Tie Down for an Optima Battery

By Bob Morris

The first drawing is the top hold down strap and is the exact dimensions. The small bend goes under the loop on the gas tank wall the anchored the rubber strap. On the other end I drilled a hole to insert a threaded bolt on one end and a U shaped bend on the other end. The U shaped piece hooks on to the front loop that the rubber strap was anchored. The second drawing is the piece that goes on the floor and holds the negative lead from the battery. It loops around the end of the battery. I also used a 1 X 12 " piece of wood on the finder side of the battery to keep the positive pole from touching the finder well. I used 1 X 1/8" galvanized metal stock to make the parts. You can use aluminum to make the top part, but need a conductive metal for the bottom part.

Optima battery top hold down fixture. Made out of 1" X 1/8 galvanized bar stock. This is a side view. Click for larger drawing.

Optima battery hold down, floor fixture. Made of 1 X 1/8" galvanized stock. Top view. Click for larger drawing.

Another Tie Down for an Optima Battery

By Jim Hawley

Originally I went to the store to get straps and follow the plans that Bob Morris offered in this description. But I ended up doing it in a (for me) much simpler way. I have a C coupe. I don't know how the battery hold downs are different for any others.

I have the original battery box which has a metal loop on the vertical wall behind the battery (to attach the original rubber strap, methinks). So I took a 1.25 X 1/16 X 4 foot (all you need is about two feet) aluminum strip and basically bent it in a square shape to fit around the battery.I bent it completely with a vise and my hands, then fit in in the box, then put the battery in.

An Optima is 7" tall and just about 3.5" deep. So the straps first leg is 8" long (to give about 2" to fit up under the little loop), bent at a 90 deg. angle. Because the loop sticks out about .75 inch, the length of the strap that the battery sits on is about 4.25 (the depth of the Optima plus the space needed to clear the loop). Next bend again making a square "U" shape. Come up 7.25", and bend to make a square "O" shape. Finally, measure the same 4.25" and then bend in the opposite direction of all the others. You should have 1" of the first 8" section touching the last section you bent. Cut off the strap with that 1" on the end, and you should have square inside dimensions of 7.25" by 3.5."

Drill a .25 hole in the top of the two pieces (the 1" tab and the end of the 8" section) and use a nut and bolt to hold it together. I had a nut attached to a thin "U" shaped bracket that came with my K&N's (bought from a lister--don't know what they were for) and I used that on the 8" section, so I didn't have to get a wrench in there to tighten things up.
Once you have it bent and drilled (before installing the bolt), slide the 8" section from below the loop and bend/twist it a bit until that part slips into the metal loop (which about 6" up from the bootom of the floor) on the vertical wall. The bracket should be sitting on the battery floor now. Then open up the bracket, slide in your Optima and attach the bolt.
Now you'll notice the battery isn't rigidly mounted (because of the .75 free play of the inside the loop. So I cut a piece of my old sill rubber 17.5" long (7" +3.5" + 7") and wrapped that around the strap and the battery seems fairly snug. I guess you could use 7" (instead of 7.25) on the metal strap to get a tighter fit around the battery, and stick a piece of wood into the loop, forcing it against the strap and then she don't move, but the rubber works great for me.

Updated 7/18/01