Current loop (20 mA) - Transmission system used on certain devices and offering better performance than the RS232C. It provides a high degree of immunity to interference and is easy to implement, but has not been standardized.
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.
Gassing - The evolution of gas from one or more of the electrodes in a cell. Gassing commonly results from local action (self-discharge) or from the electrolysis of water in the electrolyte during charging.
Inverter (off-line or stand-by) - UPS configuration in which the inverter is parallel-mounted to the load supply line and backs up the mains. This configuration offers a substantial cost reduction but is applicable only to low outputs, under 3 kVA, because it results in an interruption lasting up to 10 ms during transfer and does not filter inrush currents.
Blackout - A zero voltage condition lasting for more than two cycles. Same as a power failure
Forced Discharge - Discharging a cell in a battery, by the other cells or an external power source, below zero volts into voltage reversal.
Hourly Rate (also see C-Rate) - A discharge rate, in amperes, of a battery which will deliver the specified hours of service to a given cutoff voltage.