I've had my Force for almost nine years now, and couldn't be more pleased. It is a perfect fit for my needs. (I live 5 miles from work and drive about 100 miles a week around our small town.) The Force is a normal-sized car that offers safety, performance, comfort, and passenger capacity which matches other cars on the road. I drive it year-round here in Oklahoma where it works quite well in an ice storm or in summer heat.
When I purchased the Force in 2000, the first hybrids were just being announced. But for a city runabout, the Force is a zero-emissions option that is vastly simpler in design. On top of that, I received generous state and federal tax credits for a pure-EV purchase instead of the tax deduction that hybrids get. As a result, my net outlay for this car that will probably outlast me was quite low.
Even though the car design seems simple, there is great genius in the implementation. The "heart" of the car is the Solectria controller. This clever inverter converts the fixed DC voltage from the batteries into the optimum voltage, current, and frequency for the AC motor to meet the driver's throttle setting. It delivers smooth, proportional control of both acceleration and deceleration over the entire speed range of 0 to 70 mph. This provides a very natural feel to the driver by incorporating regeneration into the throttle control. The conversion of the Metro to electric drive is truly professional, with custom harnesses, meters, and controls. The electronics are well-designed and well-packaged.
Another important item is the charger. This on-board unit works from 120V or 240V and has enough intelligence to keep the batteries at their optimum state of charge. It never overcharges the batteries so there is no problem with hydrogen gas or acid fumes. I drove 25,000 miles on the original gel batteries, replacing them when my range had reduced to about 20 miles.
Now that Iíve replaced the batteries, I can compute the cost of operation of the car. The Force needs very little maintenance compared to a gas or diesel vehicle. Including the cost of batteries as well as the cost of electricity to charge the car, my operating costs total 9 cents per mile. (This does not include the cost of tire replacement.)
I chose to buy the Force with sealed gel lead-acid batteries. This was the cheapest option but there were additional reasons for making this choice. The other battery options have their own drawbacks. Nickel-cadmium batteries and the NIMH batteries both put out considerable heat during charging and discharging, resulting in a lower overall efficiency than that of lead-acid packs. They also require heat-removal systems which add complexity and weight. With the lead-acid batteries, I just plug the car in whenever it's in the garage and don't have to be paranoid about whether I've cycled the batteries optimally. Solectria evaluated many varieties of battery before determining that the gelled sealed units from Sonnenschein are the best overall. Mine are labeled "Gel-Tech".
There are many small matters which contribute to both safety and to a polished design. For example, the brake light comes on whenever you are using significant regenerative braking. There is also a switch on the console to disable regeneration in cases where a slick road surface might make front-wheel deceleration hazardous.
Acceleration in the Force is rather like that of a commuter train. When starting out, flooring the accelerator pedal results in a smooth ramp of speed accompanied by a soft rising pitch from the inverter and gearbox. Although there is no gear-changing transmission, an integral gear reduction and differential couples the motor to the Metro front axles.
An electric car is quite a novelty in this part of the country. If it weren't for the "Electric" lettering on the car, nobody would recognize it as anything but an ordinary Metro. Many people are surprised that it's such a "big" car, because they expect an electric to be a tiny, odd-shaped vehicle for efficiency. People around here are accustomed to driving between towns that are 30 to 50 miles apart, so the idea of an in-town car is somewhat alien. The Force also does not have appeal to the pickup-and-horsetrailer folks who live out in the country.
Solectria provided in-person training for all
maintenance tasks involving the electric drive. This involves learning how to
diagnose problems and how to remove and replace the various components. There is
also a service manual which thoroughly covers the same information. The car is
incredibly simple and accessible compared to an ordinary vehicle. Faulty
components are returned to the factory for repair.
Gordon designed a terrific battery monitoring system for his Force that can be used in any electric vehicle. Its design and construction are detailed here.
|Gordon and his green 2000 Force|
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This page last updated 11/05/08