MTTR (Mean Time To Repair) - Mathematical calculation (or statistical average if available) of the time required to repair a device.
Power source (alternate) - Backup source used in the event of a mains failure. The connection time and the duration of the source depend on the type of source used. (back)
Battery cells - The interconnected battery elements that supply electrical power created by electrolytic reaction.
Fuse - Device used for cutting off an electrical current in the event of an abusive condition.
Gassing - The evolution of gas from one or more of the electrodes in a cell. Gassing commonly results from local action (self-discharge) or from the electrolysis of water in the electrolyte during charging.
Output (rated) - Apparent power Pn that the UPS can deliver under given load conditions (power factor = 0.8).
IR Drop - A voltage drop associated with the electrical resistance (R) of a battery or current flow (I). The voltage drop is the product of the current (in amperes) and the resistance (in ohms).