Energy Density - The ratio of the energy available from a battery to its volume (Wh/L) or weight (Wh/kg).
C-Rate (also see Hourly Rate) - Discharge or charge current, in amperes, expressed in multiples of the rated capacity. For example, C/10 discharge current for a battery rated at 1.5 Ah is:
Inverter (on-line) - UPS configuration in which the inverter is in series mounted between the mains and the load. All power drawn by the load passes via the inverter. This is the only configuration used for high outputs.
Protection index (IP) - Index indicating the capacity of an electrical device to resist environment conditions. It is made up of three digits (e.g. IP 205), each corresponding to a type of environmental risk. The higher the number, the greater the capacity to resist. First digit (0 to 6) - capacity to resist penetration by solid objects. Second digit (0 to 7) - capacity to resist penetration by liquids. Third digit (0, 1, 2, 3, 5, 7, 9) - mechanical strength.
Top-Up Charge - A low rate charge following the main charge, designed to ensure maximum capacity.
Filter (phase-shift) - Filter used to reduce, if necessary, the overall distortion due to the current harmonics injected into the mains upstream of a UPS by its rectifier-charger. Filtering is superior to that of a traditional filter of the L or C type.
Ambient Temperature - The average temperature of the surroundings.
