The California Air Resources Board (CARB) postponed the "Zero Emission
Vehicle" mandate for 3 years if the car companies would make a "good faith" effort to market EVs. "By introducing its electric vehicle in May 1997, Honda is addressing
the memorandum of agreement with ...CARB...a year early. This agreement establishes a technology development partnership
between the board and Honda...CARB has established partnerships with seven auto manufacturers." (AHM News,
5-97)
Why is there a Honda EV+? Perhaps we have GM to thank for bringing out the "Impact" and then the EV1.
But don't forget the real reason: the ZEV mandate and CARB.
In the early 1900s, autos had many enemies. Skeptics shouted "get a horse!". For a while, to drive an
auto in England you had to pay someone to walk in front of you with a lantern. The oil interests seem similarly
threatened by EVs, because EV usage "threatens" to reduce our dependence on the gasoline pump.
Perhaps for this reason, there is the 1996 NEC regulation "625" which requires that any EV be charged
from a wall-mounted, UL-approved box. Instead of just plugging in the EV to charge it, you are supposed to use
only so-called "charging stations" which cost between $2,000 and $4,000. The most "advanced"
models actually talk to you. This ignores the experience of the RV industry, which uses STANDARD
OUTDOOR plugs, most of the rest of the world, which plugs in ALMOST ALL APPLIANCES to "220" plugs,
and the fact that hair dryers, toasters, and other household implements are far more dangerous than plugging in
a well-designed 220 plug. And gasoline fires and explosions have caused far more deaths and injuries than any sort
of electrical plug problem
It is to be hoped that these expensive and complicated obstacles will eventually go the way of the man walking
in front of the car with a lantern, and someday the car companies will allow you to plug into any "220"
(actually 208-240) plug to charge up the car.
Meanwhile, you are only supposed to charge using a "charging station" at your home or at
a public place. In practice, this means that you are limited to a 55 mile radius from your house (55 miles out,
and 55 miles back) unless you know in advance of a working public or private "charging station". Is this
done for safety reasons, or to control the proliferation of EVs?
Charging the car while shopping, seeing a movie, etc., is called "opportunity charging". There are currently
two competing and incompatable standards for "charging stations": the GM "inductive" charger
(for the EV1) and the Honda "conductive" charger. At this time there are many more public GM EV1 sites.
The EV1 users have lists of their charging sites, and for opportunity charging we also provide a list of known
public EV+ charging sites. For example, LAX has 10 free parking EV charging stalls near terminal one, and the Getty
Museum is supposed to be installing one. There are funds for many stores and other public places to install charging
stations, but which kind? Or both?
Charging an electric car is actually very simple. Since there is no "memory effect", you can charge it
every day when the EV+ is driven home and parked in the garage. After turning off the car, the driver
plugs the EV+ in with a special "avcon" adapter. The car has an on-board automatic battery
charger, which shuts off several hours later when the car is fully charged.
The Honda gear consists of an "AVCON" plug (which plugs into the car), a long 220 cord, and a specialized
plug which plugs in only to the CCD. The AVCON plug is O.K.--you just need a converter-adapter from
the specialized plug they provide to a household 220 plug (e.g., a household dryer outlet), or an ancient "hubbell"
plug at DWP.
If you charge from a normal "220" socket, the Honda recommended way is to carry a portable Charging device.
It does what is required -- isolates the "communication" signal from the "neutral" line on
the vehicle side, and connects that to neutral on the 220 side. Wall 220 neutral is not connected to anything.
This removes the possibility of neutral voltage spikes.
If you have a Time of Use (TOU) meter, Edison-EV supplies a timer which turns the power on during off-hours. Current
off-hours electricity is priced at the rate of 4 cents per kwh. So to fully charge the EV+'s 26.2 kwh costs about
$1.04. Since 26.2 kwh carries us 100-137 miles, the cost per mile is about one cent.
To compare, the energy in a gallon of gasoline is equivalent to 33 kwh of electricity, so we use less than the
equivalent of one gallon of gas to go our 100 to 137 miles. And, we could power from roof-mounted solar cells.
The Honda charges at only 4.2 kw. The Honda's NiMH batteries hold 26.2 kwh, so it takes about 4-8 hours to fully
charge it, depending on the original discharge state. In adddition, there is a "conditioning cycle" which
takes 1-2 hours, and which may be very important to battery well being. The consumption of electricity (as measured
at the meter) is up to 40% higher than the energy which is actually received and stored in the battery.
When Honda uses a larger capacity on-board charger, it will take less time. With a number of relatively simple
improvements, the EV+ would be even more practical. Energy efficiency is critical for an EV because of battery
limitations and also because of the rate at which an EV is charged is limited by the electrical delivery infrastructure.
The emerging standard for EV charging is 220 VAC (+/- 10%) at slightly less than 7 Kw, which requires a dedicated
circuit of 7000/240, or 30 Amps. The current EV+ charger operates at only 4.2 kw. Increasing the on-board charger
to 7Kw would make the car much more practical since "opportunity charging" would be much faster--we could
get up to 25% of a full charge (28 miles of driving) in one hour of charging.
The 4.2 kw charger is at most only 90% efficient, and then there is the conditioning cycle at the end of the charge.
Thus a 100% charge would take over 8 hours. Actual charging time in most cases is only 2-4 hours, because usually
the car is partially full.
The GM EV1, by contrast, has a 16 kwh battery and a 6.6 kw charger. It can therefore be charged in 2-3 hours, and
can get a useful charge in an hour. The EV+ gets much better range, but the EV1 can be charged faster.
Many people would say that range and recharging are major limitations of EVs. These issues could be resolved with
fast charging. One solution is to have a high-power battery charger at locations like gas stations. A 100 kw charger
could refuel a car with a 20 kwh battery in 12 minutes, enabling it to go another 100 miles. Off-board chargers
have three problems: they are very expensive, they require a very large cable, and they have to be able to recognize
various battery types and sizes. Another solution would be to use the EV's motor controller as the charger. Since
the motor controller is already sized for three-phase, 50-100 kw (EV+ vs. EV1), a 277 or 345 volt system (standard
in North America) would be able to supply this level of power at 40-100 amps. A standard 60 amp, 345vac, 3 phase
connection would provide 60 kw, which could be supplied by a cord much smaller than the hose of a gas pump, and
could recharge a 20 kwh battery in 20 minutes.
"SMART PLUG" DETAILS
The EV+ sends a low-voltage pilot communication signal on the "neutral" line. When plugged into the "Home
Connecting Device" (HCD) box, this signal is received and decoded by a circuit in the HCD. The safety circuit
turns on a relay to apply the line power to the car as long as the HCD continues to receive the signal from the
car. |