Rear Batteries secure

Today I got a late start due to a late night in Cincinnati. But, thankfully I figured out how to secure the rear batteries w/o taking up much space in the rear boot area and w/o too much cost. While I still am thinking I want to have frames welded on either side of the motor under the control board, for now this will work fine. I was on my way to looking around at auto parts stores for battery bolts (the 12" inch kind) and plates, when someone suggested visiting a tractor supply store. On my way I saw a few mini golf carts which had Escalade and Hummer bodies. Strange, but when I saw a sign that read "Electric Cars and Carts" on the windshield of one mini vehicle and saw they were actively displaying them in this small town called Gas City, IN, I had to stop. I spoke w/ the salesperson for the carts (based in Marion, IN) and he showed me the T-875 battery placement and how they fastened them to the carts. I was all set to go Monday morning to get the parts they sold for my battery pack, but for some reason on my way home I turned around and headed to the tractor supply place.

I found just what I ultimately was looking for. Again I want to weld the batteries to the frame, but want a less permanent and more maleable system for now so I can get this thing driving and then refine the layout later (I don't think I'll be one who just has this car all setup then ignore it for 10k miles). The picture above shows what one can find that can be cut w/ a reciprocating saw and drilled into for extra holes (or for enlarging one). I found both galvanized steel (which is what I'm using for the rear) and aluminum (which I'll use in front) L-shaped 'channel iron'. I also bough some of the long treaded 'bolt' shaft material for making long bolts since I could not find any 12" bolts that would fasten down a bracket set on top of the batteries. I basically ended up using strapping to secure the batteries to the steel frame that is bolted to the frame of the vehicle. With some bailer belt rubber cut to 1/2" strips, I put the rubber under the strapping to keep it from eating into the plastic in the batteries. Now, the 5 battery pack is snug against the back seat and thus will be easy to refill when necessary. Now I just need to fabricate a box that will slide over these batteries and provide a good seal so that I can control the ventilation. Here's what I have so far (picture is a bit dark since I just finished it at 930pm tonight):