Hertz - The standard unit of frequency. A frequency of one complete cycle per second is a frequency of one hertz.
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.
Earthing system IT - Earthing system in which the neutral is isolated from the earth or connected to the earth via a high impedance and the various exposed conductive parts are connected to the earth via individual earthing circuits. An alarm must signal the appearance of a first insulation fault. The installation must be de-energized immediately in the event of a second insulation fault.
Hourly Rate (also see C-Rate) - A discharge rate, in amperes, of a battery which will deliver the specified hours of service to a given cutoff voltage.
Intermittent Test - A test during which a battery is subjected to alternate periods of discharge and rest according to a specified discharge regime.
Voltage Delay - Time delay for a battery to deliver the required operating voltage after it is placed under load.
Memory Effect - A phenomenon in which a cell or battery operated in successive cycles to the same, but less than full, depth of discharge temporarily loses the rest of its capacity at normal voltage levels.