Thevenin generator - For a given load, it is possible to consider the power supply as a voltage generator, referred to as a Thevenin generator, made up of a perfect voltage Uo generator, in series with an internal impedance Zs - n Uo is the voltage measured across the load terminals, given that the load is to be disconnected (load terminals forming an open circuit), n Zs is the equivalent impedance as seen from the load terminals (again considered an open circuit), obtained by short-circuiting the upstream voltage generator(s).
Tolerance in % - Limit for allowable variations for a given quantity, expressed as a percent of the rated value.
Rated Capacity - The number of ampere-hours a battery can deliver under specific conditions (e.g., rate of discharge, end voltage, temperature); usually specified by the battery manufacturer.
Battery or Pack - Two or more electrochemical cells electrically interconnected in an appropriate series/parallel arrangement to provide the required operating voltage and current levels. Under common usage, the term "battery" is often also applied to a single cell.
Top-Up Charge - A low rate charge following the main charge, designed to ensure maximum capacity.
Separator - An ionic permeable electronically nonconductive spacer or material which prevents electronic contact between electrodes of opposite polarity in the same cell.
Frequency Variation - A change in frequency of more than 3 Hz.
