General GNX News, page-1350

Lithium batteries are known for being able to producer higher currents than what they are rated for. In this case it is only 200%. Some can produce up to 25 times their rating. Because the Power has been increased, the time will decrease as it is inversely proportional. The battery could also be used as 50MW for 6 hours in the other extreme. Watts x hours = Battery capacity.
600MW for 0.5 hours may have been less confusing without taking efficiencies into account.