Inverter (on-line) - UPS configuration in which the inverter is in series mounted between the mains and the load. All power drawn by the load passes via the inverter. This is the only configuration used for high outputs.
Depth of Discharge - The ratio of the quantity of electricity (usually in ampere-hours) removed from a battery to its rated capacity.
Capacity Retention (or Charge Retention) - The fraction of the full capacity available from a battery under specified conditions of discharge after it has been stored for a period of time.
MTTR (Mean Time To Repair) - Mathematical calculation (or statistical average if available) of the time required to repair a device.
Open-Circuit Voltage (OCV) - The difference in potential between the terminals of a cell when the circuit is open (no-load condition).
C-Rate (also see Hourly Rate) - Discharge or charge current, in amperes, expressed in multiples of the rated capacity. For example, C/10 discharge current for a battery rated at 1.5 Ah is:
Reversal - The changing of the normal polarity of a battery due to overdischarge.