April 29, 2007 by Rob.

I got the final cuts and fitting for the boxes taken care of today.  I’m trying to coordinate a time to visit Paul’s house to get the last welds done.

One small surprise: I noticed that the front engine support was not bolted while I was marking the supports for the front box.  The transmission and engine were hanging from the back support!  I had to pully up the engine about 1″ to get the screws to mate.  It’s amazing to think how a couple of little screws really holds all these pieces together.

Posted in Storyline, Planning | 1 Comment »

April 29, 2007 by Rob.

If your an EV newbie, then you probably are wondering why an electric car with twelve 12 volt batteries needs a converter to create 12 volts DC electricity.
The answer is Zen: the main (aka traction) batteries need balance to have a long life.  When the traction batteries are in series and need to be discharged in an even way.  Performance of batteries in series is limited by the performance of the weakest cell.    Drawing more power from one battery to run the car electronics effectively degrades the entire pack.

The solution is to draw 12 volt auxiliary power (lights, wipers, radio, etc) from a supply that draws evenly from the full traction back.  The supply must convert from the 144 VDC traction pack down to 12 VDC: that is our DC-DC converter’s job.

Posted in EV Tech | 1 Comment »