ElectricSubaru


Jun 7 2014 Last update:

Power Cabling

Routing

The power cables follow the path where the exhaust pipe was located, except the power cables go over the top of the rear cross member. The cables meet the main battery box at the left rear of the car, where the muffler was.

Route

There are lots of threaded holes in the bottom of the car for adding mounting brackets.

Power cable Power cable Power cable Power cable

The left rear tow hook posed a danger to the cables in the event of a collision, so it was removed. Another tow hook remains on the other side.

Tow Hook Tow Hook

Wiring diagram.

Wiring Diagram

Cable

The power cable between the batteries and the controller is TRYSTAR 2/0 AWG welding cable purchased on eBay from coppercableman. This is a high quality cable with an inner liner.

TRYSTAR Welding Cable

The cables from the controller to the motor are 4/0 AWG welding cable covered with copper braid shielding and orange sleeve. The shielding is from KC Electronics. Wire braid is commonly available in the sizes and types described in the U.S. Government Defense Supply Center Commercial Item Description A-A-59569PDF. The sleeve is PET Expandable Braided Sleeving from Electriduct.

shielded cable

Lug Connectors

Standard grade lugs for 2/0 AWG and 4/0 AWG are thin with not much cross sectional area compared to the cable. Those with 1/2in stud hole are particularly insubstantial around the stud hole.

Lug Connectors

I found good heavy duty lugs at the sites listed below.

Strain Relief

For strain relief on 2/0 AWG cable, I use Lapp USA S1121 SKINTOP SL/SLR. These prevent the cable from moving, and seal the hole from moisture and noise.

Strain Relief

A bi-metal hole saw works well to make holes for the strain relief, but leaves a pretty ragged hole in the sheet metal. It cleans up nicely with a large step bit.

Step Bit

Conduit

I used SharkBite U870O100 3/4-inch PEX tubing as conduit to protect and support the power cables running under the car back to front. It is very tough material, with a good balance between flexibility and stiffness. The inside diameter is 0.650in, just barely large enough for the 2/0 AWG cable.

PEX Conduit PEX Conduit

For bends too tight for the PEX, I used flexible metal conduit, painted orange.

Flex Conduit

Fuse

A Ferraz Shawmut A30QS500-4 high voltage fuse is located between the two battery packs, just behind the rear seat, on a block of wood. Opening the rear seat center arm rest provides access. A clear polycarbonate shield keeps hands off.

Ferraz Shawmut A30QS500-4 Fuse Fuse

Disconnect Switch

A Guest Model 2304A switch provides a way to disconnect the high voltage circuit. This switch is rated at 600A continuous, 1000A momentary.

Guest 2304A Disconnect switch