Fuse - Device used for cutting off an electrical current in the event of an abusive condition.
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.
End Voltage (also see Cutoff Voltage) - The prescribed voltage at which the discharge (or charge, if end-of-charge voltage) of a battery may be considered complete.
Midpoint Voltage - The voltage of a battery midway in the discharge between the start of the discharge and the end voltage.
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.
Bypass (manual) - Manually-operated switch used to supply the load via direct connection to utility power during servicing of the UPS system.
Voltage (float) - DC voltage applied to the battery to maintain its charge level. This voltage depends on the type of battery, the number of cells and the manufacturer's recommendations.
