Mercury chief executive Fraser Whineray said the high voltage grid-connected battery storage had the potential to be a ''game-changer'' for Auckland.
''This could make a real difference to the way power is supplied to homes and businesses over the coming decades particularly as populations grow,'' he said.
Many New Zealand companies were looking at the opportunities from the development of battery technology.
''Mercury's strategic, R and D-focused project takes this to the next level, gaining scale experience in energy trading between battery and grid, and delivering competitive outcomes for our customers."
Mercury's general manager of hydro-wholesale, Phil Gibson, said the investment in the trial was small by the scale of Mercury's operations but would allow it to learn about the technology.
''This will last 10 to 20 years and we're watching the cost curves of batteries and seeing when the business case might be applicable.''
Lines company Vector is also trialling batteries in Auckland.