The 100-megawatt battery, built by Tesla, was officially activated on Friday. It had in fact provided some power since Thursday due to demand caused by local hot weather.
South Australia has been crippled by electricity problems in recent times.
Tesla build the battery within 100 days.
The battery would prevent a repeat of a notorious incident last year where the entire state lost power
It was described as three times more powerful than the world's next biggest battery.
