Battery power for Ford pickups
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by Steve Sturgess • Ford becomes the first major US manufacturer to market an electric commercial vehicle. The battery-powered Ranger pickup starts life on the same production line as the petrol-engined base model but leaves the line with no engine, transmission, driveshaft. cooling system or fuel tank.
In this state it is shipped to engineering specialist TDM, where it is fitted with a threephase 312V electric motor rated at 100hp (75kW) and a singlespeed reduction gearbox which takes drive to the conventional rear drive axle. A pulse-width modulated controller fits above the motor in the Ranger's engine compartment, with space left over for a cooling system that circulates oil through the main drive motor and electronic control box.
TDM also fits 26 batteries beneath the floor at the front of the pickup bed. They give a range of 80km, depite the demands of the Ranger's heating, air-conditioning and power steering systems. Top speed is governed to 112km/h (70 mph) but the weight of batteries (900kg including crash-proof boxes and mountings) reduces ay load capacity to 450kg.
A separate motor drives an evacuation pump to provide brake boost and to acuate the heater flap while a battery under the bonnet caters for conventional systems such as lighting, instrumentation, blower fan, and windscreen wipers.
The electric Ranger's performance is comparable with that of the petrol model. The torque characteristics of the electric motor, which gives peak torque at stall, makes the truck feel positively sporty off the line, despite its 2,360kg kerb weight.
Regenerative braking puts some energy back into the batteries during a stop. While coasting some regenerative braking is applied to give the electric truck a similar feel to a petrol-powered unit: using the foot brake brings in more electrical retardatitm. Regeneration only gives a marginal increase in range. but adds omsiderahly to brake life which would otherwise be excessive because of the high kerb weight.
Like all lead/acid-battery electric vehicles. the Ranger suffers from the battery's relatively short life of up to two years. Replacements could cost more than £3,000, but set against this are low running costs. While a petrol Ranger might incur a fuel bill of around £38 a month, the electric model could be charged for about half the price. Maintenance costs should also be much lower, with only one moving part in the main piwer
Ford sees the TDM/Ford Ranger as an interim step in the development of the electric CV. The first step was the Ecostar demonstration program using Escort-based vans with sodium/sulphur battery technology. That program involved 21 fleets and 105 vehicles; some of what was learned will appear in the Ranger electric program which is due to start in 1998 with a factory-produced electric model.
The factory model will incorportate a nickel/metal hydride (NliMH) battery pack to increase cruising range with battery life of up to eight years.
Ranger EVs go into production this autumn; CM has driven a prototype.
Starting up is exactly like starting a conventional petrol unit, even to rotating the key to a start position. This brings on the controller and the cooling system and brake pumps: a small green icon glows in the right-hand dash gauge to indicate the truck's readiness.
Other gauges show battery charge and tell the driver if the accelerator is being used effi
ciently to maximize battery power—filling the same role as the shaded green section on a tachograph.
These are the only obvious differences from the driver's seat. The transmission selector looks exactly like an automatic's, but there is no bump when engaging Drive. Releasing the parking brake causes the EV to creep forward, just like a conventional automatic.
Acceleration is accompanied by a slight increase in noise— and the performance feels a lot stronger than that of a conventional petrol Ranger. In most cases the truck feels no different from an automatic transmission pickup, except that it steps off the line very smartly and is exceptionally smooth and quiet.
The regenerative braking was unobtrusive and the ride is exactly the same as a standard Ranger—with a tonne of payload in the back.