At the 1909 opening, 35 miles (56 kilometres) of track had been completed with electricity supplied by the Electric Lighting and Supply Co. The electric tram system ran on 600 Volts DC supplied at first from two converter stations, No.1 converter station on East Terrace with 2,500 kW of AC to DC capacity and No.2 station at Thebarton with a capacity of 900 kW. To cope with variable loads on the system, very large storage lead–acid batteries were installed, the initial one at East Terrace comprising 293 cells and a 50 ton tank of sulphuric acid.