dual battery switch

[myz3]

Recent purchase of 2016 Z3. Equipped with dual battery. Switch has three positions, Off and two on positions. Does anyone know what the positions run. Is position one the deep cycle battery (for stereo use) and position 2 the main cranking battery?
Thanks

[chpthril]

"ON" is on for the the boat is in use, "OFF" is off for when the boat is stored and "COMBINE" (the 4 oclock position) combines the two banks for en emergency crank. The boat has an ACR, Auto Combining Relay, that allows both banks to receive a charge from the alternator when the engine is running, but keeps the two banks isolated when the engine is off.

[myz3]

Thanks for clarification!!

[Bakes5]

Ok...I guess I've been doing this wrong for a while. No issues ever though. So, why wouldn't I want to be in combine while running and on while in the cove? Just wondering.

[Germaine Marine]

You can be in combine if you want, however On will accomplish the same thing charging wise as combine once the motor is running and you wont need to play with the switch every time...... thats the point of the switch and Auto Isolator.

[TigeFamily]

Also....in combine, you run the risk of running your cranking battery low and not being able to start the boat if you run stereo system or other features for a good while, during the chilling faze.