| 摘要 |
A battery condition monitoring system for an emergency lighting system includes measuring means (110) for coupling to a battery (19) and operable to obtain an indication of the impedance of the battery. A reference impedance value storage means (114) which stores a reference impedance value of the battery. Monitoring means (112) is provided which is configured to periodically operate the measuring means to obtain an indication of the battery impedance, to compare this to the reference impedance value, and to estimate the battery condition in dependence thereon. The reference impedance value may be an indication of the impedance of the battery during an initial usage phase of the battery. The system can predict when battery capacity will become insufficient and alert the user to the need for battery replacement. |
