Filter (phase-shift) - Filter used to reduce, if necessary, the overall distortion due to the current harmonics injected into the mains upstream of a UPS by its rectifier-charger. Filtering is superior to that of a traditional filter of the L or C type.
Service Life - The period of useful life of a battery before a predetermined end-point voltage is reached.
Electrolyte - The medium which provides the ion transport mechanism between the positive and negative electrodes of a cell.
RMS Voltage - The range of usable voltage + or - 170 VAC.
C-Rate (also see Hourly Rate) - Discharge or charge current, in amperes, expressed in multiples of the rated capacity. For example, C/10 discharge current for a battery rated at 1.5 Ah is:
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.
Charge - The conversion of electrical energy, provided in the form of electrical current from an external source, to restore the chemical energy in a cell or battery.