IR Drop - A voltage drop associated with the electrical resistance (R) of a battery or current flow (I). The voltage drop is the product of the current (in amperes) and the resistance (in ohms).
Temperature Cutoff (TCO) - A protective or safety device (e.g., thermostat, PTC, etc.) which senses temperature (e.g., in a battery) and opens or cuts off the electrical circuit if the specified temperature is exceeded, thus preventing a further rise in temperature due to the charge or discharge of a battery.
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.
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.
Electrical Line Noise - Radio Frequency Interference (RFI) and Electromagnetic Interference (EMI) are unwanted electrical signals that produce undesirable effects in sensitive electronic equipment.
Thermistor - A temperature sensitive resistor, usually made from specially processed oxides.
Polarization - The lowering of the potential of a cell or electrode from its equilibrium value caused by the passage of an electric current.
