Mustang Battery Tray Trouble

Early Mustang Battery Tray Issues

Originally Mustangs used BCI group size 22F batteries, or if the heavy-duty battery was elected, a size 24F battery.  In either case, Ford used flanges on the short side of the battery to hold it down to the Mustang battery tray.  Although they do exist, Group 22F batteries are practically impossible to find without some serious digging and/or special order-ing.  They’re also small and just adequate when it comes to supplying power and reserve capacity.  Group 24F batteries, however, are one of the most popular sizes on the market today, likely owing to their use in some of the best-selling cars of the last few decades.   Batteries in the 24F size are available off-the-shelf at practically any local auto parts store, and because they fly off the shelves, they’re usually pretty fresh and you have your pick of brands.

But…unlike the 22F batteries I’ve seen, most of the 24F batteries no longer have the flange molded on the short side of the battery, so they won’t work with the factory battery hold-down setup.  That leaves an interesting quandary: do I try to find a battery that fits the stock setup or do I change the car to use the 1967+ style setup?

Starting in 1967 Ford went to a more conventional, and certainly more secure, battery hold-down setup.  That setup uses J-bolts, nuts, and a top hold-down clamp to hold the battery to the tray.  And in fact, so many folks have faced this problem that there are multiple options to convert your early Mustang to use the later-style hold-down setup.  Given that 22F batteries need to be special ordered and that 24F batteries with the proper flange are getting harder and harder to find, as well as the fact that the later-style mount is more secure, I decided to change my tray to use the later setup.  Had I thought about it sooner, I could’ve bought a battery tray that was already modified to use the later-style clamps, but instead I had to buy an add-on piece that runs under the battery tray to add the J-bolt attachment points.

In order to install the hold down modification, I had to drill a hole in the battery apron for the screw, but other than that, no permanent changes to the car or the newly installed battery tray were required.  And because it’s under the battery tray, if I ever want to go back to a stock-style setup for show, I can and no one will ever know.  There’s not a lot of clearance on the front side of the battery tray with the battery installed, so mounting the front J-bolt takes some planning and fiddling if you don’t assemble everything in the proper order (the trick is to put the front J-bolt on before you install the battery and to then maintain upward pressure on it while you install the clamp so that it doesn’t disconnect from its mount point).  Even then, it only takes a few minutes to install the battery, and it looks just fine to my eyes.

One word of caution: always use a hold-down.  The forums online are filled with guys who say, “I couldn’t find a battery with the flange, so I don’t use a hold down, the battery is heavy enough to stay put.”  The battery may be heavy enough not to move around much, but it still moves around.  Vibration and banging side-to-side can dramatically shorten the life of a battery.  Also, in case you haven’t thought about it, the battery terminals are very close to the underside of the hood when it’s closed.  Do you really want to risk shorting the two terminals together momentarily if the battery bounces up and down over a bump?  The next time you see an early Mustang, check out how close the positive terminal is to the fender…it’s really close (which is why Ford installed a rubber shield there at the factory).  If your battery moves a little, it could easily short the battery out on the fender as well.  The whole hold-down conversion setup costs less than $30…why take the chance?