Trickle Charge - A charge at a low rate, balancing losses through local action and/or periodic discharge, to maintain a cell or battery in a fully charged condition.
Capacity - The total number of ampere-hours or watt-hours that can be withdrawn from a fully charged cell or battery under specified conditions of discharge.
Shelf Life - The duration of storage under specified conditions at the end of which the battery still retains the ability to give a specified performance.
Top-Up Charge - A low rate charge following the main charge, designed to ensure maximum capacity.
MTTR (Mean Time To Repair) - Mathematical calculation (or statistical average if available) of the time required to repair a device.
Frequency Variation - A change in frequency of more than 3 Hz.
Bypass (manual) - Manually-operated switch used to supply the load via direct connection to utility power during servicing of the UPS system.
