I have been asking around for dimension and what not for dual battery trays. Finally decided to just give it a shot on my own... more or less.
I was rather surprised to find out how easy this way.
3/6" x 1" angle iron (approximately 5 feet: pretty much on the money
3/16" x 1" flat stock (spproximately 1.5 feet: conservative
3"16 x 2" flat stock (approximately 1.5 feet: conservative
4"x3"x3/16" flat stock which will be used for the tray mounting tab
Qty: 3- 5/16 all thread approximately 9" each
Qty: 3- 5/16 wing nuts
Qty: 3- 5/16 lock washers
Qty: 2- bolts 7/16" x 1.25" (16 thread count)
Qty: 2 nuts 7/16" (16 thread count
Qty: 2- 7/16" fender washers
Qty: 2- 7/16" lock washer
Welder (120v or 220v will work fort his)
Angle grinder with cutting wheel and flapper wheel
Drill press or drill with 7/16" bit
6 pack Sierra Nevada Pale Ale
Remove the OEM battery tray, OEM jack (if you still have it), fender to battery stray struts, and charcoal canister (if you still have this as well)
Cut angle iron to the following lengths
2 pieces at 14"
4 pieces at 10.5"
Cut 3/16" x 1" flat stock to the following lengths
2 pieces at 6.5"
Place the two pieces of 14" angle iron on your work bench and place 2 of the 10.5" pieces on the outer parameter (overlapping the 14" pieces on top) and tack weld these in place to form a 14"x10.5" rectangle.
Grab the remaining two pieces of 10.5 inch stock and clamp them side by side as square as possible so they are in a "T" shape with one another. Weld these pieces on both sides with several beads on each side. Each bead should be about 1" long.
Find the center of the rectangle and drop the newly welded "T" channel in and tack this in place as well. This will leave you two different battery compartments on the dual battery tray. Please excuse this picture as I forgot to take shots before I mounted the center support tab and placed it in the jeep. Furthermore, disregard the pieces of stock in the inside of the battery tray at the moment as I will cover this here shortly..
Take the old battery tray and make an EXACT duplicate of the mounting tab with the 4"x3"x3/16". Drill 7/16" holes when making the duplicate. Again, I did not take a picture when I was in the process of making the tab, but you can see the tab close up installed in this pic. Disregard the weld at the moment.
At this point, you are going to take the mount pictured above and mount ONLY this to the firewall in the same location the OEM tray was mounted to. Since people have different engine bay compartments (gadgets and gizmos), I cannot confidently give an exact location to where you are going to want to tack weld the tray to this mount. However, I positioned the tray above the fender struts (support arms) and tacked the battery tray to the mount with in the engine compartment. If you are going to do this, make sure you put a towell or something over the fuel lines!
Then, I was able to determine the approximate location of there the fender struts/support arms are going to line up with the tray and marked the area. At this point, I took the tray back out and then grabbed the 2 pieces of 3/16"x1"6.5" and tacked them to the bottom portion of the tray in the approximate location to where the fender struts / support arms were to line up. When the tray is positioned where it should be, you will want to mark the locations on these 2 pieces of metal where they line up with the support arms. Mark the location with a dot on the metal and this will be the reference point where you will have to drill holes. As you can see in the picture, I accidently welded one of the pieces in the wrong place, but I certainly didnt hurt anything, so I just cut and welded another piece where it should have been in the first place...
Once this is done, you need to reinstall the tray the two bolts and rest the tray on top of the fende strust / support arms. At this point, I took the
3/16"x2" stock and copied the passenger side support bracket to get the correct angle so it rests flush with both the battery tray and the firewall. I then hand placed the piece on to the battery tray, and while keeping the firewall portion "square" to the firewall, I tacked in this support bracket.
The next part of the install you have to get creative. To utilize the oringial nutsert on the firewall, you have to cut to shape this piece for the passenger side support bracket. Do several trial fits if needed
Once this is done, you can swing the piece above to the passenger side support arm and tack in place.
At this point, take the tray back out and permanently weld everything together.
Rough dimensions / sketch of the tray installed. Should be able to hold 2 decent size batteries.
With the tray once again removed, drill two holes in the metal where the suport arms were marked. Insert the nuts through the top of the batter tray and weld them in place
Use the angle grider with a flapper wheel and grind down the bolt heads until they are flush with the angle iron
Now its time to install the angle iron. Mark the center of the battery tray all the way across and tack in the all thread. Ensure the all thread is perfectly perpendicular as possible. In the center of the battery tray, you will have to take the angle grinder with the cutting wheel and cut a notch for the all thread to be seated in. Once everything is tacked up and looking good, go ahead and weld all the angle iron in permanently
Once the angle iron is in place, you will need to make a battery strap. I did this by using 15 inches of 3/16"x1" flat stock. I marked the locations of the angle iron on the flat stock and drilled 3/8" holes through the stock to make a strap that fits the entire battery tray.
PIC TO COME SHORTLY
Take the flapper wheel and grind off all the "dingle berries" to prep for paint. Hang the battery tray and paint away.
Reinstall tray in to jeep, add batteries, and voila, you have a dual battery tray.
THIS WILL BE EDITED SOON TO MAKE IT A LITTLE MORE CLEARER