Battery Wiring

Battery Boxes
As you can see all of the battery enclosures are done and insulated except for the long narrow one. You may also be able to see that the larger box has an additional liner inside, which is actually just another box like the outside one. I made this for the additional support since there will be eight batteries for five hundred pounds of distributed weight. I haven't decided if the lids will be transparent Plexiglass for ease of inspection or solid, insulated panels like the rest of the box.

Before & After Cosmetic Surgery

Finally got the opportunity to practice my creative corrective surgery techniques. The patient in the left picture was suffering from an extruded metallic hump, not unlike the shape found for storing a spare tire. You'll notice the clean lines and open smile in the post surgery snapshot on the right.
I'm hiring a local welder to take care of the front and rear battery box supports and frames. After playing around with my friends MIG welder I decided that I didn't feel comfortable enough with my welding abilities (nor want to spend a long time learning) to trust them in what is a major piece of the project. I called around and found a fellow who welds and does car body work as well. As he looked it over and talked about the options I learned that this wasn't his first EV! He's done some body work and welding on an Electric Truck conversion for the Town of Hanover. I feel much better now that I have a solid plan for this section.

While he works on the welding I'm going to be starting the layout of the control electronics. Needing to be mounted and accessible are the controller, half a dozen relays, a fuse block, wire terminal strip(s), shunts, and the accelerator potbox. We're also getting close to having to worry about running cables among the battery boxes and the motor.

Battery layout & interwiring


The diagram above shows a rough outline of how the batteries will be laid out in the car. Eight batteries go in the rear trunk box, two of them above the motor, and the final two lengthwise where the radiator used to live.

For safety concerns I want to minimize connections where high voltages are right next to each other. All of the boxes have the main positive and negative leads come in at opposite corners. I'm not exactly sure about the lug layout on the batteries I'm getting so this may change slightly to accommodate.

The fuse in the rear battery box is a safety precaution in case something should happen to the cables or the front compartment. There are other fuses in the controller area, but this is the only one for our biggest battery section. All of the cables are heavy duty welding cable and the connecting lugs are crimped on using an aircraft hex crimper (which Bob Batson will rent out). Finally, heat shrink tubing is used to cover the exposed wire and lug junction, the lug is secured to a battery and a battery terminal cover is slipped in place.

The only outstanding issue with the batteries is the heater for warming the battery boxes during recharges in the winter. I've received a couple suggestions via email and I'll probably leave this in the to-do box for now, since I don't expect to need it until next winter. If you have suggestions (for this or other components) please drop me an email note by clicking the leaf at the bottom of the page.


I was going to place an order with EV America for the batteries and a bunch of other stuff but decided (at the advice of Bob) to hold off on the batteries until the very end. No reason to add a dozen batteries to the clutter in my garage while I piece everything else together. Bob suggests that the batteries and charger are the last things to buy, then once you get them hooked up and checked out you'll be ready to USE them.

In the meantime I can still order some of the other parts and start putting the electronics together.

My near term shopping list:

    2/0 cable (black & red) for batteries and motor.
    Battery lugs plus rent a heavy duty crimper and cutter
    Ignition triggered relay (on/off)
    Fuse block
    Wiring terminal strip
    Wire (smaller guages)
    Impact cutoff switch
    Ammeter & Shunt for between Motor & Controller(-300 to +600 amps)
    Anderson heavy guage connectors (SBX-350's & SB-50's)
    Clear Vinyl Hose - protection for battery cable running under the car
    Heat Shrink tubing


© Copyright 1995-2002 Jerry Halstead