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Discussion Starter #2
Evdave wrote:

> I have an E10.... 144 volt system, (12vdcx3banks)
>
> I need to do new batteries.....

One of the single biggest improvements you could make would be to
replace the 3 strings of small batteries with a single string of larger
capacity batteries. This would necessitate making up new battery cables
and you need to figure out the dimensions of your battery box(es) in
order to identify a replacement battery model that will fit.

Cor has reported good success replacing the pack in his S10 EV with AGMs
from Universal Battery
(<http://www.universalpowergroup.com/batteries/sla.aspx#AGM>). IIRC,
your E10 probably has 3 strings of 26Ah Hawkers, making up a 78Ah 144V
pack. So, from the Universal Battery catalog you would probably want to
look at models in the 75-110Ah ballpark (UB12750 - UB121100).

You might also have a look at the Discover Energy catalog
(<http://www.discover-energy.com/productsearch?page=10>). The 12V AGM
models such as the EV24A-A, EV27A-A, EV31A-A, EV30A, etc. are ones most
likely of interest.

Cheers,

Roger.

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Discussion Starter #3
I wouldn't mind changing the three strings to one big one, but I thought
the advantage to having 3 strings of smaller batteries was to increase
the available amps??? Is that not true? Currently, the batteries are
"DISCOVER" im at work and I don't have the model number, but when I
looked them up, I believe they were wheelchair batteries... Ill have to
look at the numbers... I tried to figure out how many Ahs I had
available and it didn't seem like much.



Db



-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of Roger Stockton
Sent: Monday, September 24, 2007 4:21 PM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Solectria battery question

Evdave wrote:

> I have an E10.... 144 volt system, (12vdcx3banks)
>
> I need to do new batteries.....

One of the single biggest improvements you could make would be to
replace the 3 strings of small batteries with a single string of larger
capacity batteries. This would necessitate making up new battery cables
and you need to figure out the dimensions of your battery box(es) in
order to identify a replacement battery model that will fit.

Cor has reported good success replacing the pack in his S10 EV with AGMs
from Universal Battery
(<http://www.universalpowergroup.com/batteries/sla.aspx#AGM>). IIRC,
your E10 probably has 3 strings of 26Ah Hawkers, making up a 78Ah 144V
pack. So, from the Universal Battery catalog you would probably want to
look at models in the 75-110Ah ballpark (UB12750 - UB121100).

You might also have a look at the Discover Energy catalog
(<http://www.discover-energy.com/productsearch?page=10>). The 12V AGM
models such as the EV24A-A, EV27A-A, EV31A-A, EV30A, etc. are ones most
likely of interest.

Cheers,

Roger.

_______________________________________________
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Discussion Starter #4
Evdave wrote:

> I wouldn't mind changing the three strings to one big one,
> but I thought the advantage to having 3 strings of smaller
> batteries was to increase the available amps??? Is that
> not true?

Not necessarily. 2 or 3 strings of small batteries can provide more
amps than one string of them would, but that does not necessarily mean
they will provide more amps than a single string of larger batteries.

Almost always, multiple strings are used because the builder wanted to
use a particular type/make of battery and needed more capacity than was
available from that maker. For instance, with Hawkers the largest
capacity AGM that is readily available is 42Ah (they list a 70Ah model,
but I've yet to see one or hear of anyone using it); if one wants to use
Hawkers for their high-current capability but want more than 42Ah (or
more than 70Ah), they might use a pair of strings of the 42Ah modules
for 84Ah. 3 strings of the 26Ah modules gives similar capacity, but
might fit into the available space better or the 26Ah modules might end
up cheaper than 2 strings of 42Ah's (at least when the truck was built),
etc.

Does your E10 have one motor controller or two? Typically the motor
controllers in Solectria vehicles are limited to less than 300A each, so
a pair could subject the pack to a pretty good load, but one would be a
pretty easy load for many different AGMs.

The downside to having multiple strings of small batteries is that it is
difficult to ensure that each string shares the load equally or that
each string gets an appropriate fraction of the charge current. A
single string of batteries is going to be more reliable and should last
longer (years, not distance per charge) if you use batteries that will
tolerate the loads you place on them and don't run them dead on each
outing. Using larger capacity batteries will allow you to travel
further on a charge, or to not run the batteries as low on your regular
trips such that they last longer before needing replacement.

If you have a pair of controllers subjecting the battery pack to peaks
approaching 600A, then you may need to stick with one of the few AGM
makes that are proven to hold up well in high current EV use. Something
like a single string of Optima D31's (about 75Ah, as I recall). From
the Odyssey (Hawker) lineup, something like the 68Ah PC1700 or 100Ah
PC2150 (<http://www.odysseybatteries.com/battery/pc2150.htm>) could be a
good choice.

Cheers,

Roger.

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Discussion Starter #5
Solectria put a fair bit of research - and a lot of cut and try - into
selecting the batteries for their EVs. In the end they settled on East Penn
gel batteries (design licensed from Sonnenschein). Along the way they had a
brief flirtation with Hawker Genesis batteries, which didn't work out so
well.

If your vehicle is fitted with Hawkers, it might be worth your while to
switch to East Penns. The catch is that it's more than a fitment issue.
You'll need to reprogram the charger or it'll destroy the new battery pack
in a matter of weeks. I don't know whether Azure can still reprogram the
older chargers - probably not.

Are you up for reprogramming the charger yourself? If you have a Brusa-
built NLG4 type charger (BC-3300, I think Solectia called them), it should
be fairly easy with Brusa's old DOS software and a laptop you can boot from
a DOS floppy. If it's an older BC-1000, you're probably stuck. In that
case you'll most likely have to buy a new charger and have it set up for
whatever batteries you choose.

If you currently have East Penn batteries (Deka Dominator gel) I'd recommend
replacing with the same type. They're pretty long-lived and reliable in
this application.

You might want to join the Solectria group on Yahoo :

http://autos.groups.yahoo.com/group/solectria_ev/

David Roden
EVDL Administrator
http://www.evdl.org/


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Discussion Starter #6
My system has 2 controllers... I think the max draw is 200 amp.... But
im guessing that is to each motor? So then wouldn't that be a total of
400 amps from the batteries?

Db



-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of Roger Stockton
Sent: Monday, September 24, 2007 5:42 PM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Solectria battery question


Evdave wrote:

> I wouldn't mind changing the three strings to one big one,
> but I thought the advantage to having 3 strings of smaller
> batteries was to increase the available amps??? Is that
> not true?

Not necessarily. 2 or 3 strings of small batteries can provide more
amps than one string of them would, but that does not necessarily mean
they will provide more amps than a single string of larger batteries.

Almost always, multiple strings are used because the builder wanted to
use a particular type/make of battery and needed more capacity than was
available from that maker. For instance, with Hawkers the largest
capacity AGM that is readily available is 42Ah (they list a 70Ah model,
but I've yet to see one or hear of anyone using it); if one wants to use
Hawkers for their high-current capability but want more than 42Ah (or
more than 70Ah), they might use a pair of strings of the 42Ah modules
for 84Ah. 3 strings of the 26Ah modules gives similar capacity, but
might fit into the available space better or the 26Ah modules might end
up cheaper than 2 strings of 42Ah's (at least when the truck was built),
etc.

Does your E10 have one motor controller or two? Typically the motor
controllers in Solectria vehicles are limited to less than 300A each, so
a pair could subject the pack to a pretty good load, but one would be a
pretty easy load for many different AGMs.

The downside to having multiple strings of small batteries is that it is
difficult to ensure that each string shares the load equally or that
each string gets an appropriate fraction of the charge current. A
single string of batteries is going to be more reliable and should last
longer (years, not distance per charge) if you use batteries that will
tolerate the loads you place on them and don't run them dead on each
outing. Using larger capacity batteries will allow you to travel
further on a charge, or to not run the batteries as low on your regular
trips such that they last longer before needing replacement.

If you have a pair of controllers subjecting the battery pack to peaks
approaching 600A, then you may need to stick with one of the few AGM
makes that are proven to hold up well in high current EV use. Something
like a single string of Optima D31's (about 75Ah, as I recall). From
the Odyssey (Hawker) lineup, something like the 68Ah PC1700 or 100Ah
PC2150 (<http://www.odysseybatteries.com/battery/pc2150.htm>) could be a
good choice.

Cheers,

Roger.

_______________________________________________
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_______________________________________________
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Discussion Starter #7
Yes, I have the nlg4 and I have the programing that I have been able to
hook up to my laptop and run it in a dosshell.... Im comfortable
programing it, but I don't know the proper settings.... So you are
recommending the east penns as a first choice? The current battery is a
DISCOVER battery, but I don't know what was in it previous to them....



-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of David Roden (Akron OH USA)
Sent: Monday, September 24, 2007 5:44 PM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Solectria battery question


Solectria put a fair bit of research - and a lot of cut and try - into
selecting the batteries for their EVs. In the end they settled on East
Penn
gel batteries (design licensed from Sonnenschein). Along the way they
had a
brief flirtation with Hawker Genesis batteries, which didn't work out so

well.

If your vehicle is fitted with Hawkers, it might be worth your while to
switch to East Penns. The catch is that it's more than a fitment issue.

You'll need to reprogram the charger or it'll destroy the new battery
pack
in a matter of weeks. I don't know whether Azure can still reprogram
the
older chargers - probably not.

Are you up for reprogramming the charger yourself? If you have a Brusa-
built NLG4 type charger (BC-3300, I think Solectia called them), it
should
be fairly easy with Brusa's old DOS software and a laptop you can boot
from
a DOS floppy. If it's an older BC-1000, you're probably stuck. In that

case you'll most likely have to buy a new charger and have it set up for

whatever batteries you choose.

If you currently have East Penn batteries (Deka Dominator gel) I'd
recommend
replacing with the same type. They're pretty long-lived and reliable in

this application.

You might want to join the Solectria group on Yahoo :

http://autos.groups.yahoo.com/group/solectria_ev/

David Roden
EVDL Administrator
http://www.evdl.org/


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


_______________________________________________
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Discussion Starter #8
EVdave

> My system has 2 controllers... I think the max draw is
> 200 amp.... But im guessing that is to each motor?
> So then wouldn't that be a total of 400 amps from the
> batteries?

Right.

I think this may be why Solectria went to Hawkers (AGMs) for the vehicle
instead of the DEKA gels that (as has been pointed out) worked so sell
for them in the (single controller) Forces.

Unless you went to a fairly large model of DEKA gel, I don't think a
single string of them would give you good life with 400A peak draws. I
wouldn't even bother unless you can fit at least an 8G31 (~98Ah) gel
string. Better still would be a string of their 6V or 8V (golf car)
gels, but odds are those will be too tall for your existing boxes.

Cheers,

Roger.

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Discussion Starter #9
On 27 Sep 2007 at 14:46, EVdave wrote:

> So you are
> recommending the east penns as a first choice?

I'd recommend them for Solectria EVs, yes. The problem is determining how
your charger is set up, to make sure that it'll play nice with those
batteries.

Unless I'm mistaken, Solectria completely abandoned Hawkers. They couldn't
ram enough current into them to make them charge right. They also pretty
much can't live without individual battery regulators.

The lower voltage Solectria trucks used dual controllers - but they also
used double battery strings. Some trucks were built with higher voltages,
but the effect is the same because the current required is lower. So, IMO
the East Penn batteries are indeed suitable for the application.

David Roden - Akron, Ohio, USA
EVDL Administrator

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EVDL Information: http://www.evdl.org/help/
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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/ .
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Discussion Starter #10
So how would I determine the correct charging parameters???

db

-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of David Roden
Sent: Thursday, September 27, 2007 7:40 PM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Solectria battery question


On 27 Sep 2007 at 14:46, EVdave wrote:

> So you are
> recommending the east penns as a first choice?

I'd recommend them for Solectria EVs, yes. The problem is determining
how
your charger is set up, to make sure that it'll play nice with those
batteries.

Unless I'm mistaken, Solectria completely abandoned Hawkers. They
couldn't
ram enough current into them to make them charge right. They also
pretty
much can't live without individual battery regulators.

The lower voltage Solectria trucks used dual controllers - but they also

used double battery strings. Some trucks were built with higher
voltages,
but the effect is the same because the current required is lower. So,
IMO
the East Penn batteries are indeed suitable for the application.

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/ .
= = = = = = = = = = = = = = = = = = = = = = = = = = = = =


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Discussion Starter #11
On 28 Sep 2007 at 10:18, EVdave wrote:

> So how would I determine the correct charging parameters???

Watch the voltage across the battery pack as it charges. In a typical case,
voltage should rise until it reaches about 14.1 to 14.3 volts per battery
(multiply this number the the quantity of batteries IN SERIES). For
example, if you have a 144 volt system, the battery should max out at
somewhere between 169.2 to 171.6 volts.

The voltage should hold about steady at that level for a few more hours
while the charging current falls.

I don't know whether it's completely typical - Solectria may have used
different algorithms at different times - but I have a description of an
East Penn 8G27 profile here which I think is one they used. It's a bit
unusual in that it doesn't use an IUI profile. Here's the outline :

1. Constant voltage at 14.1v per module until current falls below 4a

2. Constant current at 3a until an additional 8ah have been added

3. Float forever at 13.6v per module

The voltages are temperature compensated at -0.2% per deg C based on 30 deg
C.

There are a few other safety-related limitations such as battery
temperature, battery voltage, total kWh consumed, etc.

I would have used a constant current bulk phase and wouldn't have allowed
eternal float. However, I can't argue with the fact that Solectria Force
batteries seem to last a long time, presumably using this algorithm.

Anyway, to sum up, what you want to watch for is the maximum voltage across
the battery when it is charging. If it's in excess of 14.3 volts per
module, you'll need to have the charger reprogrammed before trying to use
gel batteries.

The only problem with judging it this way is that if your current battery
pack is 100% toast, it may never reach full voltage.

David Roden - Akron, Ohio, USA
EVDL Administrator

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EVDL Information: http://www.evdl.org/help/
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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/ .
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Discussion Starter #12
David Roden wrote:

> I don't know whether it's completely typical - Solectria may
> have used different algorithms at different times - but
> I have a description of an East Penn 8G27 profile here
> which I think is one they used.
> It's a bit unusual in that it doesn't use an IUI profile.
>
> Here's the outline :
>
> 1. Constant voltage at 14.1v per module until current falls
> below 4a
>
> 2. Constant current at 3a until an additional 8ah have been
> added
>
> 3. Float forever at 13.6v per module
>
> The voltages are temperature compensated at -0.2% per deg C
> based on 30 deg C.
>
> There are a few other safety-related limitations such as battery
> temperature, battery voltage, total kWh consumed, etc.
>
> I would have used a constant current bulk phase and wouldn't
> have allowed eternal float.

Actually, this *is* an IUI algorithm, they're just being sneaky about
how it is described.

If the charger applies 14.1V to a discharged battery, the battery will
typically try to draw an enormous current; more than the charger can
supply. So, the charger goes into current limit at whatever its max
current is until the battery comes up to the constant voltage setting.

This is a common format for describing an algorithm where the magnitude
of the bulk current is not a concern. However, the bulk current
should/must be limited when charging gels; Solectria may have met this
simple by ensuring that the charger(s) they used were incapable of
delivering a current higher than the 30A/100Ah C/20 specified by East
Penn/DEKA.

Cheers,

Roger.

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