Capacitors store voltage and are used in circuits as temporary batteries. Capacitors are charged by DC current (AC current passes through a capacitor) and that stored charge can later be dissipated into the circuit as needed. Capacitors are often used to maintain power within a system when it is disconnected from its primary power source or to smooth out or filter voltage within a circuit.

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

A photovoltaic cell (also known as a solar cell) converts energy from the sun into electrical energy.

Direct current flows in only one direction in a circuit, from the negative terminal of the voltage source to the positive. A common source of direct current (DC) is a battery.

In contrast to the constant one-way flow of direct current, alternating current changes direction many times each second. Electricity is delivered from power stations to customers as AC because it provides a more efficient way to transport electricity over long distances.