Dual battery

[Shakey]

Hi

I was wondering if I could have some advice, I'm looking to add blue sea add a battery.

I understand the generic wiring diagram, but a bit confused on how to split the accessories from starting battery, as I have a mercruiser 4.3 engine with a 10 pin engine harness which powers the fuse block for gauges, lights, fish finder and stereo etc.

All I want is one battery for starting and gauges and the other battery for stereo etc.

Thanks for reading,

[shrew]

Do you have a single pole battery isolation (On/OFF) switch now?

[donald]

Use the battery selector switch to do the isolation of the batteries.
Switch from one battery to the other as needed that way you will have battery in reserve to start engine if needed.
Don

[mmwjr]

You didn't say what size boat you have but it sounds like it has a single 4.3 so I'm assuming this is a basic runabout 18 - 22' long. I would do as Don suggested, use one battery while running and the other while at anchor this way the start/run battery is always isolated. A simple off - Batt1 - Both - Batt2 switch will accomplish this.

[lakelifebc]

Depends on the boat. My 1800SR3 has separate +'ve cables for Starter, Tilt/Trim motor & House (dash, stereo, gauges, etc) all currently connected to a single battery (with the house +'ve going through the battery switch).

When I do the Add-A Battery this Spring, Starter and Tilt/Trim +'ve will go to 1 battery (the "Starter" battery) and the house +'ve will go to the "House" battery; both wired through the new switch and ACR isolator as per the wiring diagram.

Or do similar through a simple Off-1-Both-2 switch as a few others have said.

[Shakey]

Sorry for the late reply been hectic,
Yes I have a single battery switch on/off

[donald]

Change the battery switch to a 1-2-both-off and add the other battery, and you will be all set.
Just remember that the cables need to the same size as the battery cables already there.
Don