One of the biggest batteries in Australia's main grid reaches full output, as its owner's owner seeks buyer for its entire portfolio.

Grid scale and residential Battery storage in Australia has increased so much the energy regulator will supply free electricity next month.

"Evil, poisonous and treacherous" was the description from one Queenslander about the central NSW battery project. It is now seeking federal approval.

One of the biggest batteries in Australia's main grid reaches full output, as its owner's owner seeks buyer for its entire portfolio.