Wednesday, August 8, 2007

Day 8 - Hump Day!

Another full day of wiring and battery box installation! This time I've grouped the photos by topic.

Low-Voltage Wiring and Auxiliary Battery

The DC-DC converter (left) and the onboard battery charger (right) fit beautifully under the driver's seat. The DC-DC converter helps charge the auxiliary battery (12V) with power from the traction battery array (120V) .

Speaking of the auxiliary battery, Dan recommended the Optima 750U, a rugged, maintenance-free, deep-cycle 12-volt battery that fits under the Vanagon passenger seat (where the regular 12-volt auto battery was formerly housed). A regular 12-volt battery isn't designed to be drained deeply -- it is normally only called upon to assist in starting the engine, and is then recharged by the alternator. The 12-volt in an EV, however, powers everything in the van besides the motor: heat, lights, windshield wipers, turn signals, and even the controller that issues speed commands to the electric motor. Makes sense to get a top-notch one.

Paul and Dan work on wiring the dashboard -- interesting access points in a Vanagon!

Dan really knows his way around the many wires inside the dashboard ...

here you can see him double-tasking.

Conduit hose neatly bundles the dashboard wiring. Barry kindly donated some lengths of yellow and red hose before he left for his eye surgery.

Afshin is under the van bundling wire -- he hates spaghetti!

The wires are all carefully labeled for future maintenance and trouble-shooting. Dan brought in a labelmaker that made short work of that job.

Wiring also extended to the rear. Above is the thermo sensor attached to the motor -- this will light up the old oil pressure warning light on the dashboard if the motor gets too hot.

The controller has been wired to the potbox and one of the contactor relays has been set up.

Paul is RTFMing. The wiring diagrams he's consulting are a part of EVAmerica's conversion kit.

Main Circuit-breaker

This is a temporary fix -- the supplier will replace the circuit breaker next week -- but we have a functioning switch now ...

thanks to Mike and the miracle of epoxy.


NMTCC has a partnership with Hunter Engineering Company, which manufactures machines like the state-of-the-art tire balancer pictured above -- and Doug of Hunter just happened to be in yesterday to demonstrate the machine's capabilities on my new Hankook RA08 185R14 All Season Radials.

Above, the tire pressure tests out.

The road-force balancer simulates the actual weight of the car on the tires, allowing the operator to test under load conditions.

The students at NMTCC are fortunate to have access to such high-tech equipment, which Hunter loans them in return for using the space as a training facility.

Press Coverage

A reporter and photographer from the Lansdale Reporter came to cover the workshop -- Catherine Meredith from the Quakertown Morning Call dropped by and took some pictures earlier in the week.

Mike is being interviewed by journalist Mark Merotta, who wrote an article on this project earlier in the year when the vehicle was having its engine removed by Bill's automotive technology students.

Battery Boxes

They've started to load the batteries into the boxes.

Each one of these batteries weighs 63 pounds.

Larry had to fabricate a long drill bit to install them.

Bill is under the van as Larry drills the holes ...

and Kevin is cutting long bolts to size with a Sawzall.

Those long bolts will slide through these square interlocking components to secure the two-part battery racks to each other and to the vehicle frame. Dan engineered an ingenious solution to the riddle of how to get racks into the battery boxes, since it was only post-box-fabrication that Bill decided that he didn't trust the boxes alone to secure the batteries.

Did I mention that next time around, we will have the battery boxes and racks designed and fabricated ahead of time?!

Here you can see the black overlaps of the racks, holding the batteries securely in the boxes.

Here's an under-the-van view of the rectangular washers Larry was fabricating yesterday. The bolts secure the battery rack/box combination securely to the frame of the van. Essentially the boxes and racks are now integral to the vehicle structure -- which is crucial in the event of an accident. As Bill keeps saying, "We don't want these batteries to turn into Unidentified Flying Objects!" Most EV conversions will locate batteries in the trunk) or in or under the bed of a truck), but since in the Vanagon they're in the passenger compartment, this is a particularly important safety issue.

Despite Bill's efforts to keep us focused on housekeeping, all our work spaces end up looking like this.

Once ventilation holes are drilled in the battery boxes to release any hydrogen that builds up during charging, the class will be ready to move on to high-voltage wiring and testing the van's systems. We hope to be rolling and trouble-shooting Thursday afternoon! Stay tuned!

No comments: