How to easily fit a modern battery in a classic car

Photography by Carl Heideman • Lead by David S. Wallens

Sometimes our classic cars don’t keep up well with modern times. While a lot of specific replacement parts like body panels, interior bits and trim pieces continue to be available in quality reproduction form, other more common wear-item needs like tires and batteries are, ironically, getting harder to find in the sizes we need.

Batteries can especially be a problem, as the sizes required by our classics are often no longer produced. Thanks to new battery sizes, many classic cars lack a properly fitting tie-down strap. As a result, many of them are running around with batteries that aren’t strapped down at all. 

This is downright dangerous—every battery should be properly secured. An unsecured one can come loose and short out, risking fire or explosion.

Installing a new battery into a classic doesn’t have to be hard. We recently fitted a new battery to our 1967 Jaguar XKE. When we got the replacement battery, it was the same length and width as the old battery; however, the new one was about two inches shorter. As a result, the factory battery hold-down would no longer fit. 

Since our car is not a concours queen that needs to remain 100 percent original, we quickly fabricated a safe and secure strap to hold the battery in place. Call this a quick way to make sure we’d be enjoying the XKE for years to come. 

While our strap would only fit a similar XKE, the procedure we used would apply to many other cars. It’s something you can easily do at home in an afternoon with only common hand tools.

Step 1.

Our original hold-down would no longer fit our new battery, which is about two inches shorter than the original piece.

Step 2.

We realized that we could quickly fabricate a simple steel strap to secure the battery. We took a few measurements to get a ballpark length.

Step 3.

Next we cut some 1/8x1-inch hot-rolled steel strap. The piece needed to be 14 inches long. We’ve found this type of steel strap to be the perfect material for battery mounts. It’s sturdy enough to do the job, but easy to work with.

Step 4.

We had to bend the ends to meet the mounting locations, so we used a five-pound sledge hammer and a vise.

Step 5.

After test fitting the strap and looking for good mounting holes to use, we realized that we needed to reorient one end 90 degrees. Again, we were able to bend it in our vise.

Step 6.

We then drilled holes in each end of the strap.

Step 7.

We tried to avoid drilling holes in our XKE. In the front, we used an existing bolt and hole (arrow 1) to hold the strap. Note the lug for the original battery hold-down’s J-bolt (arrow 2).

Step 8.

We did have to drill a new hole at the other end of our XKE. We chose to drill into another bracket rather than the body of the car itself.

Step 9.

We test fitted the new strap and found we had to do some trimming on one end. We did so with a grinder. Then we gave the strap a coat of silver paint in preparation for installation. We made sure the battery was unable to move; if the terminals came in contact with the strap it could cause a major short circuit.

Step 10.

Once installed, the strap held the battery safely in place while keeping it very serviceable.

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View comments on the CMS forums
9/9/20 3:53 p.m.


What prevented you from just shortening the bolts or having new one made to adapt the lower profile battery in this case? 



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