Public Debut…and more lessons learned

On Saturday, July 10 was the Portland EV Awareness Day at Pioneer Square in the heart of Portland.  I took the Fastback and showed it to the world.  There were lots of cool cars to see, but still many people stopped and asked about our car.  One of the OEVA (Oregon Electric Vehicle Association) members took a bunch of pictures: http://www.flickr.com/photos/darkstarpdx/sets/72157624467961958/.  It was a hot sunny day and I wish I’d worn sunscreen and a hat…

I cleaned the car really carefully (with a toothbrush in spots) and put a nice wax on it so it would look pretty.  Jeanette came by and took some pictures.

At the OEVA Show

At the OEVA Show

I also got to take a close look at the other conversion that people had done, and talk to them about their experiences.  I learned a few things about how to properly mount batteries, and other sources for parts and systems.

My design for the battery boxes has a few flaws.  If you are considering a conversion, please think hard about access to the components after installation.  In my case, I should have done two major things differently.

Mount the batteries on shelves, not in boxes.  The batteries come with clamps for locking them into compressed blocks.  I tossed these and put the batteries into boxes instead.  In hindsight, this was dumb because: (1) it’s very hard to get a single battery out; (2) it forces you to do your battery wiring with the batteries in the boxes; and (3) the boxes are heavy.  What I should have done was use shelves with a 1″ lip.  I then could have bound the batteries into blocks of four or five and simply dropped them onto the shelves once they were wired.  A simple hold-down bracket would complete the job.

Use a modular design. In the upper rear engine compartment, my design has one big box/shelf combination that holds 24 batteries and the controller.  I should have designed this as three smaller units.  Having it in one piece caused two big issues: (1) I cannot work on a drive-train component such as the clutch or transmission without removing the entire rear setup; (2) that single piece is so heavy that I cannot easily handle it.  To give an example, to replace one battery in my rear-most bank, I would have to remove all the rear battery boxes, the motor mount, the motor and transmission (as a unit) and the motor controller – and then pull out the very heavy one-piece box/shelf combination.  This would literally take all day, involve using several jacks, and risk damaging things that are working fine.  It’s such a daunting task that I might rather leave a bad battery installed and simply wire around it.

When you design your conversion, keep everything small and manageable.  Your design should allow you to remove any battery block without removing anything else.  If no more than five batteries are treated as single unit, your heaviest component will be only 40 pounds.  If it’s easy to access the motor, you’ll then be able to work on your clutch without disassembling half the car.  Trust me – you’ll be glad.

As an update, my replacement BMS components have arrived.  With luck, I may be able to complete the installation next weekend.

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