battery/alternator question in my SeaRay 290 ´96

[ConradDK]

Hey

i have bought a "new" boat. Its a SeaRay 290 Sundancer build in ´96
it has 2 x Mercruiser 4,3 MPI (freshwater cooled - 2017)

my question goes on how alternater do charge on batteries when there are 2 of then?
do they normaly charge the same battery?

i have 3 batteries. i beleave 1 for start and 2 for anything else..(parallel)
i have 2 switches abord. 1 with ON/OFF and 1 with 1, 2, Both and OFF.

does anyone know how things normaly work? - i know things could have changed many times during its lifespan.

kind regards
Lars
Denmark

 

[atrick]

One with only one battery charges only that battery, the other motor with 2 batteries will charge the one that the switch is on. When I'm running I leave that switch on both so both batteries get charged on that side then when I anchor turn switch to 1 or 2 so only one battery discharges while anchored which leaves you with a full charged battery to start the motor with. That's how its supposed to work if someone didn't change something.

 

[ConradDK]

One with only one battery charges only that battery, the other motor with 2 batteries will charge the one that the switch is on. When I'm running I leave that switch on both so both batteries get charged on that side then when I anchor turn switch to 1 or 2 so only one battery discharges while anchored which leaves you with a full charged battery to start the motor with. That's how its supposed to work if someone didn't change something.

Thanks..