The 100-megawatt battery in South Australia is designed to provide security to the state's electricity grid.
It will store enough energy to power 30,000 homes for about an hour.
Tesla's chief executive Elon Musk had said the battery would be free if it was not installed within 100 days of signing a contract for the project.
It appears the company will meet the 1 December deadline for installation of the battery array, which will be connected to a wind farm run by French renewable energy company Neoen.
