Sunday, November 9, 2008

Making It All Fit

I want Lithium Phosphates, but for planning purposes I'm going to size the battery compartment for Trojan J-150s. If I can fit 120V worth of Lead in the car, I can definitely fit 120V of Lithium. I found an old box and cut it to the shape of 4 J-150 batteries. It should be a few inches longer, but that dimension isn't critical for sizing purposes. The cat wasn't happy with me dismantling his playhouse.

It's a very close fit underneath the car, and there is no way one of those Trojan batteries will fit in the car's original 12V spot. Looks like I'll have 4 up front, 6 in back.

I picked up a 24"x18"x1/4" sheet of Plexiglass from Home Depot - it will be my base for all the smaller electrical components: relay, contactor, fuse, shunt, controller, dc-dc converter, etc...

Looks like it will fit nicely over the motor. I'll trim down the top piece to 12" x 24", and then cut a mounting piece that will go along the side.

Rough fit, looks like it may work. By the way, if you ever get the opportunity to cut a sheet of Plexiglass with a Jig Saw, pass. Go too slow, the piece you just cut melts back together. Too fast, you crack it. Not fun.

I finished up the cutting and went to fitting brackets to connect the two pieces.

Plexiglass all cut out and bolted together.

Let's see how it fits in the car.

Looks great! It actually doesn't fit quite right on one of the sides. I assumed the supports for the engine were symmetrical (and visually they look like it), but they're actually off by about 3/4". Oh well, it still looks okay. There are a couple existing mounting holes I'm going to bolt through to the front plexiglass piece. In place, the plate should sit about 1" above the motor. I hope the heat from the motor doesn't start warping and/or melting my plexiglass!

If I were really fancy, I'm sure I could design a complex metal frame that would hold a couple more batteries and all the electrical components tight around the motor. That might be good for space reasons, but I foresee a design, fabrication, and maintainability nightmare. An extra battery in the trunk isn't that big of a deal.

In other news I got my Christmas present!

Two of my tires are good, but the other two are cracked to the point I'm surprised they still hold air. My wife talked to someone on the diyelectriccar discussion board and found some great replacement tires for me. There's nowhere she could hide them for 2 months without me noticing, so I got them early! You gotta love a wife that buys you tires for Christmas!

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