This INTEGER is the highest input voltage (in millivolts) seen at the blade motherboard's power input during the interval captured by this archived history record. A spike well above the nominal ~12000 mV rail here can indicate a transient overvoltage event on the chassis power bus, which is exactly the kind of momentary excursion an average alone would hide. Seeing inputVoltageMax jump to 13200 mV for one recorded interval, even briefly, is the kind of anomaly worth cross-checking against chassis PSU logs.