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 dioxide 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.