Battery cells - The interconnected battery elements that supply electrical power created by electrolytic reaction.
End Voltage (also see Cutoff Voltage) - The prescribed voltage at which the discharge (or charge, if end-of-charge voltage) of a battery may be considered complete.
Duty Cycle - The operating regime of a battery including factors such as charge and discharge rates, depth of discharge, cycle duration, and length of time in the standby mode.
MTTF (Mean Time To Failure) - Mathematical calculation of the duration of normal operation of a non-reparable device, i.e. for which a MTBF is not possible. The product, expressed in hours, is an indication on the reliability of the device.
UPS (Uninterruptible Power supply) - An electrical device providing an interface between the main power supply and sensitive loads (computer systems, instrumentation, etc.). The UPS supplies sinusoidal AC power free of disturbances and within strict amplitude and frequency tolerances. It is generally made up of a rectifier/charger and an inverter together with a battery for backup power in the event of a mains failure.
Load (linear) - Load for which voltage form and current form are similar. Voltage and current are related by Ohm's law U(t) = Z x I(t).
Power Surge - Voltage above 110% of rated RMS voltage for one or more cycles.