You had to watch the voltage and play with a rheostat
What’s better for electric car owners, public charging stations or home chargers? A century ago, the electric vehicle industry was adding public stations in big cities like New York and London, but also encouraging vehicle buyers to charge at home.
The tone of these campaigns was encouraging — “It requires no special electric or mechanical knowledge, and practically no attention or physical effort. When once installed, the charging apparatus may be operated by any member of the household after a few moments of instruction.”
Nothing motivates more than economics, and the sellers played on not only the extra expense of garage charging but also ‘range anxiety’.
“Aside from the garage charges, and the indifferent care that is often given to a car in a public garage, there is always a considerable loss due to the trip from the garage to the residence of the owner, and then back to the garage.”
How much driving range did owners lose by charging at a garage? “The great majority of car owners live two or three miles from the source of current. This means that from four to six per cent of the charge is expended uselessly; in hilly country this may be even higher.”
Although the sellers claimed charging a car at home was as simple as “filling a tank with water”, in practice it was more complicated. As the charge on a battery increased, the resistance of the charger had to be manually decreased using a lever on its rheostat.
These rheostats wasted a lot of energy as heat: “As an example of the extent of the rheostat loss, we will assume that the battery voltage is 80 and the line voltage 110, giving a difference of 30 volts. With a charging current of 40 amperes, there will be 30 times 40, or 1,200 watts, dissipated per hour (1.2 kilowatt-hours).” That’s enough current to make a Delhi apartment’s living room cosy in winter.
You really had to be a hands-on owner to charge your electric car those days: “adjust the lever of the rheostat until the needle of the ammeter on the control board or car reads an amount specified by the builder of the car, a process that is as simple as turning on a hydrant.”
You had plenty of time to get some chores done as the battery charged, and then, you came back and made another adjustment, and so on. “When the charge is completed he opens the line switch and removes the charging plug that connects the car with the lighting circuit. That is all.”
As easy as that.