Tolerance in % - Limit for allowable variations for a given quantity, expressed as a percent of the rated value.
Forced Discharge - Discharging a cell in a battery, by the other cells or an external power source, below zero volts into voltage reversal.
Earthing system TT - Earthing system in which the neutral and the exposed conductive parts are directly earthed. The installation must be de-energized immediately in the event of an insulation fault.
COS phil - A measure of the phase shift between the fundamental current wave and the fundamental voltage wave observed at the terminals of a non-linear load.
Critical Load - Devices and equipment whose failure to operate satisfactorily jeopardizes the health or safety or personnel and/or results in loss of function, financial loss, or damage to property deemed critical by the user.
Self-Discharge - The loss of useful capacity of a battery on storage due to internal chemical action (local action).
Discharge Rate - The rate, usually expressed in amperes, at which electrical current is taken from the battery.