Batteries are new. Even installed new alternators on both engines. Garmin checked out unit and says it is fine. We can run with the unit on and sometimes it will stay on for 20 minutes before it completely shuts off. Sometimes it even locks up. Power unit is hooked directly to battery. We have the Garmin transducer, fuel sensors and GMR-24 connected through the NMEA 2000 Starter Kit. Thanking you for your input Rick |