An emergency power diagnosis system measures the exact value of impedance voltage (Vis) from an AC actual waveform (VSM) includes circuits and software operable to measure the effective resistance of battery internal impedance to determine the expected life of a battery string. The system is configured...http://www.google.de/patents/US7567085?utm_source=gb-gplus-sharePatent US7567085 - Diagnosis for expected life of emergency power apparatus
