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.
Overcharge - The forcing of current through a cell after all the active material has been converted to the charged state, that is, continued charging after reaching 100 percent state-of-charge.
Current (float) - DC current that maintains the battery at nominal charge, corresponding the float voltage. This current compensates open circuit losses.
Electrode - The site, area or location at which electrochemical processes take place.
Cutoff Voltage (also see End Voltage) - The battery voltage at which the discharge is terminated. The cutoff voltage is specified by the battery manufacturer and is generally a function of discharge rate.
Spiral Wound - An electrode structure of high surface area created by winding the electrodes and separator into a spiral-wound, jelly-roll configuration.
Internal Impedance - The opposition exhibited by a circuit element (cell or battery) to the flow of an alternating current (a.c.) of a particular frequency as a result of resistance, induction and capacitance.