| Word | Description |
| Parallel Circuit | A circuit in which the current has more than one path to follow. In this configuration, two batteries of equal rating are wired together positive (+) to positive (+) and negative (-) to negative (-). In parallel, the RC (Reserve Capacity) and CCA (Cold Cranking Amps) double while the voltage remains the same as the weakest individual battery. |
| Photovoltaic | Of, relating to or utilizing the generation of a voltage when radiant energy falls on the boundary between dissimilar substances, such as two different semiconductors. |
| Plate | A composite of a grid framework and the chemical active material. See Positive Plate and Negative Plate. |
| Polarity | The particular state of a battery terminal, either positive (+) or negative (-) |
| Polarization | The electrical potential reduction of electrodes, typically arising from prolonged or rapid discharge of the battery |
| Positive (+) | Normally refers to the positive (+) battery terminal, which is the point to which electrons in the external circuit flow during discharge. Sometimes the positive (+) terminal cap or cable is red, designating positive (+) |
| Positive (+) Plate | The positive (+) electrodes of a battery composed of lead peroxide on a grid. See also Active Material |
| Potential Difference | Voltage or electromotive force (EMF) |
| Power | The rate at which work is done. Power is measured in watts. P (Power) = E (Voltage) x I (Current) |
| Primary Battery | A cell or battery designed to deliver its rated capacity once and then be discarded; it is not designed to be recharged. Primary batteries include alkaline, heavy-duty and general-purpose batteries |