Thursday, February 15, 2007

On the road!

My maiden voyage was a success and there was remarkably little that went wrong on the 46 mile round trip journey from Woodinville to Everett to the SEVA meeting in the newly electrified Saturn. We set off in the car for the 23 mile journey with myself driving, Dave riding co-pilot and the designer of the prototype E-Gauge, Bruce Sherry, driving behind us in case we had technical difficulties. We rolled out on to Woodinville-Duvall road with no problems, accelerating to speed, though I kept it at about 5 miles below the speed limit (according to Bruce) since the speedometer isn't working. There was little need to use the speedometer on the freeway since it was typical stop and go traffic on northbound 405. Using the E-gauge we measured a burn-rate of 2.1 Amp Hours per mile, or 49.7 total Amp hours. I don't have the stats on the T-875, but am guessing we have somewhere around 90 total amp hours available. Since we were well over 50% discharged we plugged in when we reached the SEVA meeting at Pacific Battery. The prospect of waiting 5 hours to get fully charged was thankfully short-lived when the truck that had dibs on the 220 outlet popped the breakers every time it was plugged in. We took over the 220 outlet and had the Saturn charged in about 2 hours. The SEVA meeting was great, we pulled the Saturn in the warehouse and opened the hood and I spent most of the 3 hour meeting explaining the various parts of the car. We then packed things up and headed home, doing around 60 mph all the way home. The only concern was as we headed up a pretty steep hill at about 20 miles in to the return trip and the car slowed down to probably 20 mph as we hit the top and the volts dropped to almost 100 volts. Things rebounded as the road leveled out and we made it back to Dave's house at a pretty good clip.

I'm still not sure whether I'll be able to make it the 30 miles to Federal Way and back, based on this experiment I know the car runs at between 2.1 and 2.6 amps/hour per mile. Based on the slower trip in rush hour to Everett and the theoretical capacity of 90 amp/hours for the battery pack I should have a range of 35 miles. Assuming a 2.6 amp/hour rate I'm looking at exactly 30 miles, so a lot depends on the the terrain, which has a lot of ups and downs between Tacoma and Federal Way. Things are getting close, a couple more tweaks to the engine mount, some cleanup of the wiring, and fixing the speedometer and the car should be ready to go! Things are getting very exciting!

Monday, February 12, 2007

Getting closer...

I just got off of the phone with Dave Cloud this evening and it looks like the car is pretty close to being finished up. He took her on the maiden voyage this afternoon and the overall test was successful. He has a couple of last minute tweaks to make (the amp meter is not working, some scraping on the axle, and there seems to be an overall lack of power). It sounds like the axle and amp meter may be fixable by tomorrow, which would be great since we'd like to drive it up to the SEVA meeting up in Everett tomorrow. The lack of power is expected since we are using a 400 amp curtis controller instead of the custom controller that is not yet finished but that should give us a lot more power once it is installed.

I'm hopeful that the Curtis controller will get us up to freeway speed and that we can successfully make it from Woodinville to Everett and back. If not, it's going to be a long walk home to Tacoma :)