Service Life - The period of useful life of a battery before a predetermined end-point voltage is reached.
Specific Energy - The ratio of the energy output of a cell or battery to its weight (Wh/kg). This term is used interchangeably with gravimetric energy density.
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.
Thermostat - A temperature sensitive switch.
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.
Closed-Circuit Voltage (CCV) - The potential or voltage of a battery when it is discharging or charging.
Brownout - A steady state RMS voltage under nominal by relatively constant percentage.
