Inspect the physical condition of batteries and battery connectors, if readily accessible. Check operation of battery. power-loss alarms, if so equipped. operated rate the oximeter on battery power for several minutes to check that the battery is charged and can hold a charge.( The inspection so can be carried out on battery power to help confirm adequate battery capacity.) Check battery condition by activating the battery test function or measuring the output voltage. Check the condition of the battery charger and, to the confirm that it does, in fact. extent possible, charge the battery. Be sure that the battery is recharged or charging when the inspection is complete. When it is necessary to replace a battery, label it with the date.