Tuesday, September 04, 2007
EVing at the Cruise!
Make sure to check out my photobucket: http://www.photobucket.com/albums/cc52/greenflightev
Click on "Mazda EV." More pics of the Cruise, the truck, and the motor rebuild.
I took my EV to the Woodward Dream Cruise in August. Man, talk about weird! An electric vehicle cruising around at an event dedicated to engines, and it still managed to get attention! Who knows how many video cameras and cell phones I'm in. It's amazing. There is definitely interest in this technology, you can't deny that! I drove it for 7 hours at the dream cruise without a recharge, and I still had plenty of voltage left! In fact, the 12 volt accessory battery started running low, when there was plenty of juice left in the traction pack. It was awesome! The Cruise is great for this kind of car. Stick it in first gear and cruise all day! It draws a crowd wherever it goes, especially with my shiny new lettering:
Yeah, nothing garners the public eye quite like LIME GREEN signs on a red truck. The pic doesn't do them justice- they're quite eye-catching.
Anyway, while I'm at it here, I should probably mention a rather important incident: the motor blew up. Well, it didn't exactly blow up, but it went out with quite a bang. I had just pulled out of work when I heard a BANG and the tires started squealing. My first thought was a flat tire, since my truck's not exactly the lightest car on the planet. So I pulled over and got out, looked at everything, kicked all the tires, and found nothing wrong. So, like anyone who fails to use his head would do, I fired it back up. This time, it gets me up to about 25 and then does the same thing. And it wouldn't restart. So after an embarrassing half hour parked in a driveway with the hood up staring blankly at the motor, my dad showed up with a tow strap and pulled me home.
Turns out the insulation (class F- 311 degrees F, if I recall correctly) had melted off the field magnets, and one had shorted to the motor case. Actually, two, and in the worst possible locations- they caused the voltage to bypass almost all of the field coils and interpoles. I believe the insulation melted during the initial test phase, when I was having difficulty with the controller. I tried shifting earlier to get the truck up to speed. Turns out I was just heating up the motor. So- to all you new EV drivers out there- wind it out! I believe the vibration eventually caused the coils to contact the case. I guess that's what I get for buying a cheap motor.
After getting a quote of $1000 to rewind the motor, I decided I wasn't feeling so flush after all. I decided to try and rewind it myself. It's not too difficult- just takes time:
Hopefully in the future I'll be able to write up a detailed description of how this is done. The bottom line, though, is that it worked, and the motor runs great. Not to mention, it now has class H insulation- good through 356 degrees F. I also installed a 12v CPU cooling fan in the endbell to help with cooling- the original fan was near worthless.
I'm currently in the process of installing an electric radiator fan in its place. The motor still gets warm with the CPU fan. Should allow me to push a few more amps through the motor, and get more top speed. I'll try to add some pics to my photobucket later.
Speaking of fans, I now have one installed in my homemade bed cover to vent the batteries. This way I don't have to prop up the bed cover to allow hydrogen to escape. I also have a 12v charger hardwired in under the hood to charge my accessory battery- this thing just gets easier and easier!
Anyway, I have about 700 EV miles on my truck so far, and all I can say is- I LOVE IT! The cost of electricity is nearly negligible, and it is awesome as a commuter and errand-runner. Range has not presented any issues for me. I do notice that I tend to plan a little better, trying to get more things done on one trip, but hey- that's a good thing!