[ausev] Fwd: EV

[Christopher Robison]

On Sat, June 16, 2007 7:07 pm, Gil Dawson wrote:
> Below is a message from my partner's brother who lives in Austin with
> a challenge for us EV enthusiasts.  He has a Porche been sitting in
> his parents' garage for years, and apparently he's done some
> homework.  Before I write him back, I thought I'd ask you guys for
> some suggestions.   Any comments will be appreciated.

Tell him if he's interested in doing this, he should join the group and
ask his questions here.  I'm guessing he's been reading the wrong stuff,
and/or talking to the wrong people. Much of what concerns him about the EV
marketplace hasn't really been relevant for years.  I'll respond below,
inline:


> At 2:45 P -0500 6/14/07, Beau Eccles wrote:
>
> Okay, it's time for me to admit that I've spent an inordinate amount of
> time lately thinking about EV conversion of an ICE vehicle.  At first
> blush the conversion of the Porsche 914 seemed like a great way to go,
> but then the unfortunate aspects of the donor vehicle push me away.
> Sure, the mid engine design of the car makes room in the front and back
> of the car for putting in batteries, but the car is unibody steel and is

This car is actually a good candidate for conversion, given the kit he
mentions later, and also just the broad experience of others who have
converted them, and wide parts availability. The biggest caveat with doing
a Porsche 914 conversion is actually the condition of the car itself. It's
pretty hard to find them without structurally compromising rust; if his
still has a good strong body, I think it would make a good conversion.


> so much heavier than any other two seat vehicle that has been on the
> market in decades that an insane amount of energy is bled into pushing
> it around.

Actually, weight does make acceleration less efficient, but it's not
meaningful when cruising at a steady speed. Drag coefficient also plays a
part, and given the 914's small frontal area, I'd say it's not as gloom
and doom as he thinks. I doubt the kit would have been as popular if the
watthours per mile were "insane".


>  Furthermore, the conversion kit for the 914 is through a
> company that is reported to be taking two years to deliver its orders.

I've heard some comments about Electro Automotive's timeliness and
responsiveness lately that seem pretty disappointing. However I've also
heard that their quality is very good. Having helped Erik install his EA
kit for his Cabriolet, it looks like they've thought things through pretty
well, and installation is generally pretty painless. The difficulties with
the Cabriolet were mostly from the differences from the Rabbit, for which
the kit was really designed.  At any rate, I haven't heard anyone claiming
"2 years" ...  is he exaggerating, or has he actually heard that?


> The ever-shifting battery landscape and dearth of dedicated EV engines
> is also disturbing.

I don't know what "dearth" he is referring to.  Is he expecting dozens of
different kinds?  Mainly, if you're going with DC, you have sizes from
6.7" to 13", and these will be applicable to anything from motorcycles and
trikes up to full size trucks and SUVs (though the larger vehicles are
difficult to convert for other reasons). Small cars like a Geo Metro or
Honda Civic would do well with an 8" motor. A larger vehicle or one
wanting a little more torque might use a 9". Farver's MR2 uses an 11" and
the performance rocks.

> Conversion blogs show aggravated converters going
> from lead acid to NiMH to LiH, and still not being happy with the
> results.

Those who were not happy with lithium ion were *screwed* by a chinese
company called ThunderSky that sold them used, spent cells. In a
relatively well-known incident a few years ago which is still being
discussed on the EVDL today, a bunch of people put together a big order
for these cells and took the plunge, and then realized that they didn't
get the advertised capacity.

In general though, for people without really deep pockets, we're limited
to lead acid. Within that realm you can get all the performance you want
to pay for, the only real limitation is range.


  There also appears to be no standard for what type of motor is
> the best in power usage/torque/and low to high-end performance mix

Just as there isn't a single gasoline engine that is best in these
features for all cars. The "right motor" choice depends on the particular
car, and the owner's desires with respect to price, performance, quality,
maintenance, etc.

> - nor
> any centralized place that describes the landscape of available motors.

For DC motors, there's Advanced DC and Netgain Warp motors.  For AC
motors, there's Metric Mind's imported european motors, and Azure
(Solectria).  There are other choices, but these are the ones that cover
90% of conversions done today.

> One guy will use the motor for landing gear extension on a jumbo jet to
> convert a VW Jetta, the next a cooling fan for an 18 wheeler.

No one would do a conversion with either of these motors; they're way too
small. Aircraft starter/generators have been popular, but mostly their use
in conversions has ended due to EV-specific choices such as the above.
Every once in a while you'll hear about some cheapskate using one of these
because it was available for cheap. Usually the results are disappointing.


> As for the weight/drag properties of the donor vehicle, if you actually
> want the thing to see highway speeds then the conventional car design
> doesn't appear to be the way to go.

I don't know why he says this.

  There was a very cool
> motorcycle-based, tandem seated  "autocycle" built for a few years in
> the late 80s that had a 900 pound weight that might be a good candidate
> for EV conversion, but I don't understand why there doesn't appear to be
> any standardized EV powerplant (W batteries + X converter + Y controller
> + z motor = 50hp)

In the DC world, motors and controllers are sold separately. In the AC
world where they're sold together, you do indeed get a powerplant package
with a rated horsepower, assuming the highest rated pack voltage is used.
Batteries aren't part of the package because they're a perishable,
replaceable item that's heavy and hard to ship. And no matter what system
you're using, peak output horsepower will depend on the voltage of the
pack used, which is often determined by how many batteries you can fit in
the car.


  I'm disturbed by the persistence of NEVs being
> the only EVs available and I don't want a golf cart.

A lot of us are pretty disturbed about it too.  Fortunately, there will be
other options on the market soon.  At the moment the EVs on the market
(Tesla, Tango, Ebox, Wrightspeed, Fetish) are not affordable to most
people. Phoenix's SUT and Tesla's lower-price offering, while not cheap,
will be in an acceptable range for more people. The major manufacturers
decided they did not want to be involved in producing EVs. So for the time
being, it's up to smaller players to fill the gap. Smaller companies have
smaller production capacities, and so prices will be higher and volumes
lower, for some time to come.

On the other side of the coin, there are convesion shops opening up all
over the country these days, including one in Austin...   :o)



-- 
Christopher Robison
chris at ohmbre.org
http://ohmbre.org          <-- 1999 Isuzu Hombre + Z2K + Warp13!