Well YES, only using either battery 1 or 2 position and the OFF position.
But NOTE, they are 2 different animals of the term 'dual' ...
Dual Battery Switch - This switch connects 2 separate batteries, where it has 4 switch positions - Off - 1 - Both - and 2. On my 2-battery boats, I'd run out on #1 and run back in on #2. Or run #1 on odd days of the calendar and #2 on even days. You can do it anyway you want ... but the intent here is to use both batteries to keep them fresh/charged and keep the one charging when running off it.
Be aware that in the Both position, they will equalize if left in that position for a while. If one battery was 95% and the other was 65% ... after a period of time, and if the engine is off, they will both settle @ 80%. Note that with some OBs that need a minimum voltage to fire the electronics and not just to 'crank' the flywheel, that there might not be enough juice/power to start the motor.
Typically the 'Both' position is reserved for Emergency starting only. Also note you really can't run on Both of the 2 batteries are different types, as with different types, you could cook one of the batteries and then the other might not charge.
Dual-Purpose Battery - It's really a blend of the plate design within the battery, part of a cranking type design, think power (max amps) and yet still allows a deep cycle pull down or deep discharge, think duration (hours). Consider of it like a cranking battery can give give a TON of amps, but not for a long time, whereas a deep cycle battery can do a slow amp draw for days. The dual purpose tries to give the User a little of both in one battery, like a combination. They are hard to find nowadays for some reason, but I always had good luck with them.
Well YES, only using either battery 1 or 2 position and the OFF position.
But NOTE, they are 2 different animals of the term 'dual' ...
Dual Battery Switch - This switch connects 2 separate batteries, where it has 4 switch positions - Off - 1 - Both - and 2. On my 2-battery boats, I'd run out on #1 and run back in on #2. Or run #1 on odd days of the calendar and #2 on even days. You can do it anyway you want ... but the intent here is to use both batteries to keep them fresh/charged and keep the one charging when running off it.
Be aware that in the Both position, they will
equalize if left in that position for a while. If one battery was 95% and the other was 65% ... after a period of time, and if the engine is off, they will both settle @ 80%. Note that with some OBs that need a minimum voltage to fire the electronics and not just to 'crank' the flywheel, that there might not be enough juice/power to start the motor.
Typically the 'Both' position is reserved for
Emergency starting only. Also note you really can't run on Both of the 2 batteries are different types, as with different types, you could cook one of the batteries and then the other might not charge.
Dual-Purpose Battery - It's really a blend of the plate design within the battery, part of a cranking type design, think power (max amps) and yet still allows a deep cycle pull down or deep discharge, think duration (hours). Consider of it like a cranking battery can give give a TON of amps, but not for a long time, whereas a deep cycle battery can do a slow amp draw for days. The dual purpose tries to give the User a little of both in one battery, like a combination. They are hard to find nowadays for some reason, but I always had good luck with them.