Wall-less Design - A battery design where the structural support for the cells is formed by an open plastic framework.
RMS Voltage - The range of usable voltage + or - 170 VAC.
COS phi - A measure of the phase shift between the current wave and the voltage wave observed at the terminals of a load supplied with AC power at a given frequency.
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.
Safety Vent - A venting mechanism designed into a cell which activates under specific conditions of abuse to relieve internal pressure.
Rectifier/charger - UPS component that draws on the mains the power required to supply the inverter and to float charge or recharge the battery. The alternating input current is rectified and then distributed to the inverter and the battery.
IEC (International Electrotechnical Commission) - Advisory organization that draws up international standards in the electrotechnical field.