I finally have me, daylight, and a camera at the same time, so you can see how the battery box is progressing.
Unfortunately, the battery box will only hold 5 batteries, not the originally planned 7. That's ok, we'll figure something else out.
Here's the battery box, as we got it on Sunday.
And here's the reverse angle.
I stripped out the rear batteries, allong with all associated cables, the charger, main contactor, and anything else that was back there. This gives me room to work, and help visualize where to put the other batteries.
As you can see, the battery box is welded directly to the unibody of the car. It's tack-welded in there pretty well. We need to put in some filler around two of the edges, and then weld the entire circumference of the box.
Here's what it looks like with five batteries in it.
I have one-inch-thick foam insulation on the back side of the box. On either of the two short ends, there is only enough room for 5/8 or MAYBE 3/4 inch insulation.
Also, right now, the batteries are sitting directly on the bottom of the box. Adding any insulation there will raise the batteries. I think I want rigid foam on the bottom, just thick enough to carve with a router to add in electric battery heater lines.
The other thing I am wondering about is if I should keep the back seat or not. I will not be using the back seat for passengers, as the car will have its gross vehicle weight maxed out. It might be nice to keep the back seat for looks. Have it look like a "normal" vehicle, with the batteries totally hidden away. To do that, the bottom of the back seat would have to be carved out to allow for the top of the box. It will no longer be comfortable to sit on!
The other way I could go is to have the whole back of the car be a flat cargo area. This would be similar to the back of a Honda Insight, although a little lower. If I did that, I would cover over the top of the battery box and the spare tire well with light plywood and carpet. I would have LOTS of cargo space, and I think it would look very nice. It also would be better for showing off the EV components, by not having any of the backseat in the way.
Here is a mock-up of the "cargo-space" concept, using scrap wood. In a finished version, the plywood would extend all the way across the car on the front edge. It could also sit about an inch and a half lower, as it is sitting on top of the old battery brackets (bedframe) in the back of the car.
To re-install the back seat, I would need to hollow out the foam of the seat bottom. The back seat would basically become the "lid" for the battery box.
With all the batteries removed, you can now see what I have available for space in the spare tire well. While it is an odd shape, it's plenty big enough for the charger, main contactor, and a couple other small items.
My master plan to fit 12 batteries (2 72V strings OR 1 144V string) in the car. I still want to do 4 in the radiator position, I just have to figure out how to do it. It may mean plasma-cutting a bit off the headlight buckets, but come on! How cool would custom headlights be! I could aeromod them at the same time!
4 batts in front and 5 in the box means I still need to find space for 3 more. Up against the firewall is where one of them is likely to go. That does mean more fabrication, and maybe covering up my motor.
Anyhow, let me know which you like better - the back seat back in, or the "Insight" cargo area.
-Ben
Today
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) might save you a few lbs for the cargo area cover. Using thin polyacrylic (plexi) might keep you from ever actually having to open it up, save for modifications and pointing out specific details, and Lexan is even lighter than Plexi is, and doesn't scratch as easily.
