BENETEAU 40 Owner's Manual page 20

BATTERY SWITCH OPERATION
Never turn the negative battery switch off while engine is running.
Never turn all positive switches off while engine is running.
Battery 1 is the engine / start battery
Battery 2 is the service / house battery
Negative battery switch controls ground {DC12V negative} for all batteries.
WARNING: Do not turn both positive battery switches off while engine is running
Everything is OFF, no 12V DC power Everything is ON, 12VDC power available
( when leaving the boat unattended) to start engine and/or run equipment
Configuration to start engine, while
Engine is off , Run equipment from house only
house/service is off or down
( like at anchorage)
B40 Owner's Manual Page 20 of 28
June. 1, 2007
rev 00