
> but with care can still make your commute (avoid fast acceleration and
> high speed driving). Cost per mile will be a little higher; they cost
> less initially, but more than make up for it with shorter life. They
> will be lighter, at 1000-1200 lbs.
>
> 12v batteries like the 30XHS would be a poor choice. Life will be very
> short, and it's unlikely they would give you the range you seek unless
> you drive very slow and conservatively.
>
> The Curtis 1231 is easily capable of drawing enough battery current to
> shorten the life of your batteries. I'd suggest turning its current
> limit pot (on the side of the case behind the screw) all the way down to
> keep yourself from inadvertently ruining the batteries by overdoing it.
> --
> Ring the bells that still can ring
> Forget the perfect offering
> There is a crack in everything
> That's how the light gets in    --    Leonard Cohen
> --
> Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>

--
http://www.austinev.org/evalbum/1059
http://stormselectric.blogspot.com/
Storm
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It is 28 miles round trip.  I should be able to charge at the halfway point as well.

What is your suggestion on batteries?

Brian


 On Thu Aug 16  9:54 , David Roden <[hidden email]> sent:

>On 16 Aug 2007 at 7:00, [hidden email] wrote:
>
>> I am looking [for] batteries that will make my 28 mile commute.
>
>Is that 28mi one way, or round-trip?  
>
>Can you charge at work?  If yes, it'll be MUCH easier.
>
>David Roden - Akron, Ohio, USA
>EVDL Administrator
>
>= = = = = = = = = = = = = = = = = = = = = = = = = = = = =
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>
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[David Roden]

On 16 Aug 2007 at 10:29, [hidden email] wrote:

> It is 28 miles round trip.  I should be able to charge at the halfway point as
> well.
>
> What is your suggestion on batteries?

If you can get one-third of the vehicle weight in golf car batteries, you'll
have a practical 40 mile range at moderate spees.  This should be plenty to
handle your commute even if you can't charge during the day.

Voltage is unimportant for range.  If your empty glider weighs, say, 1600
lb, figure 800-900 lb of lead.  That's 12 to 14 golf car batteries.  Then,
in an ideal world, you'd choose your controller and motor to operate on 72 -
84 volts and produce around 40kW to provide adequate acceleration
performance.  With a DC series motor, this would mean a 500 to 600 amp
controller.

Since you already have the controller and motor, your choices are more
limited.  I think 72v is too low for a 1231C.  You might consider using 15 8-
volt golf car batteries.  They're a decent compromise between 6v life and
12v voltage.  Don't draw more than 375 amps from them if you can help it.  
This would be 45kW, which should be more than enough for 1960s VW Bug
performance.

David Roden - Akron, Ohio, USA
EVDL Administrator

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[John A. Evans - N0HJ]

Hi David et al.,

  I have a question about your statement that voltage is unimportant for
range.  I realize that providing current determines range (as long as
you can provide X amps, you can keep going) and that voltage equates to
speed.  However, doesn't adding additional series batteries (like going
from say, 96V to 108V) add capacity and thus increase range?  Since you
have more batteries/lead, don't they provide more capacity and hence
more range?  It is certainly easier for 18 6volt golf cart batteries to
provide, say, 200 amps than it is for 16 6volt batteries.  I've heard
folks argue that adding batteries won't give extra range, so I thought
I'd ask for clarification.

tnx,
john

David Roden wrote:
> Voltage is unimportant for range.

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[Joseph T.]

John,

   I  know where you are coming from, but I think you might be
incorrect. (sorry!) Here's a run down:

            More amp-HOURS is what provides more range. An amp-HOUR is
one amp running for one hour, so more amp-hours means that the battery
can run longer, and therefore give you more range.

          Adding more batteries, or making the battery cells larger
will increase range. Now, when you add more batteries you do increase
voltage and range. However, you can have a battery pack with more
volts have less range than a battery pack with LESS volts. How? The
battery with less voltage can have more amp-hours, and because it has
more amp-hours, and therefore a longer running time, it gives the
vehicle more range. You can though, increase range by adding more
batteries, which also gives you more voltage.

     I think a better, and easier way, to measure how far battery pack
will take you is simply with kilowatt-hours.

On 8/16/07, John A. Evans - N0HJ <[hidden email]> wrote:

> Hi David et al.,
>
>  I have a question about your statement that voltage is unimportant for
> range.  I realize that providing current determines range (as long as
> you can provide X amps, you can keep going) and that voltage equates to
> speed.  However, doesn't adding additional series batteries (like going
> from say, 96V to 108V) add capacity and thus increase range?  Since you
> have more batteries/lead, don't they provide more capacity and hence
> more range?  It is certainly easier for 18 6volt golf cart batteries to
> provide, say, 200 amps than it is for 16 6volt batteries.  I've heard
> folks argue that adding batteries won't give extra range, so I thought
> I'd ask for clarification.
>
> tnx,
> john
>
> David Roden wrote:
> > Voltage is unimportant for range.
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>

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[Morgan LaMoore]

Joe,

I'd disagree. If you're using a battery with higher voltage, the controller
can use a lower duty cycle to get the same speed. Lower duty cycle means
less average current drawn from the batteries. Less current drawn from the
batteries means longer range. In an ideal world, they would trade off
perfectly, and your range would depend on only capacity (in Watt-hours, not
amp-hours).

Of course, the real world has inefficiencies and imperfections that mess
with things. At higher currents, you lose much more power in the wires (I^2R
losses); higher voltage at lower currents lowers these losses. At higher
voltages, you may get more iron losses from the magnetics (depending on type
of motor), or the motor controller may be less efficient if it is running at
a very low duty cycle. So you have to find a balance between voltage and
current. You don't see many EV's putting 15 6V batteries in parallel!

What matters is energy storage, not just amp storage. Energy is what makes
the world go.

-Morgan LaMoore

On 8/16/07, Joseph T. <[hidden email]> wrote:

>
> John,
>
>    I  know where you are coming from, but I think you might be
> incorrect. (sorry!) Here's a run down:
>
>             More amp-HOURS is what provides more range. An amp-HOUR is
> one amp running for one hour, so more amp-hours means that the battery
> can run longer, and therefore give you more range.
>
>           Adding more batteries, or making the battery cells larger
> will increase range. Now, when you add more batteries you do increase
> voltage and range. However, you can have a battery pack with more
> volts have less range than a battery pack with LESS volts. How? The
> battery with less voltage can have more amp-hours, and because it has
> more amp-hours, and therefore a longer running time, it gives the
> vehicle more range. You can though, increase range by adding more
> batteries, which also gives you more voltage.
>
>      I think a better, and easier way, to measure how far battery pack
> will take you is simply with kilowatt-hours.
>
> On 8/16/07, John A. Evans - N0HJ <[hidden email]> wrote:
> > Hi David et al.,
> >
> >  I have a question about your statement that voltage is unimportant for
> > range.  I realize that providing current determines range (as long as
> > you can provide X amps, you can keep going) and that voltage equates to
> > speed.  However, doesn't adding additional series batteries (like going
> > from say, 96V to 108V) add capacity and thus increase range?  Since you
> > have more batteries/lead, don't they provide more capacity and hence
> > more range?  It is certainly easier for 18 6volt golf cart batteries to
> > provide, say, 200 amps than it is for 16 6volt batteries.  I've heard
> > folks argue that adding batteries won't give extra range, so I thought
> > I'd ask for clarification.
> >
> > tnx,
> > john
> >
> > David Roden wrote:
> > > Voltage is unimportant for range.
> >
> > _______________________________________________
> > For subscription options, see
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> >
>
> _______________________________________________
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[David Roden]

> I realize that providing current determines range

Not quite.  Current gives you torque and torque provides acceleration.

> voltage equates to speed

It depends on the situation.  Sometimes this happens.  Not always.  Voltage
is not the only factor influencing top speed.  A motor and controller system
can be designed to give you almost any top speed from almost any voltage.  
That's why I say the best way to design an EV is to start by determing what
battery will serve your needs, then design the rest of the drive system to
work with the battery.

> Since you have more batteries/lead, don't they provide more
> capacity and hence more range?

Again, there are various factors in play.  But in general, lead is your
fuel; more of it gives you more range.  You can get more lead by using more
batteries.  You can also get more lead by using fewer batteries, but larger
ones.  

Someone mentioned amp-hours as proportional to range.  This isn't quite
right either, unless voltage is held constant.  Range is influenced by Watt-
hours of energy storage.  

David Roden - Akron, Ohio, USA
EVDL Administrator

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[Jeff Shanab]

Like David said range is by wh

Analogy is
    gals * miles/gal           = miles range
    usable kwh / (wh/mile) = miles range  (some people use miles/wh just
to make the analogy stronger)

My ev gets an awful 400ish wh/mile
I have 24 orbitals that are 36ah at 1 hr rate
24*12*36=10kwh *.8=8.3kwh/400(wh/m) = 21 miles (the .8 is never take
lead below 20%soc)

That is a maximum on a new pack and at 16 miles the voltage sag is too
much for my liking. I think part of the reason my first pack got
murdered was that I use my power in 1/2 hour. The batteries are more
probably more like 24ah; which works out to 17 miles. After I switched
jobs where i was no longer topping off at work and the weather turned
cold the 12 miles I was driving dipped below the 20%soc.

I know the mileage(wh/mile) is dismal. but at least 3 people in the last
month from work, who drive similar route, have commented on the fact
that the EV is not slow. They all seem surprised. (just wait until i get
the lifepo4 pack!)



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[John A. Evans - N0HJ]

Thanks David and all,

  I was really just looking for confirmation that adding two additional
batteries to the voltsrabbit design would boost the range.  Of course, I
should know that I really need to be correct and explicit in my
terminology when I ask questions here.

Thanks again,
John

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[Joseph T.]

"I was really just looking for confirmation that adding two additional
batteries to the voltsrabbit design would boost the range."

Adding two batteries will definitely give you more range. If you'd
like to mess around with different EV configurations you can go to
evconvert.com for their EV calculator.


On 8/17/07, John A. Evans - N0HJ <[hidden email]> wrote:

> Thanks David and all,
>
>  I was really just looking for confirmation that adding two additional
> batteries to the voltsrabbit design would boost the range.  Of course, I
> should know that I really need to be correct and explicit in my
> terminology when I ask questions here.
>
> Thanks again,
> John
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>

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[joe-22]

Wait a minute, guys - as has been stated before, adding batteries will NOT
necessarily give you more range! It will give you somewhat better
performance, all else being equal. The amp-hours remains the same for any
number of batteries connected in series, and the additional weight will
negate most of the benefit beyond a certain point.

Batteries connected in parallel will give more range, batteries connected in
series will boost performance.

Joseph H. Strubhar

Web: www.gremcoinc.com

E-mail: [hidden email]
----- Original Message -----
From: "Joseph T. " <[hidden email]>
To: "Electric Vehicle Discussion List" <[hidden email]>
Sent: Friday, August 17, 2007 10:06 PM
Subject: Re: [EVDL] battery help

> "I was really just looking for confirmation that adding two additional
> batteries to the voltsrabbit design would boost the range."
>
> Adding two batteries will definitely give you more range. If you'd
> like to mess around with different EV configurations you can go to
> evconvert.com for their EV calculator.
>
>
> On 8/17/07, John A. Evans - N0HJ <[hidden email]> wrote:
>> Thanks David and all,
>>
>>  I was really just looking for confirmation that adding two additional
>> batteries to the voltsrabbit design would boost the range.  Of course, I
>> should know that I really need to be correct and explicit in my
>> terminology when I ask questions here.
>>
>> Thanks again,
>> John
>>
>> _______________________________________________
>> For subscription options, see
>> http://lists.sjsu.edu/mailman/listinfo/ev
>>
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>

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[damon henry]

Joseph,
 
You've been working too hard this summer.  Adding batteries and leaving everything else the same will always add range.  In fact in the case of lead acid batteries the range can be determined almost exclusively by how much weight in batteries you are carrying.  Whether they are in series or parallel makes very little difference.
 
BTW - I should be down at the track watching the Nedra guys run right now, but it's looking like a possible rain out tonight.  I called Wayland about a half hour ago and they had cars lined up on the track trying to keep it dry hoping the rain will pass.
 
damon> Wait a minute, guys - as has been stated before, adding batteries will NOT > necessarily give you more range! It will give you somewhat better > performance, all else being equal. The amp-hours remains the same for any > number of batteries connected in series, and the additional weight will > negate most of the benefit beyond a certain point.> > Batteries connected in parallel will give more range, batteries connected in > series will boost performance.> > Joseph H. Strubhar>
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[Morgan LaMoore]

Joe,

No. Even though the pack has the same amp-hours, adding more batteries in
series will still add range. Here's why:

Say that at cruising speed, your motor needs 50V and 100A. Further say that
you have a 72V 120 amp-hour battery pack. The controller acts as a buck
converter, switching one terminal of the motor between power and ground. The
motor acts as both the inductor and the load of the boost converter. For
more about Buck converters, look at "Buck_Converter" on Wikipedia.

The duty cycle of the converter is Vo/Vin=50V/72V=0.694. So for 69% of the
time, 100 amps are coming from the battery, and for 31% of the time, 100
amps are coming from the stored energy inside of the coil. This means that
an average of 69.4 amps are being drawn from the battery.

Now say that you add more identical batteries and are now at 96V, still 120
amp-hours. Your motor still needs 50V and 100A to go at cruising speed. Now
the duty cycle of the converter is D=Vo/Vin=50/96=0.521. Now with a duty
cycle of 52.1%, you are only drawing 100A from the battery 52.1% of the
time, for an average of 52.1 amps from the battery.

Even though the number of amp-hours stays the same, when you add more
batteries in series, you draw less amps from the batteries, so they last
longer.

-Morgan LaMoore

On 8/18/07, joe <[hidden email]> wrote:

>
> Wait a minute, guys - as has been stated before, adding batteries will NOT
> necessarily give you more range! It will give you somewhat better
> performance, all else being equal. The amp-hours remains the same for any
> number of batteries connected in series, and the additional weight will
> negate most of the benefit beyond a certain point.
>
> Batteries connected in parallel will give more range, batteries connected
> in
> series will boost performance.
>
> Joseph H. Strubhar
>
> Web: www.gremcoinc.com
>
> E-mail: [hidden email]
> ----- Original Message -----
> From: "Joseph T. " <[hidden email]>
> To: "Electric Vehicle Discussion List" <[hidden email]>
> Sent: Friday, August 17, 2007 10:06 PM
> Subject: Re: [EVDL] battery help
>
>
> > "I was really just looking for confirmation that adding two additional
> > batteries to the voltsrabbit design would boost the range."
> >
> > Adding two batteries will definitely give you more range. If you'd
> > like to mess around with different EV configurations you can go to
> > evconvert.com for their EV calculator.
> >
> >
> > On 8/17/07, John A. Evans - N0HJ <[hidden email]> wrote:
> >> Thanks David and all,
> >>
> >>  I was really just looking for confirmation that adding two additional
> >> batteries to the voltsrabbit design would boost the range.  Of course,
> I
> >> should know that I really need to be correct and explicit in my
> >> terminology when I ask questions here.
> >>
> >> Thanks again,
> >> John
> >>
> >> _______________________________________________
> >> For subscription options, see
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> >>
> >
> > _______________________________________________
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> >
>
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[Cor van de Water]

Correct,

Adding batteries will always increase the amount of
energy that you are carrying and it is the energy that
gives you range.
You can easily see that from the reasoning that Joe used:
Adding batteries in series will not give more Ah, so he
drew the (false) conclusion that the range will not
increase when the Ah stay the same and only the voltage
increases. But if you look at how a controller works then
you see that the controller will perform a task called
"current multiplication" when the output voltage is
lower than the input voltage, (almost) equal to the
rate between the two.
Eaxmple: 120V and 100A input from the battery pack can
result in 60V and (almost) 200A output into the motor,
to maintain a certain driving speed.
Both are (almost) the same amount of power: 12kW.
Now if two batteries are added to the pack, the same
power is delivered at 144V when the batteries deliver
approx 80A.
This means that each battery delivers less power and
this means that it can deliver the required power for
a longer period, because the total energy contained
in the pack is increased by adding batteries.

Hope this clarifies,

Cor van de Water
Systems Architect
Proxim Wireless Corporation http://www.proxim.com
Email: [hidden email]    Private: http://www.cvandewater.com
Skype: cor_van_de_water     IM: [hidden email]
Tel: [phone]    VoIP: [phone] FWD# 25925
Fax: [phone]    eFAX: [phone]
Second Life: www.secondlife.com/?u=3b42cb3f4ae249319edb487991c30acb

-----Original Message-----
From: [hidden email] [mailto:[hidden email]] On Behalf Of damon henry
Sent: Saturday, August 18, 2007 8:19 PM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] battery help


Joseph,
 
You've been working too hard this summer.  Adding batteries and leaving everything else the same will always add range.  In fact in the case of lead acid batteries the range can be determined almost exclusively by how much weight in batteries you are carrying.  Whether they are in series or parallel makes very little difference.
 
BTW - I should be down at the track watching the Nedra guys run right now, but it's looking like a possible rain out tonight.  I called Wayland about a half hour ago and they had cars lined up on the track trying to keep it dry hoping the rain will pass.
 
damon> Wait a minute, guys - as has been stated before, adding batteries
damon> will NOT > necessarily give you more range! It will give you
damon> somewhat better > performance, all else being equal. The
damon> amp-hours remains the same for any > number of batteries
damon> connected in series, and the additional weight will > negate most
damon> of the benefit beyond a certain point.> > Batteries connected in
damon> parallel will give more range, batteries connected in > series
damon> will boost performance.> > Joseph H. Strubhar>
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[joe-22]

I  grant you that it may give you more life from the batteries, but it
doesn't add mileage to your range, as much as the math would indicate. I
know, I tried it! I went from 96V to 120V to 144V on my Datsun pickup, and I
got better performance, but practically the same range. Why? Because the
amphours that the batteries contain remains the same, and that is what
determines the range. Yes,  increasing the lbs of lead theorically will
increase range, but as a practical fact, it doesn't to a significant amount,
unless you have  the batteries in series.

Joseph H. Strubhar

Web: www.gremcoinc.com

E-mail: [hidden email]

----- Original Message -----
From: "Morgan LaMoore" <[hidden email]>
To: "Electric Vehicle Discussion List" <[hidden email]>
Sent: Saturday, August 18, 2007 8:52 PM
Subject: Re: [EVDL] battery help

> Joe,
>
> No. Even though the pack has the same amp-hours, adding more batteries in
> series will still add range. Here's why:
>
> Say that at cruising speed, your motor needs 50V and 100A. Further say
> that
> you have a 72V 120 amp-hour battery pack. The controller acts as a buck
> converter, switching one terminal of the motor between power and ground.
> The
> motor acts as both the inductor and the load of the boost converter. For
> more about Buck converters, look at "Buck_Converter" on Wikipedia.
>
> The duty cycle of the converter is Vo/Vin=50V/72V=0.694. So for 69% of the
> time, 100 amps are coming from the battery, and for 31% of the time, 100
> amps are coming from the stored energy inside of the coil. This means that
> an average of 69.4 amps are being drawn from the battery.
>
> Now say that you add more identical batteries and are now at 96V, still
> 120
> amp-hours. Your motor still needs 50V and 100A to go at cruising speed.
> Now
> the duty cycle of the converter is D=Vo/Vin=50/96=0.521. Now with a duty
> cycle of 52.1%, you are only drawing 100A from the battery 52.1% of the
> time, for an average of 52.1 amps from the battery.
>
> Even though the number of amp-hours stays the same, when you add more
> batteries in series, you draw less amps from the batteries, so they last
> longer.
>
> -Morgan LaMoore
>
> On 8/18/07, joe <[hidden email]> wrote:
>>
>> Wait a minute, guys - as has been stated before, adding batteries will
>> NOT
>> necessarily give you more range! It will give you somewhat better
>> performance, all else being equal. The amp-hours remains the same for any
>> number of batteries connected in series, and the additional weight will
>> negate most of the benefit beyond a certain point.
>>
>> Batteries connected in parallel will give more range, batteries connected
>> in
>> series will boost performance.
>>
>> Joseph H. Strubhar
>>
>> Web: www.gremcoinc.com
>>
>> E-mail: [hidden email]
>> ----- Original Message -----
>> From: "Joseph T. " <[hidden email]>
>> To: "Electric Vehicle Discussion List" <[hidden email]>
>> Sent: Friday, August 17, 2007 10:06 PM
>> Subject: Re: [EVDL] battery help
>>
>>
>> > "I was really just looking for confirmation that adding two additional
>> > batteries to the voltsrabbit design would boost the range."
>> >
>> > Adding two batteries will definitely give you more range. If you'd
>> > like to mess around with different EV configurations you can go to
>> > evconvert.com for their EV calculator.
>> >
>> >
>> > On 8/17/07, John A. Evans - N0HJ <[hidden email]> wrote:
>> >> Thanks David and all,
>> >>
>> >>  I was really just looking for confirmation that adding two additional
>> >> batteries to the voltsrabbit design would boost the range.  Of course,
>> I
>> >> should know that I really need to be correct and explicit in my
>> >> terminology when I ask questions here.
>> >>
>> >> Thanks again,
>> >> John
>> >>
>> >> _______________________________________________
>> >> 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
>

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