Reactance (subtransient Uscx %, for generator) - Relative measurement (%) of the internal impedance of an AC generator during harmonic phenomena. This reactance, also called the longitudinal subtransient reactance of the generator, is sometimes identified as X"d. For most common generators, the value ranges between 15 and 20%. It can drop to 12% for optimized systems and to 6% for special devices.
Positive Temperature Coefficient (PTC) - A thermally reactive device which becomes highly resistive at a specific temperature or current.
Forced Discharge - Discharging a cell in a battery, by the other cells or an external power source, below zero volts into voltage reversal.
Alloy - A mixture of several other metals or a metal and a non-metal.
Power Surge - Voltage above 110% of rated RMS voltage for one or more cycles.
Coulomb - The amount of electricity transported by a current of one ampere flowing for one second.
Polarity - In electricity, the condition of being positive or negative.
