Copper ring terminal on car battery the cause of corrosion?

Four wheel driving. Vehicle modifications. Off road driving and recovery techniques. Towing and miscellaneous vehicle topics.

Copper ring terminal on car battery the cause of corrosion?

Post by Lorgar » 30 Jun 2019, 12:40 pm

Hi folks,

Here's the situation: I have an auxiliary battery in my 4wd that's been in for about 2 years (installed + bought the battery at the same time, all new). All good, no problems to date, except a bit of corrosion building up at a fast rate on the positive terminal on the battery.

On the trip out this weekend, the fridge was running fine while the engine was running, but as soon as it was off would only last about 2 minutes before turning off and throwing the error code for voltage drop.

So poked around under the hood, found the positive battery terminal for the auxiliary just caked with corrosion; layered in between the ring connectors, battery, and clamp, and a full mm think and stuck on hard to the whole outside.

So I scrapped off what I could in the field (a poor job), and reconnected, fridge lasted 20 minutes after that. (Then died, but the truck had only been running 5 minutes to test after cleaning the terminal a bit so I'm assuming it was not charged properly as a result of the poor connection. Also the water was low, which I topped up when I got home. But haven't had driving time yet to charge and test again.)

In all this though, I noticed that the ring terminals the installers have used for the positive terminal on the auxiliary battery are copper. At the rate the corrosion builds I would have to be scrubbing it once a fortnight to keep clean which obviously isn't right.

The negative on the auxiliary is nickel/steel (I think? whatever they normal stuff is), and both on the starter battery are the same. These are all perfectly clean, and the starter battery terminals have hardly been cleaned in 10 years, so can rule out an environmental cause.

Is the copper terminal causing galvanic corrosion?

Should I be switching the connector rings to something not copper?

Seems like the obvious cause as it's the only difference, but I'm no electrician.

Cheers :drinks:
Last edited by Aster on 30 Jun 2019, 2:56 pm, edited 3 times in total.
Reason: post moved.
User avatar
Lorgar
Lieutenant
Lieutenant
 
Posts: 2382
Victoria

Re: Copper ring terminal on car battery the cause of corrosi

Post by TassieTiger » 30 Jun 2019, 4:52 pm

I’d hot water the corrosion off and then grease the crap out of + terminal and connector.
Your negative connector is an earth lead but your positive is current out - reason for diff materials in clamps.
Just cover post in grease when clean and it should work better.
Tikka .260 (custom)
Steyr Pro Varmint .223
CZ455 .22 & Norinco .22
ATA 686 U/O 12g & Baikal S/S 12g.
Adler a110 28’
Sauer 30-06
Howa 300 win mag.
TassieTiger
Second Lieutenant
Second Lieutenant
 
Posts: 2015
Tasmania

Re: Copper ring terminal on car battery the cause of corrosi

Post by bigfellascott » 30 Jun 2019, 4:59 pm

User avatar
bigfellascott
General
General
 
Posts: 6207
-

Re: Copper ring terminal on car battery the cause of corrosi

Post by Noisydad » 30 Jun 2019, 6:20 pm

Hot water with a table spoon of bicarb in it. Then make a good fitting washer to go on the terminal under the cable from thin foam or leather and soak it with grease. You’ll never have to deal with corrosion again.
There's still a few of Wile. E Coyote's ideas that I haven't tried yet.
User avatar
Noisydad
Sergeant Major
Sergeant Major
 
Posts: 1551
Victoria

Re: Copper ring terminal on car battery the cause of corrosi

Post by GQshayne » 30 Jun 2019, 8:45 pm

I have tried a number of things to prevent terminal corrosion over the years, including proper terminal protector products such as CRC and Wurth. I have also tried WD40, grease, Vaseline etc. I forget what else, but basically anything I could think of.

And then one day I cleaned up my corroded terminals (again) and for what reason I don't know I squirted them with straight lanolin. You can buy a few things with lanolin in them such as Inox etc, but I had straight lanolin. That was about 10 years ago maybe. I have never had a corroded terminal ever again. I am told that lanolin is electrically inert, and that is why it works.
GQshayne
Corporal
Corporal
 
Posts: 303
Queensland

Re: Copper ring terminal on car battery the cause of corrosi

Post by on_one_wheel » 30 Jun 2019, 9:38 pm

Hot water and bicarb clean as Noisy said

Followed by a rinse, level check if it has serviceable caps.

Most importantly check to see if your charging at the correct rate, check it at idle and at revs.

Overcharging will cause excessive hydrogen gass bubbling and acid mist leaking out. That will cause corrosion.

As for terminal protection, I like to use the spray cans designed specifically for battery terminal protection, it's that waxy yellow stuff.
After watching grease catch on fire on a battery post I dont like to use anything that catches on fire easily.
Gun control requires concentration and a steady hand.


on_one_wheel LIVES LEFT: 3..BONUS POINTS: 8

Did my post offend you? If you answered yes, send me a PM and I'll direct you to the nearest safe space.
User avatar
on_one_wheel
Lieutenant
Lieutenant
 
Posts: 2468
South Australia

Re: Copper ring terminal on car battery the cause of corrosi

Post by Lorgar » 01 Jul 2019, 9:55 am

TassieTiger wrote:Your negative connector is an earth lead but your positive is current out - reason for diff materials in clamps.


Hi Tassie. Ok, so there's logic in using the copper connector. How much is that required though?

As mentioned, the starter battery is on a standard nickel(whatever) connector and has been perfect for 10 years.

I'm thinking 'improved function vs hassle'. What is the copper connector doing for me in exchange for the maintenance required, that a nickel connector wouldn't?



Thanks for the link BFS. And for the product tips from all.
User avatar
Lorgar
Lieutenant
Lieutenant
 
Posts: 2382
Victoria

Re: Copper ring terminal on car battery the cause of corrosi

Post by Lorgar » 01 Jul 2019, 10:02 am

on_one_wheel wrote:Followed by a rinse, level check if it has serviceable caps.


Caps are good. Water was down, now topped up.

(Battery built in indicator did report "battery ok" before top up. Now reporting "charge battery" on the inbuilt indicator immediately after the top up, haven't had a chance to go for a drive yet to charge it.)

on_one_wheel wrote:Most importantly check to see if your charging at the correct rate, check it at idle and at revs.

Overcharging will cause excessive hydrogen gas bubbling and acid mist leaking out.


Can do that. What should I be looking for exactly?

12v while engine off.
14.4v while engine at idle.
14.4v while engine revving.

?

I assume if voltage is significantly above 14.4v while revving that's overcharge?
User avatar
Lorgar
Lieutenant
Lieutenant
 
Posts: 2382
Victoria

Re: Copper ring terminal on car battery the cause of corrosi

Post by on_one_wheel » 01 Jul 2019, 12:41 pm

Lorgar wrote:I assume if voltage is significantly above 14.4v while revving that's overcharge?


That would probably be acceptable. You probably wouldn't want much more than 14.4v
I get 12v engine off and 13.8v at idle and 13.8at revs.

My voltage regulator rectifier pood itself not long back and I had 12v off, 13.8 at idle and I stopped reving the engine when I saw 27v :o
My battery was boiling, there was acid everywhere, and the sides were buldging out like it was moments from going BANG!

Another cause of excessive breathing, acid splatter and corrosion can be over drawing from the battery,
Hard to start / lots of cranking the starter, too many spotlights and accessories....
Gun control requires concentration and a steady hand.


on_one_wheel LIVES LEFT: 3..BONUS POINTS: 8

Did my post offend you? If you answered yes, send me a PM and I'll direct you to the nearest safe space.
User avatar
on_one_wheel
Lieutenant
Lieutenant
 
Posts: 2468
South Australia

Re: Copper ring terminal on car battery the cause of corrosi

Post by Noisydad » 01 Jul 2019, 1:13 pm

OOW I’ve seen a battery explode. Makes for an interesting day!
There's still a few of Wile. E Coyote's ideas that I haven't tried yet.
User avatar
Noisydad
Sergeant Major
Sergeant Major
 
Posts: 1551
Victoria

Re: Copper ring terminal on car battery the cause of corrosi

Post by on_one_wheel » 01 Jul 2019, 2:33 pm

Noisydad wrote:OOW I’ve seen a battery explode. Makes for an interesting day!

:lol: sure dose.
Gun control requires concentration and a steady hand.


on_one_wheel LIVES LEFT: 3..BONUS POINTS: 8

Did my post offend you? If you answered yes, send me a PM and I'll direct you to the nearest safe space.
User avatar
on_one_wheel
Lieutenant
Lieutenant
 
Posts: 2468
South Australia

Re: Copper ring terminal on car battery the cause of corrosi

Post by TassieTiger » 01 Jul 2019, 4:29 pm

Lorgar wrote:Hi Tassie. Ok, so there's logic in using the copper connector. How much is that required though?

As mentioned, the starter battery is on a standard nickel(whatever) connector and has been perfect for 10 years.

I'm thinking 'improved function vs hassle'. What is the copper connector doing for me in exchange for the maintenance required, that a nickel connector wouldn't?


You Re using the battery for more than design now. You obviously have a multi - change terminals and measure the drop of V at starter with copper clip on vs nickel.
Tikka .260 (custom)
Steyr Pro Varmint .223
CZ455 .22 & Norinco .22
ATA 686 U/O 12g & Baikal S/S 12g.
Adler a110 28’
Sauer 30-06
Howa 300 win mag.
TassieTiger
Second Lieutenant
Second Lieutenant
 
Posts: 2015
Tasmania

Re: Copper ring terminal on car battery the cause of corrosi

Post by Lorgar » 01 Jul 2019, 5:04 pm

on_one_wheel wrote:That would probably be acceptable. You probably wouldn't want much more than 14.4v
I get 12v engine off and 13.8v at idle and 13.8at revs.


My voltage regulator rectifier pood itself not long back and I had 12v off, 13.8 at idle and I stopped reving the engine when I saw 27v :o
My battery was boiling, there was acid everywhere, and the sides were buldging out like it was moments from going BANG!

Righto. Will check and post back.

I would say at a glance there is no structural trouble with the battery. No visible swelling etc.

I don't think there is any/much leakage. Mostly confined to on, or directly around the terminal.

on_one_wheel wrote:Another cause of excessive breathing, acid splatter and corrosion can be over drawing from the battery,
Hard to start / lots of cranking the starter, too many spotlights and accessories....


I would say load is not an issue. The auxiliary battery has only ever had to run a single 40l Waeco fridge, and charging a 12v torch half a dozen times. It's never been connected to anything else, never been used to jump a flat starter, etc. etc.

We'll see what the voltmeter says anyway.
User avatar
Lorgar
Lieutenant
Lieutenant
 
Posts: 2382
Victoria

Re: Copper ring terminal on car battery the cause of corrosi

Post by GQshayne » 01 Jul 2019, 7:32 pm

Perhaps you are looking into this too much. It does happen. A lot.

As for prevention, I have used specialist terminal protector stuff, from more than one company. Had the terminals spotless, sprayed it on, and watched it start corroding again. Done this on a number of machines too, so I had a lot to look at under my control.

I had an old dual battery, terminals and clamps corroded badly too. But I was not ready to replace it all even though it was buggered. Lanolin stopped it instantly.
GQshayne
Corporal
Corporal
 
Posts: 303
Queensland

Re: Copper ring terminal on car battery the cause of corrosi

Post by av1 » 01 Jul 2019, 8:06 pm

Use hot water to clean terminals, then remove terminals from battery and ensure battery posts and terminals are clean. If cleaning is required, use a fine file or sandpaper (not emery paper).

Refit terminals and apply a dielectric grease or Vaseline, never apply any grease between the battery post and terminal.

Corrosion around battery posts is caused by incorrect tightening of battery terminals, resulting in fractures around battery posts thus allowing acid fumes to leak and creating corrosion.

Hope this helps.
av1
Recruit
Recruit
 
Posts: 12
Victoria

Re: Copper ring terminal on car battery the cause of corrosi

Post by GQshayne » 01 Jul 2019, 8:46 pm

In my experience, Vaseline, or another petroleum jelly, has not worked.
GQshayne
Corporal
Corporal
 
Posts: 303
Queensland


Back to top
 
Return to Four wheel driving and off road travel