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EV First Impressions

This page is a summary of some of my impressions of the car after about 1000 miles of driving. I have put about 1000 miles on the car as of January 12, 2008. The car first ran on Sept. 4th of 2007.

Performance

Top speed and acceleration

I built the car for a 136v battery pack, but ended up installing a 102v pack instead, basically due to a planning goof on my part. See my EV Traction Battery page for more details. Basically the range is unaffected by the lower voltage, but top speed and acceleration are reduced. The car's top speed is about 60 to 65mph, and the acceleration while still pretty good at city street speeds, gets fairly leisurely by the time you are getting up to freeway speed. The situation is tolerable for a while until I can justify either buying the right kind of batteries or (more likely) adding 3 more batteries to a sunken compartement in the trunk. You know, lemons to lemonade: get the performance back up a bit with a higher voltage pack, and add to the range at the same time... Update! see my Range and Performance Upgrade page for details as to how I fixed the performance issues resulting from the 102v battery pack.

Handling

The handling of the car is actually pretty good. While it is undoubtedly heavier feeling that it would have been as a gas car (I never drove it that way) It corners pretty well and doesn't sway, swerve or lean. It feels pretty well balanced front to rear. The EV Suspension System seem to be a good match for the weight of the car. Braking is adequate. It never had, and still doesn't need power steering.

As for driving it, for almost all city and side streets up to 35mph, I just leave it in third gear. No need to put it in neutral to stop. Over 45mph, I use 4th and on long or steep hills I use 2nd. 1st gear is almost unnecessary. Shifting is a bit annoying because the motor takes so long to spin down or up (if you don't rev it) versus a gas motor. For downshifting I could rev the motor a bit once I get a better feel for it. After several months of driving, I'm beginning to wonder if the clutch is sticking or something because it shouldn't be as hard to shift as it is. I will be investigating further.

Systems

Mechanicals

After several months, the car is still doing great here. The motor and transmission sound good, and nothing has been grinding, shaking, or otherwise causing worry. The motor and controller barely get warm even after extended hills or high speed operation. So I think the mechanicals are pretty solid.

Electrical Systems

There were a few early issues I had to deal with, including replacing the DC-DC converter with a different unit that would work on a lower voltage battery pack. This was a direct result of going with a different voltage battery pack than originally planned. The actual electrical system repair I have had to make was to redesign a fuse bracket that melted down due to a poor electrical connection. Other than that, all is golden so far. The EV Traction Circuit has been working well.

My EV Control Electronics for the various contactors, heater, etc. seem to be working well.

The EV Toaster Heater produces only a little heat. It will produce more with a 136v pack. The heat will probably be more noticeable on colder days though. Also, I could try upping the setting on the thermostat since it is adjusted to its lowest possible setting.

The radio quit working recently. Need to look into that. Hardly the fault of being converted to an EV I suspect.

Range

When I first got the car running in September, I ran a 32 mile drive on brand new batteries and I measured about a 50% DOD (depth of discharge) on the batteries. I extrapolated from that to say the car had a 45 mile practical range.

I have yet to try to exceed the 32 mile mark I set back in september, but I regularly drive 25 to 30 miles for my running around town. With that amount of driving, and dead-of-winter cold and dark I am still staying at or above that 50% depth of discharge on the batteries, so even in winter, without battery heaters I am seeing pretty decent range. I figure once summer rolls around again I should be able to comfortably get close to 50 miles of driving range. (Note that lead acid batteries, especially flooded ones, are very sensitive to temperature. They can lose almost half their useful capacity at freezing temperature vs. summer temperatures. This is why a lot of homebuilt EVs incorporate insulated battery boxes and/or battery heaters. I chose not to do this with my car for the sake of simplicity.

At this point I have performed several of the optimizations I planned to do to improve range, but there is still more to do. See my EV Efficiency Improvements page for more details.