Batteries

[mainexile]

My '77 Grady White with a Mercruiser 470 4-cylinder has two starting batteries connected in parallel. The batteries both seem to have at least one dead cell each since they are not holding a charge and there is no external draw. Two questions: 1) Is it common for an engine of this size to need the amperage from two starting batteries? (I've heard that boats capable of going offshore frequently are configure with two starting batteries - one primary and the other backup), and 2) could I separate them with a one/other/both type switch?

 

[dingbat]

Re: Batteries

I have 2 - grp. 27 deep cell batteries on my Grady. One is used for starting the motor and the other for running the house load.

They're hooked up to a selector switch so I can use either battery to start the motor if need be.

FWIW: I'm running a 6 cylinder 200 hp outboard and have never had to combine the batteries to start the motor.

 

[mainexile]

Re: Batteries

dingbat,

Thanks for the reply. Right now the two batteries in parallel are connected to a large on/off rotary switch, so I don't have the option of selecting one or the other. And my boat doesn't have a separate house circuit.