Distortion (individual) - Ratio between the rms value of an nth order harmonic and the rms value of the fundamental.
Interference (high-frequency) - High-frequency parasitic current that is either conducted (electrostatic origin) or radiated (electromagnetic origin) by a device.
Constant Current Discharge - A battery discharge regime whereby the current drawn during the discharge remains constant.
Hourly Rate (also see C-Rate) - A discharge rate, in amperes, of a battery which will deliver the specified hours of service to a given cutoff voltage.
Current Drain - The current withdrawn from a battery during discharge.
UPS (single) - A UPS made up of one single UPS unit (rectifier/charger, inverter and bypass) and a battery.
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.