70 Miles Non-stop on a Battery-electric
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BATTERY-ELECTRIC vehicles are known to.. give 'their best performance when the weather is warm and dry, but on the day when I tested the Brush 25-30-cwt. van conditions were far from ideal, and I was most surprised that a continuous run of over 70 miles should have been covered before the batteries showed sign of failing.
Having made a difficult journey to Loughborough through snow, '.1 was pleased to find that the model to be tested was fully enclosed and that it had twin rear wheels. The van was being loaded with a representative payload of pig-iron ingots when I arrived, so I took the opportunity of inspecting a chassis in the works before setting out on the test. Simplicity is the keynote of the design, and the numerous solenoids and resistances sometimes associated with battery-electrics are reduced to a minimum in favour of more " mechanical " details.
Simplicity of Maintenance For example, the pedal-operated parallel-series controller is in a drum form, located under the driver's seat. A mechanic, not necessarily an electrician, can remove the entire drum in a few minutes, service it on the bench and replace it with the same ease. Electrical connections are maintained at a minimum and may easily be followed through by the average service mechanic.
The main current is broken by a mechanically operated contactor, fitted with magnetic blow out, ensuring that the contacts last a A32 considerable time before replacement is necessary. Provision is made for the driver who is in the habit of applying the brake and accelerator pedals at the same time, thereby causing damage to the motor. As soon as the brake is applied, the controller drum is tripped to the " off " position and the accelerator is neutralized. To prevent the vehicle from being driven away while the charger is in circuit, the charger socket cover is fitted with an interlocking arrangement.
Both main frame members are of all-welded box section, dropped at the front to give easy access to the cab. Transverse members, formed to carry the battery, motor and controller, afford rigid bracing to the frame. The batteries are carried pannier-fashion in enclosed boxes between the axles, and are withdrawn and replaced through removable side valances.
Of one-piece banjo construction, the rear axle employs double
through the series range. This method prevents a shock load from being thrust on the batteries, but slightly reduces range, because longer periods are spent tinder power, with a correspondingly shonef period of free-wheeling between points.
Under these conditions, approximately 150 yds. of the distance between stops was spent with the motor in circuit and the remainder of the 70 yds. in free-wheeling and braking. From the current used over this course of eight stops in every mile, it was deduced that, under similar conditions, the vehicle would have a range of 49 miles, and that a net average speed of 12 m.p.h. could be maintained.
Inter-urban Delivery
I drove the van for the second test of four stops per mile and, finding that the maximum speed of 18 mph. could be achieved between points, took acceleration figures at the same time. It was found that from rest, 15 m.p.h. could be reached in 10 secs. and 18 m.p.h. in 18 secs.—a comparatively good performance for a battery-electric.
Having used the stop-watch for the acceleration tests, I was unable to check the average speed for this stopstart test, but the result would have been slightly better than that of the previous test, had the time been