On Sep 13, 2009, at 3:08 PM, [email protected] wrote:
While browsing the net looking for info on their battery technology
I noticed
that they plan to build a network of quick charging stations.
Otherwise one is
obviously stuck with a slow charge using normal household power.
However IMO the
latter would be quite acceptable to many people, after all the car
usually sits
in the garage for many hours every night doing nothing anyway
(driver sleeps =
car recharges, and everyone has to sleep sometime).
The specs state or imply the e6 uses about 18 kWh per 100 km, has a
range of 400 km, and can "quick charge" to 50 percent of capacity in
10 minutes.
The e6 thus requires 72 kWh for a complete fill up. At their fill
stations this would take at least 20 minutes plus queue time for a
fill up, given 50 percent of capacity charge in 10 minutes. This
would be intolerable for many people. Charging stations would have
to have a lot more area than current filling stations to support the
same traffic. The quick charging "premium" would have to be fairly
high for the charging stations to break even.
Charging the full 72 kWh at the 120 V 10 A home outlet they suggest,
i.e. a 1.2 kW outlet, what they call a "normal charge", would take 60
hours, and to half capacity 30 hours - not too effective for a 5 day
a week commuter who travels over 200 miles a day, which is not
unusual in various California or New York City areas.
Using the biggest socket typically available in the US, a 240 V 50 A
socket, a 12 kWh socket, charging full capacity would take 6 hours,
which is feasible. However, for a typical home with a 100 amp
service, this would take 50 percent of the home's current capacity
for one car and preclude use of home appliances like an electric
dryer or electric oven, which also take a similar socket, during the
charging period. A family with two or three commuters and a 100 amp
service would likely require a major home capacity upgrade. The
alternative is some home form of energy storing and quick charging
station.
The ad conveniently ignores some of these implications. That is not
to say such a car would not have great utility for some people. I am
glad to see that. However, the advertising appears at minimum to
create false expectations, and that should be fixed, for the sake of
potential investors and customers, and the company's own image. It
taints an otherwise apparently good thing.
Best regards,
Horace Heffner
http://www.mtaonline.net/~hheffner/
