What causes my batteries to alarm on my mercury 150 efi two stroke?

The alarm on your Mercury 150 EFI two-stroke engine typically indicates a battery issue, such as low voltage or a failing battery. It may also signal problems with the charging system, like a malfunctioning alternator or rectifier. Additionally, ensure that all connections are clean and secure, as corroded or loose connections can lead to alarm triggers. Regularly checking the battery's health and the charging system can help prevent these alarms.