Output (rated) - Apparent power Pn that the UPS can deliver under given load conditions (power factor = 0.8).
Current Collector - An inert structure of high electrical conductivity used to conduct current from or to an electrode during discharge or charge.
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.
Percent load - Ratio between the power Pu drawn by the load and the rated output Pn of a UPS system (Pu/Pn). Sometimes referred to as the load factor.
Open-Circuit Voltage (OCV) - The difference in potential between the terminals of a cell when the circuit is open (no-load condition).
Discharge - The conversion of the chemical energy of a battery into electrical energy, and the withdrawal of the electrical energy into a load.
Backup time - Time during which the UPS can supply the rated load with nominal-quality power while the mains are down. This time depends on the battery and the efficiency of the UPS. Typical backup ranges from five minutes to several hours.