How are battery cells connected in series to increase voltage?

To increase voltage in a battery system, cells are connected in series by linking the negative terminal of one cell to the positive terminal of the next cell. This connection method allows the voltages of individual cells to add together.

In this particular configuration, you effectively create a single larger voltage source rather than simply stacking capacities. When the negative terminal of the first cell connects to the positive terminal of the next cell, the remaining terminals (positive of the first cell and negative of the second cell) can then be used as the output terminals.

This series arrangement is fundamental in batteries, where combining multiple cells of a lower voltage results in a higher overall voltage necessary for a variety of applications, from powering devices to starting engines. The other options do not correctly describe how series connections work; hence they would not result in the desired increase in total voltage.