# [EVDL] Poor battery connections



## EVDL List (Jul 27, 2007)

Hello Al,

You may have gotten shrink back, meaning that you install new battery clamps 
on a lead post, that has been pre clean with one of those battery post 
cleaners, the battery clamp is setting on the high spots of all these lead 
post scratches and when you put on a initial load, these lead surface will 
melt back some.

In installing new battery clamps which should be a plated brass type, torque 
them to the specifications as call for in the Trojan maintenance WEB site. 
I think they are about 75 in.lbs.

Drive the EV only drawing a maximum of 200 to 300 amps for 5 miles and 
recheck the torque rating again. You will find it will lose about 5 in.lbs. 
the first five miles. Re-torque and then check again in the next 10 miles, 
re-torque as needed and re-torque at 20 miles,

You will the battery clamps will stable out by then. Do a check on some of 
the connections at a 100 miles, you then can calculated when you should do 
the next re-torque of the battery connections.

Its best to get a good torque wrench in the 1/4 inch size, and slip a foam 
pipe insulation over the handles after you set and lock it in.

The Trojan WEB site will give you a minimum and a maximum torque rating on 
the type of battery connections and posts are use.

One method I use to get more contact are on a battery clamp, is to set the 
clamp all the way down pressing against the offset battery base bars. 
Therefore the bottom of the battery clamp is increasing the contact area.

If you have post with a top stud, and if the battery clamp is lower than the 
top of the post, I installed a short piece of stainless steel tubing that I 
cut off a length of 3/4 I.D. tubing. Place it on top of the battery clamp 
so it is just about flush with the top of the battery post. Install a 
stainless steel washer, lock washer and nut which put additional pressure of 
the battery clamp down on to the lead base.

I then tighten the battery clamp to about 40 inch pounds or just hand 
tighten it, then tighten the top stud nut to 75 inch pounds which presses 
the battery clamp down on the base, then tighten the battery clamp to 75 
inch pounds, and finish up with 100 inch pounds with the top stud nut.

There was a battery clamp company back in the 70's that made EV battery 
links, that did this type of installation. They were a solid taper brass 
connections that had a cable molded into this connection. These type of 
battery connection was cover with a fuse on red plastic cover at one end and 
a black plastic cover at the other end of the link.

They slip over the taper post with a stud on top which came through the top. 
It has a O-ring on the bottom which seals the bottom connection. The nut 
was the only fastener use on these types of connections. The taper sides of 
this connection put a side force on the battery post which also puts a 
internal pressure of the in bedded stud, that can with stand 10 foot pounds. 
Not 100 inch pounds.

I try to find these type of battery connections, and do not see them any 
where. Back in the 70's these units cost about $20.00 a link, while the 
battery cost about $30.00.

I cannot make them in my machine shop for that cost.

I did this type of battery connection back in 2002, did the checks, and now 
only check them about once a year. I am still running the same batteries 
and battery clamps today.

Roland


----- Original Message ----- 
From: "Al" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Wednesday, September 19, 2007 8:55 PM
Subject: [EVDL] Poor battery connections


> You would think by now that there would be a standardized reliable way to
> get a good high current connection to a lead acid battery.
> When I looked at the standard battery lug for use with Trojan universal
> posts, I notice the actual contact area is pretty small.
> I decided to use the automotive tapered post type connector assuming it
> would have alot more contact area. Apparently they do not..
> I noticed my pack voltage dropping more than usual under load. After a 
> short
> trip I checked the connections and sure enough, they ranged
> from warm to downright hot! I pulled one connection and found that even
> though it was tight and clean, it had been arcing in between the post
> and the inside of the connector where it could not be seen. So, what type 
> of
> connector are the guys pulling 1000 amps using?
>
> Al
>
> _______________________________________________
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> 

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## EVDL List (Jul 27, 2007)

Hi Al,

I run those same tapered automotive post connections up to 1500 battery amps
without any problems on Joule Injected. If you're not using ones from
QuickCable, I would highly recommend them. The taper fits the post perfectly
and the clamp is greater in height for increased surface area.

The presence of arcing internally indicates to me that there is not good
surface contact between the post and clamp. It also suggests that there
might be some insulating coating on at least some of the surface of the post
or the clamp. Did you use a terminal brush for the post and the clamp before
attaching them?

Matt Graham
http://www.jouleinjected.com


-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf
Of Al
Sent: Wednesday, September 19, 2007 10:55 PM
To: Electric Vehicle Discussion List
Subject: [EVDL] Poor battery connections

You would think by now that there would be a standardized reliable way to 
get a good high current connection to a lead acid battery.
When I looked at the standard battery lug for use with Trojan universal 
posts, I notice the actual contact area is pretty small.
I decided to use the automotive tapered post type connector assuming it 
would have alot more contact area. Apparently they do not..
I noticed my pack voltage dropping more than usual under load. After a short

trip I checked the connections and sure enough, they ranged
from warm to downright hot! I pulled one connection and found that even 
though it was tight and clean, it had been arcing in between the post
and the inside of the connector where it could not be seen. So, what type of

connector are the guys pulling 1000 amps using?

Al 

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## EVDL List (Jul 27, 2007)

> Al wrote:
> > You would think by now that there would be a standardized reliable
> > way to get a good high current connection to a lead acid battery.
> 
> ...


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## EVDL List (Jul 27, 2007)

> Al wrote:
> 
> > When I looked at the standard battery lug for use with Trojan
> > universal posts, I notice the actual contact area is pretty small.
> ...


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## EVDL List (Jul 27, 2007)

This might be a good time to mention my recent experience while connecting T125 Trojan's with universal terminals. The UT's have a flat on each side, one accepts the bolt head and the other is for the battery lug to land on. I had to grind a bit off the bottom of each lug as there was interference between the radius of the UT flat and the outside edge of the lug. It wasn't obvious unless you looked carefully but the contact area would have been greatly reduced as the interference would not allow complete contact.








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## EVDL List (Jul 27, 2007)

Don't know if they pull 1000 amps, but I've always like Stinger (car audio)
terminals...

http://stingerelectronics.com/index.asp

Tyler
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## EVDL List (Jul 27, 2007)

> Tyler wrote:
> > Don't know if they pull 1000 amps, but I've always like Stinger (car audio)
> > terminals...
> >
> ...


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## EVDL List (Jul 27, 2007)

> Lee Hart wrote:
> 
> > Tyler wrote:
> > > Don't know if they pull 1000 amps, but I've always like
> ...


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## EVDL List (Jul 27, 2007)

These type of gold plated battery connectors were listed at about $10.00 
each from Sound Pro. The electrical mark up is about 100% from the factory 
to the wholesaler and to the retainer. So go figure.

When I was in the electrical business, the mark up was about 50% for one 
item, if when we purchase a truck load that was deliver to the job site, the 
local wholesaler would get about 2 to 5% over factory cost depending how 
they bid the job.

Roland


----- Original Message ----- 
From: "Roger Stockton" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Friday, September 21, 2007 11:51 AM
Subject: Re: [EVDL] Poor battery connections




> > Lee Hart wrote:
> >
> > > Tyler wrote:
> > > > Don't know if they pull 1000 amps, but I've always like
> ...


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## EVDL List (Jul 27, 2007)

Yes, I forgot to mention they are not cheep!

There are some that take 1/0 cable, as wells as positive and negative pairs,
not just universals, of course they're over $35 each!!!!! Oh well, we can't
have it all right!

Tyler
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## EVDL List (Jul 27, 2007)

[No message]


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## EVDL List (Jul 27, 2007)

[No message]


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## EVDL List (Jul 27, 2007)

[No message]


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## EVDL List (Jul 27, 2007)

> Roy LeMeur wrote:
> > Gold is soft.
> > Um... gold doesn't corrode. Ever.
> > Even at the bottom of the ocean for hundreds of years.
> ...


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## EVDL List (Jul 27, 2007)

Gold does not promote the corrosion of adjacent metals.

However, as you say gold platings are so thin they can certainly corrode
through the pinholes in a harsh environment. They last for years and
years in a PC inside a room where bare copper would tarnish quickly, but
they can't withstand everything.

Gold plating is prone to diffusion, especially against copper. 
Molecular diffusion is an odd process where even though it's a solid the
atoms are mobile and tend to mix up into an alloy. Gold atoms actually
migrate into copper and brass. Current is not required, put a thin gold
plate on copper, put it on a shelf, and some time later the surface is a
very low-carat gold-copper alloy with no corrosion-preventative
properties. Platers use a barrier layer, typically a thin layer of
nickel plate, to stop diffusion as well as prevent corrosion of the
underlying copper/brass through pores in the gold. But even with a gold
plated terminal plated with a proper barrier layer, migration will occur
into an unplated copper stud if they're bolted together. Elevated
temperatures will accelerate the migration. I don't know how fast gold
diffuses into a lead battery terminal though.

Danny

----- Original Message -----
From: Lee Hart <[email protected]>
Date: Sunday, September 30, 2007 11:03 am
Subject: Re: [EVDL] Poor battery connections
To: Electric Vehicle Discussion List <[email protected]>



> > Roy LeMeur wrote:
> > > Gold is soft.
> > > Um... gold doesn't corrode. Ever.
> > > Even at the bottom of the ocean for hundreds of years.
> ...


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