Converting your gas car to electric is no shocker...By Shari

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					November/December 1994 Backwoods Home Magazine                                            INDEPENDENT ENERGY




Converting your gas car to electric is no shocker
           By Shari Prange                  what maintenance there is can be done      car has used up its entire capacity, this
                                            easily by the owner.                       charger will bring it back to a full
       he old advertisement said,

T      “Your car is your freedom,” but
       sometimes it feels more like
indentured servitude. Actually, buying
                                              An electric car can simplify your
                                            paperwork, too. If you live in a state
                                            that requires smog inspections, you
                                            don’t have to participate any more.
                                                                                       charge in about 12 hours. Typically,
                                                                                       this means overnight. If the car is only
                                                                                       partially discharged, it will come up
                                                                                       faster.
the car is only the beginning, followed     Once the state classifies your car as        There are also 220 VAC/30 amp
by the registration, insurance, and         “electric” on its main computer, you       chargers available. These will charge
inspections.                                are exempted from smog inspections.        the car in six to eight hours. However,
  Then there’s fuel. It seems like            As a final bonus, an electric car is a   they are more expensive, some of
every time you get into the thing, it’s     pleasure to drive, because it’s so         them are large and heavy, and 220
thirsty. There isn’t a gas station on       smooth and quiet.                          volt power is not as readily available.
every corner any more, and if you                                                        If you want to feed juice to your
need diesel, you may have to hunt           Electric cars today                        charger from a solar array, it will need
even further. This is especially incon-                                                to be a large stationary array. Solar
venient if you enjoy the solitude of          The electric cars available today are    panels on the car itself are not cost
life away from towns and cities.            conversions. A small number are new        effective. Covering the entire roof of
  Of course, you can put in your own        cars converted to electricity by manu-     the car with panels and letting it sit in
fuel tanks at home. However, they can       facturers. These range in price from       full sun all day would only provide
be as much hassle to refill as the car.     $25,000 to $150,000, and are general-      about five miles worth of electricity,
And there are all the regulations about     ly sold to fleets, such as utilities.      at a cost of about $3,000 for the pan-
monitoring the tanks for leaks.               For the average person who wants         els.
  Then there’s maintenance and              an electric car, a more economical
repairs. An acquaintance of mine once       option is to convert a used car, or have
                                            the conversion done by a mechanic.
                                                                                       Batteries
said that you buy an internal combus-
tion car over and over again—one              So just what is involved in convert-       From the charger, the electricity
piece at a time. And the newer cars are     ing a car to electricity? First, you       moves into the batteries. The typical
getting harder and harder for the home      remove everything related to the inter-    conversion has a 96 to 120 volt battery
mechanic to work on.                        nal combustion system: engine,             pack. The size of the pack is con-
                                            exhaust system, fuel system, and cool-     strained by two factors. Any less than
The simple alternative                      ing system.                                96 volts, and the car won’t have ade-
                                              Then you add a charger, battery          quate speed and acceleration to be
  There is another option that can end      pack, speed controller, motor, and a       streetworthy, nor will it have much
your servitude: an electric car.            few other small bits and pieces. Let’s     range. Above 120 volts, compatible
  An electric car simplifies your life in   take a minute to tour a typical conver-    components have not been available
many ways. The most obvious one is          sion, and see what each part does.         (although 144 volt components are
fueling. What can be more convenient                                                   now coming out). Also, the added
than coming home and plugging in the        The charger                                bulk and weight of the extra batteries
car? No muss, no fuss. You don’t                                                       tends to negate the gains in power.
have to go out of your way to find gas        The electricity comes into the car         The batteries most commonly used
or diesel, and you don’t have to deal       through a charger. The car doesn’t         are 6-volt lead acid traction batteries,
with the regulations connected to           care where the electricity originates—     the same kind used in golf carts.
home tanks.                                 a public utility, a small generator, a     Typically, they are rated at 230
  Another beautifully simple aspect of      solar array, or even a wind generator.     amp/hrs, and weigh about 67 lbs.
the electric car is its maintenance—or        The most common chargers use 110         They are 6-volt batteries because there
lack of it. Say goodbye to the auto         VAC (volts alternating current)/20         has not been a suitable 12-volt traction
repair shop and the parts store. An         amps input. These are popular because      battery available until very recently.
electric car needs very little care, and    the charger is small and light, and 110    There are some 12-volt traction batter-
                                            volt power is readily available. If the


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                                                                       November/December 1994 Backwoods Home Magazine


ies now on the market, but they are         Motors                                        Conversions are manual transmis-
too new to know yet what kind of per-                                                   sion cars. The clutch is maintained for
formance they will give.                      From the controller, the electricity      safety reasons, and because it provides
  They are lead acid batteries because      flows to the motor. In the old days,        a much smoother ride.
any other kind of battery, at this point    this might have been an aircraft starter      Why no automatics? There are
in time, suffers from one of two draw-      or generator pressed into service in a      problems with power losses, delayed
backs. Either it is still available only    car. These made great aircraft starters     throttle response, and mismatched
as a laboratory test model, or it is sev-   and generators, but lousy car motors.       shift points in automatics that produce
eral times more costly than lead acid.      They were designed to operate at            inferior performance.
Gel cells require low current charging      much lower voltages and higher rpm.           What about direct drive? Many pro-
to avoid internal damage. Standard          In an automotive application, they          duction cars use direct drive.
chargers commonly available do not          were fragile and highly inefficient.        However, in order to get acceptable
provide the appropriate charging pro-         Fortunately, today there are reliable,    speed and acceleration, they require
file for gel cells.                         efficient motors available that are         battery packs of 300 volts or more.
  Finally, they are traction batteries      manufactured specifically for electric      This puts them out of the reach of the
rather than starting/lights/ignition        cars. The most popular for conver-          average person.
(SLI) or marine batteries. SLI batter-      sions is the series brush DC (direct          From the transmission, the power
ies can provide high current, but can-      current) type motor. This motor oper-       goes to the wheels, just as it did in the
not stand up to repeated deep dis-          ates well in the rpm, voltage, and cur-     gas car. The drive wheels can be front
charges and charges. Marine batteries       rent range of a passenger car. It com-      or rear with equal ease. What is not
can take the charge/discharge cycle,        bines efficiency with affordability,        practical at this time is four-wheel-
but don’t last very well when required      making it very practical for daily dri-     drive, due to the complexity and cost
to provide high current. A traction bat-    ving.                                       involved.
tery is intended to move a vehicle            Permanent magnet motors show up
down the road, and it can handle both       most often in ultralight solar race cars.   Performance
deep discharges and high current            Although they are very efficient, their
draws.                                      efficiency is limited to a narrow rpm         Okay, so here’s this electric car.
                                            band. This makes them suitable for          What can it do? Typical range for a 96
                                            endurance races at a constant speed,        volt sedan is 60 to 80 miles. Some of
Key and throttle                                                                        the high-performance sports car con-
                                            but not for the ups and downs of daily
  Turning the key turns the car “on,”       driving.                                    versions can stretch that to 80 to 100
just like a gas car, but nothing hap-         Brushless DC and AC units are also        miles. These miles are typical daily
pens until you depress the throttle.        available, but at a significantly higher    driving: some stop and go, some free-
Then a main contactor closes and            price. The motor itself may not cost        way, average speed about 40 mph.
electricity flows from the battery pack     more, but the complex control system        The top speed on a typical sedan is
to the speed controller. A potentiome-      it requires is much more expensive.         about 65 mph, and on a sports car it’s
ter, called a potbox, is connected to       These systems are generally only            about 85 mph.
the throttle pedal. It sends a signal to    found in production cars or high-bud-         Night driving is not a problem. A
the controller based on how far the         get, high-performance race cars.            DC/DC converter taps the main bat-
pedal is depressed. The controller            Other exotic motors, like exotic bat-     tery pack for a few amps to charge a
releases energy to the motor in pro-        teries, tend to be unavailable or unaf-     12 volt accessory battery for lights,
portion to the signal from the potbox.      fordable for the average person.            horns, etc.
  Most controllers in conversions                                                         Cold weather is not a problem,
today are sealed solid state units          Adapter & transmission                      either. There are various types of pas-
which are very reliable and durable.                                                    senger compartment heaters available.
They are also very efficient, quiet, and      The motor is mounted to the original      Both the cold temperatures and the
smooth in operation.                        transmission using an adapter.              heater will diminish performance
  The controller operates by “chop-         Typically, this adapter comprises one       somewhat, but probably only about
ping” the voltage from the batteries. It    or two precision-machined aluminum          15%. There are happy electric car dri-
functions like a switch that turns the      plates, and a steel hub. The safest,        vers in Maine, Quebec, Alaska, and
electricity on and off 15,000 times per     most reliable hub type is the taperlock.    even the Yukon.
second. How long each “on” pulse            This will not work loose like a               Can they climb hills? You bet. For
lasts is determined by the throttle         setscrew hub.                               long continuous climbs, or very steep
pedal and the potbox.                                                                   hills, or hills that require freeway


                                                                                                                             55
November/December 1994 Backwoods Home Magazine


speeds, a high-performance conver-            This is the kit for the rugged individ-   conversions of existing gas cars, light
sion is recommended: a light, aerody-       ualist who wants the feeling of accom-      trucks, and vans.
namic body, with a large motor and at       plishment that comes from creating            They tend to use AC drive systems,
least a 120 volt system. For intermit-      the car with his own brain and hands.       direct drive or automatic transmis-
tent climbs of a mile or less on a mild       On the high end, you can buy a com-       sions, and very high voltage packs of
grade at reduced speeds, a typical 96       pletely prefabricated kit for about         unusual batteries. All of this con-
volt sedan is adequate. Climbing hills      $7,000, and add about $750 for batter-      tributes to price tags from $50,000 to
will reduce the car’s range, under          ies and 40 hours of your time. This is      $150,000.
severe conditions (we’re talking actual     the kit for the person who has other          Quite probably, foreign manufactur-
mountains here) by as much as 50%.          outlets for his creativity, and simply      ers will be the first to offer production
  What about going downhill? Can            wants to get the car finished and on        electric cars for the mass market.
that energy be harnessed to recharge        the road.                                   Peugeot and Fiat already offer such
the batteries? This concept is called         Once it’s built, it will save you         cars in Europe. The Japanese and
regenerative braking. Although much         about 60% on operating costs. A con-        Korean manufacturers are also devel-
experimentation has been done on it,        version typically uses about 0.4 kwh        oping mass-market electric cars.
there is not yet a satisfactory system      (kilowatt-hours)/mile of electricity.       Potential prices for these are
available commercially. Some sys-           The only other maintenance expense          unknown, but are likely to be much
tems, like connecting a small alterna-      is replacing the battery pack at about      closer to the $15,000 to $20,000
tor to a second motor shaft, simply         four to five year intervals, and replac-    range.
aren’t very effective. Others are not       ing the motor brushes at 80,000 miles.        Initially, all of these will be electric
compatible with the available motors          There are also various tax benefits       versions of existing gas cars, simply
and controllers. Others are bulky and       available. These change from state to       due to the time and expense required
complex, and have a potential failure       state and from day to day, so check for     to tool up for a completely new chas-
mode of full acceleration (not a good       the current information in your area.       sis. As the market grows to support
thing when you want braking action).                                                    the effort, cars designed from the
  Also, for a great many people,            Electric cars tomorrow                      ground up will appear.
regenerative braking would not fit                                                        Will private conversions continue?
their driving patterns. Most people           In the past four years, public interest   Of course. Americans have a genetic
live up high, and their main downhill       in electric cars has increased enor-        need to modify their cars. The hot rod
stretch comes when they first leave         mously. With the increased public           controller will simply replace the hot
home—and the battery pack is fully          interest has come increased manufac-        rod carburetor.
charged. The ideal application for          turer interest. Where will it go from
                                            here?
regeneration would be a long downhill                                                   Components
in the middle or at the end of the
drive.                                      Major manufacturers                           It seems likely that there will be two
                                                                                        parallel tracks of electric vehicle tech-
                                               The state of California has mandat-      nology for some time. The major man-
Time & money                                ed that in 1998, 2% of the cars offered     ufacturers are concentrating on AC
  What does it cost to convert a car to     for sale must be zero-polluting, and        systems and exotic batteries. Due to
electricity? The cost in dollars is         that number increases to 10% by             the difference in cost, grassroots
inversely proportional to the cost in       2003. All of the major manufacturers        efforts are likely to continue to use
time. On the low end, you can buy a         have electric car programs in progress      DC systems and lead acid batteries.
bare-bones kit for around $4,000, add       in order to meet this mandate.                This is not to say that there will be
another $1,000 or so in batteries and         American manufacturers, while pub-        no improvements. Motors, controllers,
miscellaneous materials, and spend          licly trumpeting their programs, have       and chargers that can handle DC sys-
about 200 hours of your time                been fighting tooth and nail behind the     tems up to 144 volts are now coming
installing it. In this scenario, you will   scenes to overturn the mandate. They        available. Also, as the market
be responsible for designing the com-       are concentrating their reluctant pro-      expands, prices will come down.
ponent layout and designing and fabri-      grams toward supplying electric vehi-         DC motor technology has been
cating things like battery racks and        cles to fleets in the hopes of meeting      around for a long time, and has been
boxes, various mounts and brackets,         the mandate without really having to        refined to the point where efficiency
and a wiring loom. You will also need       address the public market. With the         differences between DC and AC
to make any necessary suspension            exception of the GM Impact, these           motors are negligible. There are not
modifications.                              programs are producing production



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                                                                      November/December 1994 Backwoods Home Magazine


likely to be major breakthroughs in          On one track are the exotic batteries:      New battery designs can accept
DC motors.                                 sodium sulphur, nickel metal hydride,       higher charging currents—briefly—
  Where the improvements will come         silver zinc, lithium polymer, and           without heat problems. New charger
will be in matching the motor to the       more, too numerous to mention. Each         designs accommodate this by pulsing
overall system. There are trade-offs       has its proponents. In fact, the U. S.      the charging current, giving the plates
between rpm and torque, speed and          Advanced Battery Consortium was             a brief rest between pulses. The charg-
efficiency, and many other factors.        formed to examine and sort out these        er may even insert a tiny discharge
With a systems approach, the motor         technologies and develop a better bat-      between charge pulses. This kind of
can be engineered to provide the best      tery to meet the California mandate.        technology is still experimental, but is
match with the controller and the per-     The energy-to-weight goals set by the       expected to be in production within
formance needs of the car.                 USABC eliminate lead acid from con-         four years.
  Controller manufacturers are also        sideration.                                   With pulsed quick charging, the car
looking to match their components            There is considerable debate regard-      would still be charged primarily at
better to the motors and the overall       ing whether any of the exotic tech-         home, overnight. Most people would
systems.                                   nologies can be developed to a mar-         rarely need the quick charge, but when
  The debate in controller technology      ketable stage in time for the mandate,      they did, they could stop at a charging
today revolves around MOSFETs              and whether “marketable” is measured        station and recover up to 80% of the
(metal oxide semiconductor field           by the fleet market or the public mar-      battery’s charge in 15 minutes or less.
effect transistors) and IGBTs (insulat-    ket.                                        (The last 20% of the charge is the
ed gate bipolar transistors, pronounced      On the other hand, there is the           most difficult to do quickly without
igg-bits). These are the pieces that       Advanced Lead Acid Battery                  damaging the battery.)
actually turn the electricity on and off   Consortium. This is a group of lead
inside the controller.                     acid manufacturers who have pooled          The big picture
  IGBT proponents claim higher effi-       their research efforts to show that lead
ciencies. IGBT controllers are also        acid is a more viable immediate alter-        In the immediate future, for the
easier to manufacture, because fewer       native.                                     average person, electric cars will pri-
IGBTs are needed than MOSFETs to             There are a great many advances           marily be conversions using improved
do the same job, and production can        being made in lead acid technology.         versions of traditional DC and lead
be more easily automated.                  These include new grid alloys for           acid technology. Foreign manufactur-
  MOSFET proponents question the           longer life, super-thin plates to mini-     ers will probably be the first to offer
higher efficiencies in systems under       mize heat problems, and radically           mass produced electrics for the gener-
144 volts, which include most conver-      revised architecture that may give us       al public, with domestic manufactur-
sions. While fewer IGBTs are needed,       batteries shaped like thermos bottles.      ers limiting their focus to fleets.
each one is much more expensive than         While the advanced lead acid batter-        The performance of today’s technol-
the MOSFETs. IGBT controllers tend         ies can’t approach the energy-weight        ogy is adequate for most people’s dri-
to be bulkier and noisier, since they      goals of the exotic batteries, they may     ving needs. However, as new technol-
operate best at lower frequencies than     provide the same energy as traditional      ogy becomes available, today’s cars
MOSFETs. They also require more            lead acid batteries at half the weight—     can be upgraded. Every time the bat-
cooling.                                   and about the same cost.                    tery pack is replaced, it will have
  It’s too early to call the results on      Like the motor and controller manu-       more energy per pound and a longer
the MOSFET/IGBT debate, although           facturers, battery manufacturers are        lifespan than the pack it replaces.
it may evolve into parallel tracks like    looking at how their product interacts        The electric car is the only car that
the AC/DC debate. At this time, the        with the whole system, especially the       runs better the longer you own it.
MOSFET technology is the more              charger. In addition to developing
proven and established system.             lighter batteries that last longer, they    Resources
                                           are developing batteries that can             For a list of businesses supplying
Batteries                                  accept a charge faster, and the charg-      conversion kits and components, con-
                                           ers to match.                               version services, books and videos,
  Everyone wants to know, “When              Battery charging time is limited by
will they come up with a better bat-                                                   and turnkey cars, contact:
                                           heat. Fast charging produces heat
tery?” Like motors and controllers,        inside the battery, which shortens the       Electric Vehicle Industry Assoc.
the battery debate divides into parallel   battery’s life. Gassing is caused by         P.O. Box 59
tracks.                                    built-up heat literally boiling the elec-    Maynard, MA 01754
                                           trolyte.                                     (508) 897-6740


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November/December 1994 Backwoods Home Magazine


  For the location of an electric car
club near you, contact:
 The Electric Auto Association
 (800) 537-2882

  For information on tax incentives
and legislation relating to electric cars,
contact:
 Goldschein & Gomez
 Alternative Energy Consultants
 221 “G” Street, Suite 207
 Davis, CA 95616
 (916) 753-8057 ∆




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