Abstract: A live circuit battery tester allows for determining the condition of batteries under load without disconnecting the batteries and a battery charger from the load or in any way disrupting system operation during the test. Battery testing is prevented when the batteries are being used in an emergency or if they are recharging from a recent discharge. The battery tester is under microcomputer control and incorporates automatic-self diagnostics and provides a visual indication if the batteries are good or if a specific problem is detected such as if the batteries are missing, have open cells, are sulfated or are in imminent danger of failure. The battery tester determines if the charger is operating properly and tests for an open cell, bad battery connection, sulfated battery, and a weak battery and provides a visual indication of any of these problems as well as an indication of a properly operating battery.

Abstract: A monitoring annunciator apparatus for monitoring the status of field contact points, which apparatus cooperates with one or more contact points utilizing a single signal wire for each monitored point and a ground wire common to all monitored points, so as to provide separate audible and visual indication, or alternative actuation of a response, upon the occurrence of a change in status of each monitored field contact point and indication of the occurrence of change in the integrity of each wire pair.