Abstract: A power monitor for an electrically powered device provides audible and/or visual alarms in the event of a power failure in a particular branch circuit. A timer records the duration of the power outage and reports the result on a built-in display. Optional performance sensors may monitor and report the condition of the electrically powered device being monitored. A representative embodiment is a monitor for a refrigerator/freezer. A temperature sensor in each of the two compartments triggers an alarm if pre-set temperature limits are exceeded. The power monitor comprises an internal, rechargeable battery which powers the device during a power outage.