Making An Autolite Group 24 Battery

When I first got my “project” Mustang that needed a little attention should we say, one of the first jobs I done was to wire her up. the reason being was I needed to know if the engine would fire up. To do that I needed a battery. At the time my wife decided that I should get what I wanted and do it properly. With that we decided to go mad and splash out on the replica Autolite Group 24 Battery.

Before I new Mustang Maniac it was a little difficult to try and track down parts I wanted, so I used a rather rubbish company in Essex. I won’t name them, but lets just say it took them almost four months to get the battery for me. Needless to say I used them once and never used them again.

I had done my research about the battery and found out it was based around a gel battery or AGM (Absorbed Glass Mat). These batteries are naturally more expensive and don’t hold anywhere near the amount of acid as a normal wet lead cell battery. In fact if it splits there should be no acid escaping. The battery needed a specific trickle charger as they don’t like to run low on volts. I reviewed the Ctek MXS 5 charger here.

After five years of owning the battery and using it for just two years it died. There was no warning it was about to go to the great scrap yard in the sky. The only warning was that the trickle charger showed an error instead of the normal charged status. I tried to start the car and there was just enough power to put the interior lights on. Turning the key gave me nothing, just a faint click of the solenoid. It was dead, I tried the charger on deep cycle to try and recover it thinking it need a little TLC. Checking a day later it was still the same, no charge what so ever.

Why did the battery die so quickly?

I researched this again, and it turns out that the AGM or Gel batteries have a limited life cycle for recharging. So if it’s down by 10% that means you have a remaining 90% for a single cycle. Bearing that in mind these batteries are estimated to have approx two hundred cycles life span. That is not a lot of use. Over five years it has been on constant trickle charge and only “used” when the car is taken out. So I’m not convinced this is the correct answer, I think it was a lot less than that in fact!

Anyway, I was gutted. I didn’t have my nice old school battery which looked the part. Now I would have to have an out-of-place new style battery. There are plenty to choose from of course with various power options. I was not going to pay that sort of big money again for another replica car battery when it didn’t last that long, maybe when I am little more flush with money? I had a word with Adam at Mustang Maniac and he said I could go for a replica cover for the top of the new battery to make it look more retro. The problem is that the top cover is the correct size and needed a battery to fit it. To small and the top would overhang the battery looking stupid, to big a battery it wouldn’t fit anyway. The other issue is that the positive and negative poles needed to be the right way around.

The part you need is the Autolite replica top, with caps and warning tag. Click here for the link or copy this to your browser:

Now I needed to search the net for a battery to fit the dimensions. I found out that sizes were limited for the power I would need, and then the terminals would be the wrong way round. After what seemed liked days of looking I eventually found a battery with the correct sizes, a flat style top, the terminals correct and enough amps for the Mustang to start.

That battery is made by Toyota with a part number of “28800 – YZZJG”.

The battery was rated at a powerful 75Ah which would be plenty to spin the V8 over. So I ordered it and a few days later I went to pick it. But first I needed to check that the top fitted, once it did I bought it. I parted with my £100 and brought it home.

So what did the top look like fitted close up? Well it fitted perfectly on the flat top, but the battery case side were a little inset from the top of the actual battery top.

There was another problem that was more annoying than an issue. On the original ’64 – ’66 battery tray the battery was held down by a bracket on a lip on the sides of the battery to stop it moving in the tray. This battery doesn’t have that, but I did have a plan. There is a work around for most things, you could make it work by replacing the battery tray to allow having an over the top clamp. That would fix the issue, but it wouldn’t be correct for the year. There needed to be another way to hold the battery safely in place. Below pic shows the hold down lip on the replica battery at the sides.

The new battery has its hold downs on the front and back which were not going to be used. I thought about using 3D printing to make a bracket, but the space to fit the clamp I thought of using would have been to flimsy and I suspect that it would have broken when being tightened down. The underside of the battery had recessed areas, that gave me an idea.

Underside of battery

I could create a lip up the side if I used a “P” shape idea, the down stem of the letter becoming the anchor point underneath of the battery. I would need to attach it somehow, so screws were out of the question. Glues wouldn’t have much surface area to hold the platform on the underside. While having a look through my tool boxes for inspiration and ideas I put my hand on it; epoxy putty!

The plan was to fill the cavities with the putty and create the anchor point base for the bracket. I would then fill the newly created “L” shape to mould a ledge that would bond to the battery side and the plastic anchor plates.

I roughed up the surfaces that needed fixing to allow a good surface to for the bonding. I would do this in two stages, mix up enough for the cavity areas to bond the plates in place, then roll a cylindrical shape to squash into the newly created corner creating the ledge I would need, then allow it all to set hard. The putty is mixed 50/50 black and white compounds until it becomes a grey colour and warm to the touch, then it’s ready to apply. I used the replica battery for how a guide on how much I needed to create the ledge for the clamp.

The POR15 epoxy putty sets rock hard which can be drilled, sanded and painted. Once the putty was set for a full twenty-four hours, I could see that it had bonded very well to the hard plastics of the ledge as well as to the side of the battery case. On the underside I also used a hot glue gun with super strength glue sticks to go over the edges and any spaces to add another form of adhesion. The battery clamp itself is held down by a single bolt through the battery tray and it just applies downward pressure to hold the battery down. The clamp has a couple of ridges on the underside that help locate the clamp in place and stop the battery movement. These profiles would need to measured to the middle of the battery and marked up accordingly.

Using my Dremel with a sanding wheel I leveled of the top of the ledge flat. Then I started rubbing the clamp onto the dried out white putty which left a clear mark where I needed to match the underside of the clamp profile.

Once I was happy with the clamp fit, the underside angled profile for the tray was copied from the original battery or could be seen from the battery tray itself. This would also ensure that the battery would fit back into the tray correctly and not sit proud on the clamp side.

Masking up ready for spraying was simple enough, although this step is not essential for what I had in mind. A couple of coats later from the satin black spray can made the ledge look almost stock which could have be placed into the tray as it is.

I wanted to do more to make the battery look more authentic. As I may want to reuse the top cover again I needed a solid, but not permanent solution, that came in the form of a black silicone mastic sealer.

I applied a generous bead around the gap from the visible side and front, with slight hold blobs on the back and other side of the battery. The reason the silicone wasn’t all the way round was to allow the battery to “breath” or allow any gasses to vent out. Sealing all around would have prevented this function if needed it.

I used a thin piece of straight plastic to create the initial seal between the top and the side of the battery to scrape the excess away in a flat surface to give the appearance of flat plastic. This would make it look like a complete battery not just a top. I allowed the mastic to go off a little more before I smoothed it again properly.

The next part was the case of the battery itself. The original design had a woven weave look which I wanted to try and replicate.

I had some vinyl left over from my toolbox draw project and I decided to use that. I cut lengths that I needed to go around the battery and cleaned and dust or grease from the now clean sides.

OK, so it’s diagonal and a carbon look, but in the engine bay tucked in a corner it would be difficult to see anyway. The wrap started at the top down to the corners taking care to make sure they looked neat. The new ledge was covered over with the wrap to give a nice continuity. So the battery now had a carbon fibre look which was just starting to be used properly in the early to mid sixties.

Next was the battery filler caps that I wanted to modify a little in order to be closer to the original. The caps didn’t have the tiny breather holes, but had the mark in place. These caps are the same size just the one on the right was has a screw thread which means it was closer to the camera to make it look bigger showing the hole.

A small 1.5mm drill was a perfect size to drill the hole out on the cap on the left.

Fitting the caps back to the top finished the look of the battery.

The original battery also had the word “Sta-ful” painted the same colour as the “Autolite” wording which was missing from the top plate. This was painted on once the battery was in the tray and secured.

Fitting the battery back into the tray was dead simple and the clamp fitted perfectly on the matched profiled for the clamp and the tray itself. The look of the carbon fiber wasn’t to far away from the look I wanted.

The final part was that cables were to be connected and the tag applied to the battery, (which should be on the positive terminal post by the way, not the neg side as I have it here). I also have some post felts which stops the cable fittings scratching the battery top, they also cover the tiny gap around the posts.

The finished battery!

It took about three hours work to clamp and silicon in place and I am happy with the results. My original review of the Autolite Group 24 Battery is here.

So what was inside the Replica battery in the first place? Click here to find out or cut and past the following into the browser: