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#1 Battery terminal won't tighten
Posted: Sun Jan 03, 2016 11:31 pm
by andrewh
Simple problem. The screw terminal will not tighten the round earth lead firmly to the battery. Anyone got a fix short of changing the battery or the lead?
#2
Posted: Mon Jan 04, 2016 3:56 am
by 38E
Is it because you've reversed the battery polarity? If so, one connection will be too loose. I had to use a different type of clamp for the earth on mine.
Cost me a deduction in concours, though.

#3
Posted: Mon Jan 04, 2016 6:52 am
by abowie
Make a sleeve out of a bit of lead sheet. Wrap it around the terminal.
#4
Posted: Mon Jan 04, 2016 10:23 am
by MarekH
The positive and negative battery terminals are different diameters and the leads match them with different diameter clamps. If you mix them up or "adapt" one, then they will be mismatched.
kind regards
Marek
#5
Posted: Mon Jan 04, 2016 10:27 am
by Robert Hiland
- you can buy a set of lead caps to increase you post diameters
- you can buy a set of new terminal connection leads
- you can buy a set of cables
All inexpensive answers to your problem.
#6
Posted: Mon Jan 04, 2016 7:39 pm
by andrewh
Thank you chaps. So I have looked into buying post shims but cannot find a UK supplier as yet. What I did notice is that my new "period" battery has a plastic red washer on the post. This appears to stop the lead from slipping down fully on the taper so may be the reason it's not tightening up . I have removed it and tried again. The earth lead is under the fan motor so quite tricky to get a real downward pressure when tightening . Ah well I hope it will work. .
#7
Posted: Mon Jan 04, 2016 7:56 pm
by chrisfell
Shim stock is available in your domestic recycling bin. Find a beer or cola can. I've been using these as shim stock and aluminium sheet stock for years. I always have several cans with the ends cut off all rolled together on my bench (ordinary scissors will do - the ally sheet is very thin)
#8
Posted: Mon Jan 04, 2016 8:04 pm
by andrewh
Yes but is it ok in that application? E.g will it conduct ok without corrosion or decay? I am not a metallurgist !!
#9
Posted: Tue Jan 05, 2016 4:47 am
by PeterCrespin
andrewh wrote:Yes but is it ok in that application? E.g will it conduct ok without corrosion or decay? I am not a metallurgist !!
No it won't. It is covered with lacquer inside (would not last long with carbonated drinks inside if it wasn't). I'm not sure if the lacquer responds to paint stripper but it's very fiddly abrading the whole surface area I expect. Ditto the external finish. Better to use an uncoated alloy pie dish.
Having said that, it's a 50-100 grand car, why don't you just buy the right size clamp or complete cable(s)? They cost less than a tank of fuel probably. There are heavy currents going though those connectors so don't faff about with shims IMO.
#10
Posted: Tue Jan 05, 2016 6:17 am
by abowie
Hope's smoke-pall rises
Wires' lives burn fleeting away
I've stuffed up again
#11
Posted: Tue Jan 05, 2016 8:24 am
by andrewh
PeterCrespin wrote:andrewh wrote:Yes but is it ok in that application? E.g will it conduct ok without corrosion or decay? I am not a metallurgist !!
No it won't. It is covered with lacquer inside (would not last long with carbonated drinks inside if it wasn't). I'm not sure if the lacquer responds to paint stripper but it's very fiddly abrading the whole surface area I expect. Ditto the external finish. Better to use an uncoated alloy pie dish.
Having said that, it's a 50-100 grand car, why don't you just buy the right size clamp or complete cable(s)? They cost less than a tank of fuel probably. There are heavy currents going though those connectors so don't faff about with shims IMO.
I rather hope its worth a tad more than ?50 to ?100 grand!
The cable is from SNG and is not perfectly uniform internally, but is correct, braided lead and is already fitted. The battery is supplied by Fosseway and would appear to be ok, but either way the lead does not fit snuggly on the battery. I removed the plastic red earth tag which has allowed the lead to fit down a bit more and appears to have tightened up. We will see.
#12
Posted: Tue Jan 05, 2016 12:39 pm
by David Oslo
Andrew
The earth lead terminal that you're trying to get to clamp onto the red battery post, new from SNG, is that the brass cup style, with the screw through the top ? (or is it the modern split-C with squeeze bolt)
If the former, then I wonder if the height (or length) of the terminal on the Fossway battery is hindering the brass cup from getting low enough to engage cone - cone, in essence it would be bottoming out without the brass cup getting low enough, in which case the fix would be to shave a few millimeters off the top of the Fosseway terminal
Maybe a picture would help out?
#13
Posted: Tue Jan 05, 2016 1:31 pm
by chrisfell
PeterCrespin wrote:andrewh wrote:Yes but is it ok in that application? E.g will it conduct ok without corrosion or decay? I am not a metallurgist !!
............ Better to use an uncoated alloy pie dish.
I keep these as well. Not flan dishes as they have perforations......
Oh dear... I've wandered into OCD territory again.
#14
Posted: Tue Jan 05, 2016 1:35 pm
by Heuer
David
The Lucas 'helmet' connectors are lead alloy and are available from SNGB.
More info here:
viewtopic.php?p=42758
#15
Posted: Tue Jan 05, 2016 5:10 pm
by David Oslo
Thanks for the picture, I have them on my car so am quite familiar with them :D On my last post I was suggesting that Andrew post a picture of his particular dilemma.
Mine are brass (or bronze) as can be seen from the dull brown finish. Underneath I've polished a bit to show the yellow metal, the green corrosion is a typical sign of brass / bronze. The lettering is a bit flattened from being hit with a hammer over the years.
On other British car forums I see references to three different materials in use, lead alloy, natural brass/bronze, lead coated brass/bronze.

#16
Posted: Tue Jan 05, 2016 5:47 pm
by andrewh
Heuer wrote:David
The Lucas 'helmet' connectors are lead alloy and are available from SNGB.
More info here:
viewtopic.php?p=42758
this is what I have on my car exactly, and from SNGB. Quite simply it is a loose fit on the battery, but since I have removed the red plastic washer it has appeared to fit down a bit lower so may now hold. Its not a very good fit though to be honest. I may be forced to try another lead if this persists. thanks all though.
#17
Posted: Tue Jan 05, 2016 11:45 pm
by PeterCrespin
andrewh wrote:...this is what I have on my car exactly, and from SNGB. Quite simply it is a loose fit on the battery, but since I have removed the red plastic washer it has appeared to fit down a bit lower so may now hold. Its not a very good fit though to be honest. I may be forced to try another lead if this persists. thanks all though.
Cal it women's intuition, but I suspect the connector is OK but the lead post is wrong. We shall see. To improve the fit on your bottoming-out connector you would shave the base of the cap, NOT a few millimetres off the top of the Fosseway post, which would make the problem worse.