How would you connect 8 [15V 25A] batteries to achieve a combined power output of 15V 200A?

Connecting the 8 batteries in series multiplies their voltage while keeping their current the same yielding a 120V 25A configuration. Connecting the 8 batteries in parallel multiplies their current while keeping their voltage the same yielding a 15V 200A configuration. Using a series-parallel connection, 4 batteries can be connected in series and 4 can be connected in parallel resulting in a 60V 100A configuration.