As their names indicate, a step-up transformer is used to step up or increase voltage and a step-down transformer is used to step down or decrease voltage. In a step-up transformer, the secondary voltage is higher than the primary voltage and it has more turns in the secondary winding than in the primary winding.

Connecting the 6 batteries in series multiplies their voltage while keeping their current the same yielding a 90V 25A configuration. Connecting the 6 batteries in parallel multiplies their current while keeping their voltage the same yieleding a 15V 150A configuration. Using a series-parallel connection, 3 batteries can be connected in series and 3 can be connected in parallel resulting in a 45V 75A configuration.

A series circuit has only one path for current to flow. In a series circuit, current (I) is the same throughout the circuit and is equal to the total voltage (V) applied to the circuit divided by the total resistance (R) of the loads in the circuit. The sum of the voltage drops across each resistor in the circuit will equal the total voltage applied to the circuit.

Connecting the 10 batteries in series multiplies their voltage while keeping their current the same yielding a 150V 5A configuration. Connecting the 10 batteries in parallel multiplies their current while keeping their voltage the same yielding a 15V 50A configuration. Using a series-parallel connection, 5 batteries can be connected in series and 5 can be connected in parallel resulting in a 75V 25A configuration.

Ohm's law specifies the relationship between voltage (V), current (I), and resistance (R) in an electrical circuit: V = IR.