Monday, November 28, 2011

More Exposure

A few weeks ago I took the car to a couple of different events, and I'm finally getting the opportunity to share it.  The optimal word here is "different" as the experiences couldn't have been more different from one another.  The first, was a car show.

People who've been following this blog for a while may remember that last year I was invited to bring the car to General Dynamics for their employee car show.  It's worth noting that I don't work for General Dynamics, but I know someone that does, so really I'm not qualified to be there.  Last year he suggested to the organizers of the event that I come.  They were quite happy to have me there and I was available so I went.  The car was a big hit, and when I was driving out of the parking lot, they told me they'd like me back next year.  I agreed.

Well, mid-October rolled around and they did indeed contact me asking if I would bring the Z3 back for display.  So the first week of November, I drove down to their offices ready to answer all the questions I knew were coming.  Apparently I didn't warrant being placed with the "Premium cars" like last year.  They just lined me up in some random spot on the grid.  If they'd had some foresight, they would have put me next to the Nissan Leaf that showed up, but they didn't. 

It turns out, it really didn't matter where I was lined up.  Eventually, just like last time, there was a crowd around the car.  It's really the perfect venue to show the car.  This is a company full of technically oriented people, many of them engineers.  Each was curious to see the project and how it was done.  Several stepped forward to ask questions, many of them quite good, all picking my brain for details.  There was one guy who was telling me about the car he has and the conversion he's had planned for it for some time.  Hopefully, getting the chance to see a conversion first hand will inspire him to move the process along. 

This was the first chance I've had to show the car with all the new safety systems in place.  Of course by safety systems I mean sheets of Lexan strapped to the top of the batteries.  Still, like I'd said before, you could throw a bucket of wrenches in the engine compartment and there's no way for them to short on anything.  But best of all, there's no way for anyone to get their fingers on anything that could harm them.  They might cut them selves on something if they stick their hand somewhere too tight, but certainly no chance to electrocution.  It was very satisfying knowing that no one could hurt themselves by mistakenly touching something they shouldn't.

All in all it was a very successful event.  I believe several people walked away with a more positive view of EVs. 

The next day I was at an event sponsored by a local group called Gang Plank.  This was set up by another local EV enthusiast who also attended EVCCON in September, Kevin Larsen.  Gang Plank is what I would describe as a co-op for business start ups.  They have work space and meeting spaces available to people who are interested in starting a business but don't have office space available to them.  Once a week they have a brown bag session for a topic the administrators there think might interest their clients.  Kevin worked with them to arrange a brown bag session concerned with converting a car to an EV.  Understandably, Kevin thought it might be a good idea if I came along and gave a short presentation, show the car and answer some questions.

I thought our presentation was informative if not particularly polished.  What surprised me was how supremely uninterested the group seemed to be.  There were perhaps 6 people (out of 35 or so) who bothered to gather in front of the dais we used and most seemed only casually engaged in what we were saying; occasionally someone would look up. Apparently to see if we were still there.  When the question and answer session came up, there were a few good ones, but I found myself answering questions more about EVs in a broader sense rather than the merits or particulars of converting a car.  For instance someone asked me about the true carbon off set of an EV versus a gasoline powered car.  I did my best to answer these questions, but I'm no authority on such matters.  But more than anything the questions betrayed the fact that what we were presenting to them was really a few steps ahead of where they were as a group.  Just the wrong audience for our material.

After the presentation, a few people and I wandered back to where the Z3 was so that they could look it over.  It seemed more like something to pass their time rather than something that really interested them.  The whole time I found myself hoping that the entire endeavor wasn't simply a waste of time.  Everyone was very nice but no one seemed particularly interested.  There was an owner of a Leaf there who was quite engaged, and we chatted for a while, but he's one of the initiated (so to speak).  The whole day stood in such stark contrast to the events at the car show the day before.  I took solace in the fact that if nothing else these people saw a REAL EV that's being used on a daily basis by a REAL person.  Hopefully that will stick with them.

Friday, November 4, 2011

It's An Imperfect World, Screws Fall Out

One of the frustrating things that occurred during this summer's work on the car was that stuff seems to have broken all on it's own.  Through no intervention on my part, at least two items on the car stopped working.  Trust me when I tell you I've been responsible for breaking a number of things related to the car, but I think I'm innocent here.

After I hooked the batteries back up and turned on the new TBS Link-Pro meter, I had to run through a series of menus to set it up properly.  When it came to the prescaler menu, I selected the 1/10 prescaler because that's what I was using for the older Xantrex Link-10.  To my surprise the meter read that my pack voltage was 68.9 volts.  Well that's a bit off as my pack voltage is 160V.  I double checked the meter looking through all the settings and found everything was correct.  Eventually I pulled the meter out and measured the leads coming from the prescaler itself only to find that the leads which should have read 16V, instead read 6.89V.  Well that put the blame solidly on the prescaler, the meter itself is fine.

I checked and the prescaler was hooked up correctly, after all I hadn't changed any of that.  But there was no doubt about it, the prescaler was spitting out the wrong voltage.  I have no idea why it broke, how it broke or when it broke.  All I know is that when I unhooked the batteries in May, it worked, and when I put them back together in September it didn't. 

Not being an expert in electronic circuits, I have no idea how to fix the prescaler.  As far as I'm concerned, I put 160V on two wires that lead to a little box in which some magic happens, and then on the two wires coming out the other side, there's 16V.  Besides, the unit is sealed.  I was left with one option and that is to replace it. 

I got the replacement 1/10 prescaler and thought I'd measure it before I disassembled the dashboard to put it in.  I carefully hooked it up to the positive and negative leads to the 160V system, and to my amazement the other end read 48.3V.  What the hell!?  Now I had two different prescalers, each of which should be working fine, but both spit out completely different and incorrect voltages.  I sent the new one back at which point they evaluated it and said it was fine.  What!?

I'd ordered the part from Evolve Electrics and was working with Justin Dunn.  It turned out that both of us learned something about this prescaler and the TBS meters.  Both the 1/5 and the 1/10 prescalers will read 48V when hooked up to the pack.  It's only after you hook it to the meter does it somehow adjust the voltage and display it properly.  Like I said before, magic.  Neither of us expected that.  By the way, Justin was great to work with.  I feel quite comfortable recommending Evolve Electrics. 

The second thing that seems to have broken while the car was sitting still was the tachometer.  I drove the car around for a couple days after putting it back on the road, and all was well.  But one evening I left my destination to head home, turned on the lights and found that the tachometer's dial didn't light up.  A few moments later I realized it wasn't working at all!   It had been working when I arrived earlier when the lights weren't on.  When I came to a stop light, I turned off the lights and revved the motor.  Sure enough the tach sprang to life and worked perfectly.  It was hovering at about 2000 RPM and I turned the lights back on and the needle froze where it was. 

I have no idea what would cause such strange behavior, but I do know that I didn't touch any of those systems or their wires when I was performing the work this summer.  But then it just got worse.  A couple weeks ago I was accelerating from a light in second gear.  At about 35 MPH I went to shift to fourth and I noticed that the tach read 5000 RPM.  I thought that was odd because 35 MPH in second gear is about 4000 RPM.  I dropped it into fourth and watched the needle come down to about 3000 RPM, which I know is too high for that speed.  Suddenly the needle jerked up to 5000 RPM, then 6500 RPM.  By the time I finished my trip, the tach's needle had moved well beyond the 8000 RPM top of the dial, and was approaching a full lap coming around to 0 again.  Now the tach just jumps around all over the place providing no useful data.  It's just become a distraction.  I believe I'll be unhooking it.

So what the heck happened to these two pieces of equipment while they were sitting still and not being powered over the summer?  I really wish I knew.  The tach I can live without.  I'll probably replace it at some point, but for now, it stays.  Justin sent the prescaler back to me and I popped it in yesterday.  It works just fine and the meter is behaving like I expected.  If you ever end up with the TBS meter and prescaler combo, don't bother taking a voltage measurement from the prescaler itself, it won't be what you expect it should be.  It has to be hooked up to the meter.