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.
Polarity - In electricity, the condition of being positive or negative.
Crest factor (Fc) - Ratio between the peak current value to the rms current value.
Absorption - The taking up or retention of one material by another by chemical or molecular action.
Spiral Wound - An electrode structure of high surface area created by winding the electrodes and separator into a spiral-wound, jelly-roll configuration.
Capacity Retention (or Charge Retention) - The fraction of the full capacity available from a battery under specified conditions of discharge after it has been stored for a period of time.
Harmonic Sinusoidal - Term of the Fourier series expansion of a periodic function. The harmonic (or harmonic component) of the nth order is characterized by - Yn is the rms value of the given harmonic component, w is the angular frequency of the fundamental, related to frequency by - w = 2_f; phin is the phase angle of the given harmonic component at t = 0.