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Discussion Starter #1
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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Discussion Starter #2
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
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>

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Discussion Starter #3
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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Discussion Starter #4
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.

There is! It's a welded connection. This is how the connections between
cells are made inside the battery, and how industrial batteries are
jumpered together.

Basically, you use a lead or lead-coated terminal or busbar. Place it on
the lead post of the battery, and quickly heat it with a torch so the
lead melts and flows together. Done right, it is very fast and reliable.

Obviously, it is intended to be permanent -- you won't cut it until the
battery is bad and needs replacement anyway.

> I decided to use the automotive tapered post type connector assuming
> it would have a lot more contact area. Apparently they do not.

There are *large* variations in quality and performance in automotive
post connectors. Most are cheap and of low quality, intended for mass
produced consumer products like automotive starting batteries, where
high currents are only drawn for a few seconds.

The worse of these seems to be the "emergency terminal", which is a cast
lead terminal with a bolt to tighten it around the post, and two more
bolts and a steel clamp to pinch a bare wire into a slot in the other end.

The best type are made of solid copper, tin or lead plated. The wire
crimps in with a large crimper.
--
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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Discussion Starter #5
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.
> I decided to use the automotive tapered post type connector
> assuming it would have alot more contact area. Apparently
> they do not..

Which type of post does your battery have? Most likely it is the LPT
style, as I believe that is now the most common standard on GC
batteries:

<http://www.trojan-battery.com/Products/TerminalsDiagram.aspx>

The portion of the terminal that looks like a tapered automotive post
terminal is much shorter than it needs to be, and I'm not even sure that
it is tapered properly to fit standard battery clamps properly (standard
automotive posts are tapered, and are different sizes for the positive
and negative posts).

The universal posts (UT), are full height tapered posts with a through
hole and flats on the sides to allow lugs to be bolted to their sides;
this doesn't sound like what you have.

> So, what type of connector are the guys pulling 1000 amps using?

Standard automotive posts; AP on the Trojan battery types page. Trojan
states they are available on their flooded GC batteries, though you may
have difficulty getting a loacl distributor to supply you batteries with
them (probably special order).

The L terminal (LT) is another popular option on floodeds in EV use as
it offers lots of contact area for the lug and uses a through bolt to
secure the lug to the termainal.

Some of the high-performance AGMs such as Hawker/Odyssey typically come
with the threaded insert ("button", or BTN on the Trojan page) type of
terminal, and this is also good for high currents. The button terminal
differs from the threaded posts on flooded GC batteries in that it is
not a lead post and so the bolt can be tightened securely without fear
of lead creep and loosening over time (of course, the bolt is typically
6mm (about 1/4") vs the 5/16" or 3/8" threaded studs commonly on
floodeds.

Regardless of the type of terminal on the battery, it is important to
use good quality terminals on your cables. This is probably more so
with the automotive clamps than with lugs. I believe the benchmark is
probably the MagnaLugs, such as are sold by EV suppliers such as EV
Parts. Both the lug and clamp type are solid copper and crimp securely
to the cables and mate properly with the battery terminals.

If you've got the LPT type terminals on your batteries, your best option
may be to switch your cables to the lug type connectors and bolt them
down securely using Belleville spring washers under the nuts to keep
pressure applied as the connection loosens over time. Check them for
tightness periodically.

Something you might try if you don't want to remake your cables is to
tighten the clamps securely to the stubby posts and then use a flat
washer, lock washer and nut on the threaded post to apply downward
pressure on the battery clamp as well.

Cheers,

Roger.

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Discussion Starter #6
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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Discussion Starter #7
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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Discussion Starter #8
Tyler wrote:
> Don't know if they pull 1000 amps, but I've always like Stinger (car audio)
> terminals...
>
> http://stingerelectronics.com/index.asp

This stuff looks like all show, with no actual performance data at all.
I suspect you would find ridiculously high prices. Whether they actually
work could only be determined by actual test. Caveat emptor.

--
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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Discussion Starter #9
Lee Hart wrote:

> Tyler wrote:
> > Don't know if they pull 1000 amps, but I've always like
> > Stinger (car audio) terminals...
> >
> > http://stingerelectronics.com/index.asp
>
> This stuff looks like all show, with no actual performance
> data at all. I suspect you would find ridiculously high
> prices. Whether they actually work could only be determined
> by actual test. Caveat emptor.

In all fairness, I haven't seen any performance data for the
well-respected MagnaLug or QuickCable terminals commonly used by EVers
either ;^>

I've no doubt one might pay a premium for the good looks of these audio
connectors, but I see two signs that they probably wouldn't be a good
choice for EV use: first, most EVs able to draw 1000A use 1/0 or 2/0
cables but these connectors accept a maximum of 4 or 6ga, and secondly,
these terminals are advertised as fitting either positive or negative
posts, and since positive and negative posts are different sizes this
usually means they fit neither particularly well.

I believe I have seen some similar style car audio terminals that did
accept at least 1/0, and which may have been available in positive and
negative models, but I can't find them at the moment. I thought they
were from Lightning Audio (and maybe they were, it has been a few years
since I considered them), but Lightning Audio's site doesn't seem to
list any battery terminals these days.

I wouldn't automatically rule out the use of car audio type terminals if
you want to dress up batteries that are readily visible to the public;
John Wayland used car audio wire and connectors on the batteries in Blue
Meanie with success. However, as Lee suggests, caveat emptor: use
connectors that others have already proven work in EVs or test them
yourself, don't assume they will work as well as they look!

Cheers,

Roger.

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Discussion Starter #10
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
> > > Stinger (car audio) terminals...
> > >
> > > http://stingerelectronics.com/index.asp
> >
> > This stuff looks like all show, with no actual performance
> > data at all. I suspect you would find ridiculously high
> > prices. Whether they actually work could only be determined
> > by actual test. Caveat emptor.
>
> In all fairness, I haven't seen any performance data for the
> well-respected MagnaLug or QuickCable terminals commonly used by EVers
> either ;^>
>
> I've no doubt one might pay a premium for the good looks of these audio
> connectors, but I see two signs that they probably wouldn't be a good
> choice for EV use: first, most EVs able to draw 1000A use 1/0 or 2/0
> cables but these connectors accept a maximum of 4 or 6ga, and secondly,
> these terminals are advertised as fitting either positive or negative
> posts, and since positive and negative posts are different sizes this
> usually means they fit neither particularly well.
>
> I believe I have seen some similar style car audio terminals that did
> accept at least 1/0, and which may have been available in positive and
> negative models, but I can't find them at the moment. I thought they
> were from Lightning Audio (and maybe they were, it has been a few years
> since I considered them), but Lightning Audio's site doesn't seem to
> list any battery terminals these days.
>
> I wouldn't automatically rule out the use of car audio type terminals if
> you want to dress up batteries that are readily visible to the public;
> John Wayland used car audio wire and connectors on the batteries in Blue
> Meanie with success. However, as Lee suggests, caveat emptor: use
> connectors that others have already proven work in EVs or test them
> yourself, don't assume they will work as well as they look!
>
> Cheers,
>
> Roger.
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>

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Discussion Starter #11
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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Discussion Starter #15
Roy LeMeur wrote:
> Gold is soft.
> Um... gold doesn't corrode. Ever.
> Even at the bottom of the ocean for hundreds of years.

The gold plating on these connectors is just cosmetic (for looks). It is
microscopically thin; like 10 microinches. The problem with such thin
coatings is that they are porous (full of holes).

Gold is a noble metal. It doesn't corrode because it causes whatever
other metal is in contact with it to corrode instead. When you make an
electrical connection with gold on one side and something else on the
other, the other metal corrodes and you *still* get a bad connection.

An electrical quality gold plated connection will gold-plate BOTH sides
of the connector with at least 30-50 microinches of gold. This avoids
the dissimilar metals and the porosity problems.
--
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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Discussion Starter #16
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.
>
> The gold plating on these connectors is just cosmetic (for looks).
> It is
> microscopically thin; like 10 microinches. The problem with such
> thin
> coatings is that they are porous (full of holes).
>
> Gold is a noble metal. It doesn't corrode because it causes
> whatever
> other metal is in contact with it to corrode instead. When you make
> an
> electrical connection with gold on one side and something else on
> the
> other, the other metal corrodes and you *still* get a bad connection.
>
> An electrical quality gold plated connection will gold-plate BOTH
> sides
> of the connector with at least 30-50 microinches of gold. This
> avoids
> the dissimilar metals and the porosity problems.
> --
> 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
>

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