Starter or House Battery?

[rrobar]

Hi Gang,

I''m redesigning the electrical system for our 28 year old sailboat to have a separate house and starter battery.

Everything I''ve read states that the starter battery is connected to *only* the starter.

Question: which battery (house or starter) is typically used to power the engine instruments, fuel pump, etc.?

thanks in advance for your help!
randy

[jbanta]

Thinking about this I see no reason at all for to run insturments when the engine isn''t running. Ok all kidding aside. ALL engine funtions should be in the circuit with the starter battery. Most of these funtions will be handled by the alternator and therefore have very little impact on the battery. Your house circuits should be limited to the power requirements you want for better living in your cabin and safer living on deck...

[dpboatnut]

On my boat, my theory was to ensure that no bone headed mistake would ever allow me to accidentally discharge the starter battery. With that in mind, nothing but the starter has the ability to suck amps from the engine battery, and the only other wire touching it is the lead from the battery combiner for charging from the alternator or shorepower. If the starter battery does somehow let me down, it''s lead is lead through a switch that lets me start using the house bank. I can go sailing for weeks and never touch the battery switches, and not worry about whether I''ve accidentally let the starter battery discharge.

Whatever setup works to get you confident that you''ll at least get starter sounds when you press the go-home button, is the one to install.

Best,
-Chad