# [EVDL] Brass for battery interconnects, how will it work?



## EVDL List (Jul 27, 2007)

> Christopher Zach wrote:
> > I'm currently trying to figure out how to make new interconnects for my
> > US Electricar Prizm. The new pack is made of 50 UB12-260's, which have
> > flag terminals instead of the older flat-top hawker terminals.
> ...


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## EVDL List (Jul 27, 2007)

Install these batteries in a battery case that is done like industrial 
batteries packs by the manufacturer.

I had install seperated 2 volt cells into a battery box that are space apart 
only at top by cutting 1/4 inch wide plastic strips and placing them between 
all the cells and sides of the container.

Make these a tight fit, so they do not slip down. Place them about 1/4 inch 
down below the top surface of the cells. Then you pour in a battery potting 
compound over these seperator strips to seal the batteries.

This is how some Exide 48 volt fork lift batteries pack are done. Instead 
of using the battery potting compound, I have use a black Lexan cauking 
compounds that works very good that you can get from Home Depot. Smooth out 
the cauking compound with a wet soapy plastic tool or a wet soapy finger.

Now as for links, we use large lead bars, that we welded on to the battery 
post. For ease of maintenance, you could use a flat copper bar of 3/16 to 
1/4 thick by 1 inch wide. Install a glue type heat srink over the this bar, 
except for the contact ends.

Just before you install this bar, polish up the contact area with a rotary 
steel brush and quickly install the bar before the copper turnishes.

After torqing the link using the stainless steel fasterners, cover the 
expose copper ends with a plastic tool hand dip which is also acid proof and 
can be use for battery connections. I use either the LokTite or Perfomix 
Plastic Dip compound that you can also get from Home Depot.

Roland




----- Original Message ----- 
From: "Christopher Zach" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Saturday, October 18, 2008 1:06 PM
Subject: [EVDL] Brass for battery interconnects, how will it work?


> I'm currently trying to figure out how to make new interconnects for my
> US Electricar Prizm. The new pack is made of 50 UB12-260's, which have
> flag terminals instead of the older flat-top hawker terminals.
>
> The problem is how to connect the batteries to each other. The space for
> the interconnect is 1/2 inch wide and tall square by just under 1 inch
> long between batteries. Very little room for error.
>
> The car will pull 100a per string (two strings) under full power, so
> whatever I use will have to handle 100a with possible peaks to 200a for
> a few seconds. I can't use cable as there is not enough room for
>
> I thought about using copper bar, however the thinnest 1/2 bar I can get
> is far too thick for me to bend accurately.
>
> My other thought is to go with 1/2 square brass stock cut into 1 inch
> lengths, then drill holes in the end, tap for the 8mm bolts that the
> Hawkers used, and use them solid between the batteries. My questions are:
>
> 1) Will this work electrically; is brass low enough of resistance?
> 2) Am I going to run into trouble with the battery posts flexing (the
> batteries are very snugly packed with plastic separators between each
> battery with squares cut out in the center so the battery can bulge as
> it gets old)
> 3) Anyone else got another idea?
>
> As a bonus, I could solder the zener regulator diode/rings to the top
> and bottom of each interconnect, resulting in a really great heat sink
> between the batteries.
>
> Thoughts? Any better ideas? Help 
>
> Chris
>
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> 

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## EVDL List (Jul 27, 2007)

Just an idea.
Cast them in lead. Cast your 8mm nuts in square lead molds. Use a wood dowl 
threded into the nuts to hold and place them centered. I figure it wouldn't 
be that hard to make a mold out of angle iron with a notch cut out for the 
wood dowl.

I used to help my uncle cast lead shot for ammo back in the late 80's. You 
can melt small batches easily in a small cast iron pot with a propane torch.

Do your own research on working with lead but basically lead isn't 
dangerious (lead poisning) unless you ingest it. Wash your cloths and hands 
afterwards and don't eat or drink anything during. Basicall don't put you 
hands in your mouth untill you wash them. Also make sure your tools and 
molds are dry. Water in molten lead will spray hot lead everwhere! Don't let 
sweat drop in etc.

Stub






> Christopher Zach wrote:
> > I'm currently trying to figure out how to make new interconnects for
> > my US Electricar Prizm. The new pack is made of 50 UB12-260's, which
> > have flag terminals instead of the older flat-top hawker terminals.
> ...


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## EVDL List (Jul 27, 2007)

If you search the archives, you should find sources for 1/8" and 1/4" copper
barstock -- I can't remember where I got mine off the top of my head right
now, but I do remember sending it to the EVDL earlier this spring.

Z



> Chris Stephens <[email protected]> wrote:
> 
> >
> > Just an idea.
> ...


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## EVDL List (Jul 27, 2007)

> Zeke Yewdall wrote:
> > If you search the archives, you should find sources for 1/8" and 1/4" copper
> > barstock -- I can't remember where I got mine off the top of my head right
> > now, but I do remember sending it to the EVDL earlier this spring.
> ...


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## EVDL List (Jul 27, 2007)

> Zeke Yewdall wrote:
> > If you search the archives, you should find sources for 1/8" and 1/4" copper
> > barstock -- I can't remember where I got mine off the top of my head right
> > now, but I do remember sending it to the EVDL earlier this spring.
> ...


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## EVDL List (Jul 27, 2007)

> Josh Wyatt wrote:
> > It's hard for me to visualize your setup, but if 1/2 by 1/2 by 1 inch square brass would work for you, and you intend to drill and tap it for #8 bolts, how about 1/2 by 1/2 by 1 inch solid aluminum? Aluminum is MUCH better electrically than brass.
> 
> Hm, that could be interesting. Can aluminum hold a thread? I'd probably
> ...


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## EVDL List (Jul 27, 2007)

> Roland Wiench wrote:
> > Install these batteries in a battery case that is done like industrial
> > batteries packs by the manufacturer.
> 
> ...


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## EVDL List (Jul 27, 2007)

Looks like Stormcopper.com is where I bought mine. 0.125" thick x 0.75"
wide by 6 foot long copper stock.

Z



> Christopher Zach <[email protected]>wrote:
> 
> > Roland Wiench wrote:
> > > Install these batteries in a battery case that is done like industrial
> ...


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## EVDL List (Jul 27, 2007)

> Josh Wyatt wrote:
> >
> > how about 1/2 by 1/2 by 1 inch solid aluminum? Aluminum is MUCH better
> > electrically than brass.
> ...


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## EVDL List (Jul 27, 2007)

> Zeke Yewdall wrote:
> > Looks like Stormcopper.com is where I bought mine. 0.125" thick x 0.75"
> > wide by 6 foot long copper stock.
> 
> ...


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## EVDL List (Jul 27, 2007)

> Christopher Zach wrote:
> > Josh Wyatt wrote:
> >> It's hard for me to visualize your setup, but if 1/2 by 1/2 by 1 inch square brass would work for you, and you intend to drill and tap it for #8 bolts, how about 1/2 by 1/2 by 1 inch solid aluminum? Aluminum is MUCH better electrically than brass.
> >
> ...


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## EVDL List (Jul 27, 2007)

> Josh Wyatt wrote:
> > I tap aluminum all the time for 6-32 threads, by hand. I have not tried using a machine tap. I also have not tried larger sizes (such as 8-24). Not sure of how much torque can be administered without stripping the threads, but the larger the tapped hole, the more torque you can use.
> 
> I'll be tapping and drilling these by hand as well. I think I'll go out
> ...


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## EVDL List (Jul 27, 2007)

> Christopher Zach wrote:
> > I'm currently trying to figure out how to make new interconnects for my
> > US Electricar Prizm. The new pack is made of 50 UB12-260's, which have
> > flag terminals instead of the older flat-top hawker terminals.
> ...


----------



## EVDL List (Jul 27, 2007)

You should use a lubricant for tapping aluminum like Tap-Magic. For 
strong threads in aluminum use a helicoil.

- SteveS



> Josh Wyatt wrote:
> > Christopher Zach wrote:
> >>
> 
> ...


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## EVDL List (Jul 27, 2007)

Please, guys, do yourself a favor and use copper ONLY; aluminum, steel, or 
brass just isn't going to cut it for battery interconnects, even for low 
currents. Aluminum is too soft and has too much corrosion possibilities, 
brass isn't conductive enough (red brass might work for low currents, but I 
would never use it), and steel is a very good resistor, and will heat up!

Joseph H. Strubhar

Web: www.gremcoinc.com

E-mail: [email protected]
----- Original Message ----- 
From: "Christopher Zach" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Saturday, October 18, 2008 6:38 PM
Subject: Re: [EVDL] Brass for battery interconnects, how will it work?




> > Josh Wyatt wrote:
> >> I tap aluminum all the time for 6-32 threads, by hand. I have not tried
> >> using a machine tap. I also have not tried larger sizes (such as 8-24).
> >> Not sure of how much torque can be administered without stripping the
> ...


----------



## EVDL List (Jul 27, 2007)

Actually after following this I can see it needs more study. It all revolves
around dimensions. If the aluminum bar is 4 times the area of the copper bar
will it indeed not be a better conductor that the copper bar? Along with its
ability to be tapped easier and hold a bolt better the only problem I see
becomes the corrosion problem. Proper anticorrosion product use might negate
this. One more thing to consider is the softness of aluminum. It is
certainly not as soft as the lead you are attaching it to. I actually see a
possibility here to use 1" by 1" aluminum bar to connect battery to battery.

Mark Grasser
Eliot, ME

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf
Of joe
Sent: Sunday, October 19, 2008 9:39 AM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Brass for battery interconnects, how will it work?

Please, guys, do yourself a favor and use copper ONLY; aluminum, steel, or 
brass just isn't going to cut it for battery interconnects, even for low 
currents. Aluminum is too soft and has too much corrosion possibilities, 
brass isn't conductive enough (red brass might work for low currents, but I 
would never use it), and steel is a very good resistor, and will heat up!

Joseph H. Strubhar

Web: www.gremcoinc.com

E-mail: [email protected]
----- Original Message ----- 
From: "Christopher Zach" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Saturday, October 18, 2008 6:38 PM
Subject: Re: [EVDL] Brass for battery interconnects, how will it work?




> > Josh Wyatt wrote:
> >> I tap aluminum all the time for 6-32 threads, by hand. I have not tried
> >> using a machine tap. I also have not tried larger sizes (such as 8-24).
> >> Not sure of how much torque can be administered without stripping the
> ...


----------



## EVDL List (Jul 27, 2007)

I am coming in late to this, is there room above the batteries?
why not a short vertical loop of either 2/0 cable or if it is really 
tight the braided ground strap rolled and crimped into lugs.

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## EVDL List (Jul 27, 2007)

Chris, 

You need these. http://inertext.homeunix.com/flatlug.jpg



http://www.nabble.com/file/p20056901/flatlug.jpg 







> Christopher Zach wrote:
> >
> >
> > 3) Anyone else got another idea?
> ...


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## EVDL List (Jul 27, 2007)

> gottdi wrote:
> > Chris,
> >
> > You need these. http://inertext.homeunix.com/flatlug.jpg
> ...


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## EVDL List (Jul 27, 2007)

> Jeff Shanab wrote:
> > I am coming in late to this, is there room above the batteries?
> > why not a short vertical loop of either 2/0 cable or if it is really
> > tight the braided ground strap rolled and crimped into lugs.
> ...


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## EVDL List (Jul 27, 2007)

6061 or 6063 aluminium alloys don't corrode like other al alloys. 6061 is
common
and cheap. It's used on a lot of truck bodies/trailers and even on salt
water
boats. In T6 it will easily hold a thread and is quite a bit stronger than
brass or copper.

The down side is that if you expose it to the acid fumes it might go away 
faster. A bit of that plastic tool coat would fix that.

Dave

-----Original Message-----

Actually after following this I can see it needs more study. It all revolves
around dimensions. If the aluminum bar is 4 times the area of the copper bar
will it indeed not be a better conductor that the copper bar? Along with its
ability to be tapped easier and hold a bolt better the only problem I see
becomes the corrosion problem. Proper anticorrosion product use might negate
this. One more thing to consider is the softness of aluminum. It is
certainly not as soft as the lead you are attaching it to. I actually see a
possibility here to use 1" by 1" aluminum bar to connect battery to battery.

Mark Grasser
Eliot, ME

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf
Of joe
Sent: Sunday, October 19, 2008 9:39 AM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Brass for battery interconnects, how will it work?

Please, guys, do yourself a favor and use copper ONLY; aluminum, steel, or 
brass just isn't going to cut it for battery interconnects, even for low 
currents. Aluminum is too soft and has too much corrosion possibilities, 
brass isn't conductive enough (red brass might work for low currents, but I 
would never use it), and steel is a very good resistor, and will heat up!

Joseph H. Strubhar

Web: www.gremcoinc.com

E-mail: [email protected]
----- Original Message ----- 
From: "Christopher Zach" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Saturday, October 18, 2008 6:38 PM
Subject: Re: [EVDL] Brass for battery interconnects, how will it work?




> > Josh Wyatt wrote:
> >> I tap aluminum all the time for 6-32 threads, by hand. I have not tried
> >> using a machine tap. I also have not tried larger sizes (such as 8-24).
> >> Not sure of how much torque can be administered without stripping the
> ...


----------



## EVDL List (Jul 27, 2007)

> Lee Hart wrote:
> > You don't want a rigid buss bar between batteries. The batteries always
> > move slightly due to temperature, braking, cornering, etc. Rigid bars
> > put all the stress on the terminals, which will crack and leak.
> ...


----------



## EVDL List (Jul 27, 2007)

> Joseph H. Strubhar wrote:
> > Please, guys, do yourself a favor and use copper ONLY; aluminum, steel,
> > or brass just isn't going to cut it for battery interconnects, even
> > for low currents.
> ...


----------



## EVDL List (Jul 27, 2007)

> Christopher Zach wrote:
> > gottdi wrote:
> >> Chris,
> >>
> ...


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## EVDL List (Jul 27, 2007)

From: Christopher Zach <[email protected]>
> Lee: You're probably the smartest person in the universe, so I will
> listen to you (as well as the rest of the list)...

Hardly! The smartest person is apparently Joe the Plumber (according to the two US Presidential candidates).

> So instead of spending $50 for a sheet of copper, I went down to Home 
> Despot, paid $10.00 and got an 8 foot length of 1/2 copper pipe.
> Crushing it with the vise does two things:
>1) Makes it 1 inch wide, too wide to use (I can go a max of 1/2 inch)
>2) Causes cracks to appear on the 4 sides (oddly enough).

> Now should I use heat before bending the copper, or can I just bend it?

It cracked because it's been hardened. There are two types of copper tubing; rigid and flexible. You got the rigid one. The flexible stuff comes on a spool, and bends easily in your bare hands.

For electrical connections, you want soft copper. It has less resistance, and bends easily. My suggestion would be to try places that have soft sheet copper, such as flashing for roofing or at hobby and craft stores.

If you already have the hardened copper, you can anneal it with a propane torch. Heat it up, and let it cool slowly. I don't know the times and temperatures; perhaps someone else has that data, or you can find it somewhere online.

--
Those who say it cannot be done should not interrupt the one who is
doing it. -- Chinese proverb
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart-at-earthlink.net

_______________________________________________
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Usage guidelines: http://evdl.org/help/index.html#conv
Archives: http://evdl.org/archive/
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## EVDL List (Jul 27, 2007)

> Lee Hart wrote:
> > It cracked because it's been hardened. There are two types of copper tubing; rigid and flexible. You got the rigid one. The flexible stuff comes on a spool, and bends easily in your bare hands.
> 
> Hm. Then I wonder if the copper bar stock from onlinemetals is hardened
> ...


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## EVDL List (Jul 27, 2007)

Use the copper tubing instead of pipe, or heat the pipe to anneal it (make 
it softer).

Personally, I wouldn't use copper pipe at all - but it is better than brass 
or aluminum.

Joseph H. Strubhar

Web: www.gremcoinc.com

E-mail: [email protected]
----- Original Message ----- 
From: "Christopher Zach" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Sunday, October 19, 2008 5:08 PM
Subject: Re: [EVDL] Brass for battery interconnects, how will it work?




> > Lee Hart wrote:
> >> You don't want a rigid buss bar between batteries. The batteries always
> >> move slightly due to temperature, braking, cornering, etc. Rigid bars
> >> put all the stress on the terminals, which will crack and leak.
> ...


----------



## EVDL List (Jul 27, 2007)

Chris, I've just rigged up a temporary set of batteries in my
3-wheeler, using the little Hawkers with M6 upright posts. I used
1/2" x (I think) 1/16th transformer winding. I used a sander to take
the varnish off at the contacts.
I'll post a picture up later but if you can get hold of that type of
copper strip, it should be no problem to bend it as needed.



> Christopher Zach <[email protected]> wrote:
> > I'm currently trying to figure out how to make new interconnects for my
> > US Electricar Prizm. The new pack is made of 50 UB12-260's, which have
> > flag terminals instead of the older flat-top hawker terminals.
> ...


----------



## EVDL List (Jul 27, 2007)

Chris,

When we were running Cyclon batteries, we built interconnects like these. 
Step by Step instruction here: http://www.proev.com/WHistPgs/Hist0011.htm


Cliff
www.ProEV.com




> > gottdi wrote:
> >> Chris,
> >>
> >> You need these. http://inertext.homeunix.com/flatlug.jpg
> ...


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## EVDL List (Jul 27, 2007)

> Mark Grasser wrote:
> > Actually after following this I can see it needs more study. It all
> > revolves around dimensions. If the aluminum bar is 4 times the area
> > of the copper bar will it indeed not be a better conductor that the
> ...


----------



## EVDL List (Jul 27, 2007)

As promised, here's a picture of the copper strip I used. You should
be able to get this from any (large) motor and transformer winding
place.

http://farm4.static.flickr.com/3009/2959266942_5a89e3b4b7_b.jpg

Cliff's braided strap seems like a better idea to be honest, as it
allows for more movement without stressing the terminals too much.

You can also see a Lee Hart Zener Reg in that picture 

Regards
Evan




> Evan Tuer <[email protected]> wrote:
> > Chris, I've just rigged up a temporary set of batteries in my
> > 3-wheeler, using the little Hawkers with M6 upright posts. I used
> > 1/2" x (I think) 1/16th transformer winding. I used a sander to take
> ...


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## EVDL List (Jul 27, 2007)

Copper pipe is the worst copper for electrical applications, It is 
partially hardened just by the impurities in it. It is still more 
conductive than aluminum or brass, but if the runs were long, I would 
cringe.

_______________________________________________
General EVDL support: http://evdl.org/help/
Usage guidelines: http://evdl.org/help/index.html#conv
Archives: http://evdl.org/archive/
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