Service Life - The period of useful life of a battery before a predetermined end-point voltage is reached.
Fourier theorem - Theorem stating that any non-sinusoidal periodic function (frequency f) may be represented as a sum of terms (series) made up of - n a sinusoidal term with frequency f, called the fundamental frequency, n sinusoidal terms with frequencies that are whole multiples of the fundamental frequency, (harmonics), n a possible DC component where n is a whole number. n = 1 corresponds to the fundamental, n > 1 to the harmonic of the nth order.
Hazardous Waste - Waste which is classified as "hazardous" (i.e., potentially harmful to the environment) by the government.
MTBF (Mean Time Between Failures) - Mathematical calculation of the duration of normal operation of a repairable device between failures. The product, expressed in hours, is an indication on the reliability of the device.
UPS (parallel without redundancy) - A UPS made up of several (n) parallel-connected UPS units with equal output ratings (P) and each equipped with its battery, for large loads. The total output is equal to the number of units multiplied by their individual output (n x P). In this configuration, no UPS unit is redundant.
Redundancy (standby) - UPS configuration in which one or several UPS units operate on stand-by, with no load or only a partial load, and can immediately back up a faulty UPS unit by no-break transfer of the load, carried out by a static switch.
Depth of Discharge - The ratio of the quantity of electricity (usually in ampere-hours) removed from a battery to its rated capacity.