Archive for April 2010

Nearing the Home Stretch

April 12, 2010

The battery charger arrived this week, after waiting 7-1/2 months.  The car is running, but without a charger I don’t dare drive it far.  So this is a big hump to get over.

The charger is a black metal box 14″ square and 6″ deep, weighing 35 pounds.  The top of it has two fans set amid a field of cooling fins.  The instructions that came with it say to mount it vertically, with the flat horizontal position called “marginal”.   Surely having the cooling fins on top with the fans blowing upwards cannot hurt the unit’s cooling – in fact it should be better than a vertical mount with the fins facing sideways.  So I presume that the “marginal” issue is one of impact shock – there must be circuit boards inside that could crack if you hit a pothole or curb.  Circuit boards are stronger on edge than laying flat.

Long story short – there is no place to mount the charger vertically in the Fastback.  So I had to mount it flat.  To compensate, I added shock mounts.  These are soft-rubber chair leg tips with a hole drilled through the center.  This lets the charger bounce slightly, and should absorb some energy from a hard impact.

The charger fits perfectly where I always intended it to go – inside the former gas tank.

Charger in the gas tank

The cord on the left goes to the wall outlet (more on that later).  The one on the right has three leads: two to the main battery pack (positive and negative) and one small wire to go to the charger interlock relay.  This relay prevents the motor from starting if the charger has AC power – so you don’t drive off while still plugged in.  Unfortunately, the relay that came in my kit has two leads for this function, but the charger only has one.  I have a query out to Electro Automotive about resolving this – we will see if they respond.

Since the charger vents upwards, I made a hole in the trunk liner to compensate.

Trunk liner mod

The charger wants 240V AC power, but it will run on 110V.  Since we don’t have a  240V outlet handy, I made up an extension cord with a 240V plug on one end and 110V on the other.  When I plugged it it, the charger started and went through its startup sequence.  Unfortunately, when it then kicked in to start charging, it popped the breaker in the house.  Thinking, I may have messed up the cord, I reversed the polarity but got the same result.  So, I’ll be calling an electrician on Monday to come install a 240V outlet.  Note to anyone else doing an EV conversion – get a 240V outlet installed on your house if you don’t have one near your parking spot.

Beyond the charger, I was determined to finish off all the other little things that have been undone.  I got a new, smaller 12V accessory battery.

This battery is about 1/3 the size of a standard car battery and weighs a lot less.  Since I don’t need a huge jolt for a starter, this will do the job handily.  Plus it makes space for the DC/DC converter, which has yet to arrive.  This is under the passenger side rear seat.

The other wiring is all finished, except for the BMS.  The guages are connected and all the relays populated.  The relays and BMS are under the driver’s side rear seat and look like this.

Rat's Nest

There is even a USB connector in there, for connecting the controller or BMS to a laptop.  It’s not really as bad as it looks, everything is labeled and documented.  Part of this wiring job were the dashboard guages.  They’re now all connected and the wires taped and tucked away.  With that finished, I glued all the carpet back in place.

Dashboard Wired

A while ago, I mentioned the fusible links in the main battery pack.  Well, today I mounted them permanently with Velcro-style connectors so they won’t accidentally touch something metal.  While I was at it, I took a picture so you can see what one looks like.

A Fusible Link

The car is riding low in the back, so I tried out the airshocks.  Here is a before picture, with the rubber strip on the bumper 17″ from the ground.

Ride Level with Airshocks at 40 psi

I connected my bicycle pump, which read 40 psi.  After six strokes, it was up to 140 psi, and the ride height was 18-1/2″.  This is slightly higher than the original Fastback, reducing the risk of scraping the battery boxes.

Ride Height with the Airshocks at 140 psi

On to some cosmetics.  I put the cabin back together and cleaned it, stripped and painted the engine compartment cover, and gave the car a good washing – its first since August.

Trunk cleaned up

Cabin Cleanup

Last task for this weekend was the “fuel” inlet.  The Fastback has a little door covering the gas cap.  With the pipes removed, there is a 4″ hole  behind this door.  The battery charger plug is only 2″, so I needed to make the gas tank hole smaller, plus shorten the charger wire to suit.  Home Depot to the rescue.  A pair of metal faceplates for electric dryer outlets supply the correct size of hole.  I got some tin snips to cut them into rough circles (they are square).  One plate goes inside, the other outside and they are screwed together.

Big Hole Made Smaller

Then the cord gets threaded through, cut to length, and attached to the weatherproof plug (designed for boats).  With the plug in the hole, the conduit bushing screws onto the back, tightening the entire thing.

Plug in place

So this week will be taken with calling an electrician, going to DMV for license plates (and a new driver’s license while I’m there), putting on the new tires, and nagging Electro Automotive about the charger wiring discrepancy and the still-missing DC/DC converter.  The last task for the weekend was the easiest and most fun – applying the “brag”.

Yes it is!