Battery Terminal Shims - WHY?

For like the third time in my life I’ve had a car who’s battery terminal, though tightened as much as it can go, is too large to fit snugly on the battery post.

Now I know the fix, and some of the horrible suggestions to hack the fix. But my question is, “Why can’t car manufacturers figure this out? Why can’t they make a terminal connector that will actually perform it’s purpose?”

Any 10 year old could engineer a better solution.
I mean I can see that they’re probably trying to get as much surface area as they can to touch the terminal, but the fact that I’m buying Terminal Shims for the 3rd car is kind of pissing me off.

I have the same problem with an older Durango. I stick a 2d nail between the post and connector.

Because car batteries have different size posts, and the car designers have no way of predicting what wrong battery the goober behind the counter at Sears is going to sell you. :wink:


I just looked up battery shims to see the price. Much cheaper than a new cable and gives good contact. Somehow this doesn’t seem like a major problem.

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I hate to say it, but shadow is right. Someone sold you the wrong battery. There are different size terminals for different applications.

I’ve had that problem too, and always wondered the same thing. Why can’t the car designers come up with a connection that accommodates for variability in post size. In my case it seems to fit correctly at first, but loosens over time. So I don’t think it is a problem with the initial post dimension. Either the connectors is widening or the post is shrinking over time. I suspect the latter, the post is squeezed by the connector and it compresses to a smaller dimension, I think the post is made of lead which is a soft metal. I’ve never used the shims, so far I’ve always been able to file a little on the connector enough to make the attachment sound again.

Then why haven’t you? I think the shim solution works pretty well. In the cases they are needed they are easy to use, relatively inexpensive, and most of. All they work. So really what’s your beef. Or getting the cheapest battery from the idiot at the local parts chain just not working out for you. After all, the only thing the counter monkey said is that it will fit. Not necessarily be correct.


The “better solution” is obviously the GM bolt-on battery terminals. No clamping issues, just screw in the battery bolt, snug it down and DRAT it STRIPPED AGAIN, dag nabbit!

Never mind…

Never, ever had to use shims to get a good connection.


Back in the ‘good ole days’ battery shops would repair battery posts. They poured liquid lead into a mold resting over whatever was left of the old terminal post. But if the posts and clamps are occasionally cleaned with a wire brush and the clamps properly snugged down rather than over tightening problems are usually avoided. Of course the tin hose clamp style cable ends are especially prone to stretching and breaking.

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Too often one product is made in Mexico and the connecting part is made in China. I had this problem with the gas line snap connector for my outboard motor allowing air to be sucked in and stalling the motor. Finally I replaced both the female part in the motor and the male part on the gas line at the same time using the same manufacture of each part. No more problems. I also had a similar problem with my garage door opener. The two light bulbs were loose in the sockets. Sometimes they would illuminate and sometimes they wouldn’t. I solved that problem by one wrap of tin foil around the light bulb threads.

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HAHA pat showing your age, or maybe a local colloquialism, but wikopedia says
" Actual tin foil was superseded after World War II by cheaper and more durable[1] aluminium foil, which is referred to as “tinfoil” in many regions"
If you have some tin foil left it may be worth money on ebay for making hats! :joy:

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Yeah, I was born before WW2. I guess you are a young whipper snapper who had to look up tin foil on Wikipedia. I sold all my tin foil back when to help in the war effort :slight_smile:

In case anyone does not remember that was the era of steel pennies, gas rationing, and our fair city even donated a civil war cannon, later replaced by a replica to the war effort.
Yes I had to look it up, only born in 54, (I keep saying that hoping some whoever would say 1854, or 1954)
Guilty as charged :slight_smile:

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Almost all 1943 pennies were made out of steel, but they still made a few 1943 pennies of copper (or maybe bronze), and if you found one, you’d increase the size of your bank account significantly. I think they go for around $100,000 each.

And speaking of pennies and shims, do any of you folks ever use coins to fix stuff? I’ve used pennies quite a few times to repair electrical parts.

For some reason, I’m envisioning George putting a penny into the socket of a house fuse that blew…



Not for fuses, but I’ve used a penny to fix my electric orange juicer for example. There’s a switching action that turns it on when you press the orange down, and after a few years of juicing that contact point wears out. I used a penny to make it good again. hmmm … I hope I didn’t use a 1943 bronze one … lol …

Sold? That was profiteering. Most just gave/donated to the war effort. :thinking: I wonder if it is too late to report you. :stuck_out_tongue_winking_eye: ( sarcasm)

I have vague memories of touring the neighborhood with my wagon looking for scrap metal, which I then took to a place that gave me a few cents for it.

The clamp type battery cable ends are soft and eventually distort enough where the bolt goes through that they touch and will not tighten. installing shims or removing the bolt and filing off the excess material both work fine. So does replacing the cables. This is not a factory defect just normal wear and tear.

A bit of lead/tin solder works well as a shim.
For me on hand and essentially free.

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