- Cell Voltage is in Volts - V (Vc = Cell Voltage).
- Cell Capacity is in AmpHours or milli-AmpHours - Ah or mAh (Ahc = Cell AmpHours)
For example, if a higher voltage is desired, cells are assembled in series and if a higher current capacity is desired, cells are assembled in parallel.
- Series batteries have the negative (-) terminal of the 1st cell connected to the positive (+) terminal of the next cell in the string. The battery voltage is the cell voltage multiplied by the number of cells in the string, while the capacity remains the same.
- Parallel batteries have both (+) terminals and both (-) terminals of each cell connected together. The battery voltage equals the cell voltage, but the capacity is the cell capacity multiplied by the number of cells in parallel. Cells in parallel should be matched for best performance, while lithium primary cells in parallel must have blocking diodes for safety reasons and lithium-ion cells must be matched for safety reasons.
- Series-Parallel batteries have identical string sets of series cells assembled in parallel at the (+) and (-) terminal ends, but the interior cell connections are normally not connected to each other. The battery voltage equals the voltage of the strings and the capacity equals the cell capacity multiplied by the number of strings.
There are accepted industry abbreviations for these configurations. Examples:
- 1S1P = A single cell battery. V = Vc and Ah = Ahc
- 1S2P = A battery with 1 cell in series and 2 cells in parallel. V = Vc x 1 and Ah = Ahc x 2
- 2S1P = A battery with 2 cells in series and 1 cell in parallel. V = Vc x 2 and Ah = Ahc x 1.
- 2S2P = A battery with 2 cells in series and 2 cells in parallel. V = Vc x 2 and Ah = Ahc x 2.