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Tech Tip – Low Cranking Voltage Alarm

According to Cummins Power Generation, “Weak or undercharged starting batteries are the most common cause of standby generator system failures.”1 Because all lead-acid starting batteries fail over time, advance warning of a weakening battery can substantially reduce the risk of genset failures.

The most effective warning of a weakening battery is a modern low cranking voltage alarm. An effective low cranking voltage alarm examines the entire cranking cycle, and issues an alarm if battery voltage drops below critical threshold values. Because batteries are frequently able to start gensets when in a weakened, but not completely failed condition, the low cranking voltage alarm enables advance warning of a weakening battery. Prompt response to a low crank voltage alarm alarm thus enables pro-active replacement of the weakening batteries – before the next start attempt when the weakened battery might fail to start the genset at all.

MicroGenius 2 Low Cranking Voltage Alarm

For new applications, SENS’ MicroGenius® 2 battery charger includes a sophisticated low cranking voltage alarm as standard equipment. The charger’s low cranking voltage alarm captures all crank events, measures voltages and issues an alarm if any voltages drop below the critical values in EGSA reference 100B. Alarms are available visually, via J-1939 and on the optional Form C alarm relays.

Low Cranking Alarm Graph

Example of a cranking event stored in the MicroGenius 2 charger. Graphical display of crank events and exact values are available from the charger via the optional SENS USB cable using free downloadable software from SENS.

Battery Informer For Legacy Systems

For legacy applications where a charger is already installed, SENS offers the highly sophisticated BatteryInformer® genset battery monitor. Suited to the millions of gensets already installed, BatteryInformer provides a new level of cost effective battery management in which the battery’s true end of life can be detected. The BatteryInformer displays an estimate of the battery’s remaining life, along with alarm LED and remote contact alarm indications.

Battery Informer Table

Table of alarms and contact closure actions in the BatteryInformer® genset battery monitor

The low cranking voltage alarm is standard in the MicroGenius 2 charger. The BatteryInformer is very low in cost, making it accessible to nearly every genset owner and service organization.

Contact a SENS representative today for more information on how low cranking voltage alarm can reduce your risk of downtime.
1Iverson, James R., Digital Control Technology Enhances Power System Reliability and Performance, Cummins Power Generation publication PT-7002, Minneapolis MN: Cummins Power Generation