Wednesday, June 30, 2010

First Day Drive Report

The first day on the road was nice in many ways, but had a few drawbacks that I'll discuss in a moment.

The car is quieter than ever. The new vacuum pump seems to have two stages. The first stage, and loud one, seems to draw the vacuum down pretty quick, but then it switches to a different mode where it becomes much quieter and to finish the job. It's important to note that when I say "loud stage", that is relative. It is still 1/3 as loud as the old pump. The nice thing is that it never seems to go all the way back to the first stage in normal driving. It just kicks in with the second stage when I hit the brakes. It's so quiet, I can't hear it in the car. I can feel it in the floor, because it's mounted very near my feet, but I can't hear it at all. I couldn't be happier with the new pump.

The drive line is beautiful. There is no wobble, which I expected, but it's actually smoother than before. I'm not sure if this is due to the fact that the motor is better balanced than before, or because the flywheel is absolutely balanced now. My bet is on the flywheel. In either case, it's great!

On the very first drive, I pulled into a local shopping center, and a mother was waiting to cross the street with her little girl. They paused and waited for me to pass, and I parked near by. The mother then told me that her daughter thought my car was very pretty. I thanked her and told them that it was also electric. The mother stopped dead in her tracks and said "You're kidding." "Nope!" I replied. She simply said that it was cool and amazing. A nice little interaction.

Now for the rough bits. Driving in Phoenix, in the summer time, at 1:30 in the afternoon, with out AC sucks. There is no other way to put it and no way around it. It was 110°F in my back yard before I left, which meant it was easily 115°F on the black top. It takes almost no time at all for a person to get really sick of that.

Apparently, the Zilla does not like it either. Towards the end of the trip, I noticed the "Check Engine" light flashing slowly. While I can't say with certainty that it was caused by high temperatures, based on a number of factors at the time, it certainly seemed it. I didn't have a chance to get the error codes off the hairball before they'd been pushed away by different ones (I was doing a little experimenting). But I did put my hand on the controller to check and found that it was too hot to leave my hand on it. I measured it with an infra-red thermometer and found it was a 126°F. I verified the pump for the water cooler was working and the fans mounted to the small radiator were spinning. All is working, it's just too damned hot.

Sadly, adding AC to the system is only going to make things worse. I have no where to put the radiator for the Zilla except for behind the condenser for the AC system. So if that starts spewing out heated air from the AC system, the Zilla will over heat for sure.

The DC to DC converters continue to run their fans non-stop. The ambient air temperature, coupled with the heat they generate while operating must be above the temperature threshold. I'm not sure I can do anything about this. I'm going to prop a fan on a chair and point it straight into the back of the trunk. If they shut off, I know I simply need to find a better way of circulating air through there. If they don't, I'm not quite sure what I'll do. I let them run for 12 hours and found the fans and the DC to DC controllers sucked a full 500 W/hours from the main pack.

I'm still working on getting data on which will be the best way to go with the 12V system. Should I disconnect the DC to DC converters when the car is off, or the SLI battery? I have two pieces of data now. The one I mentioned in the last paragraph, though it's important to note that this was with the 12V SLI battery disconnected. If I shut down the DC to DC converters and let the battery handle the load, the car draws off only 44 W/hours. That tells me two things. One, at first glance relying on the SLI battery would seem to be the way to go; and second, these Iota DC to DC converters are energy hogs! I have more data to gather though before I make my final decision, and I'll share that later.


Len said...

Hi Tim,
glad you are back on the road. Guess you were unlucky with regards to the Motor problem. Nearly 2800 ev miles, so far so good, not even one hitch. As for the Iota DC/DC converter think that you need to re wire the system. I have only one DC/DC converter and it switches on only when I turn the ignition on. I never had any problems (my ev is 11 months old) I work 2 mins away from home so I dont use my ev mornings, I only use it in the evening with the lights on however I never had any problems with the auxilliary battery.


Tim Catellier said...

Thanks for the post Len. I think you're right about setting up the Iotas so they are on only when the ignition is on. That's the way I'm leaning.