How can I tell which batt is the house batt?

[Still Shear Pleasure]

I have an 86 300Dancer. 3batts and a 2 batt switch. I know each engine has a starter batt, so how can I tell which is the house?

 

[tony1b2000]

Fool proof method:
1.) Turn on any house light. Just need one on.
2.) Remove the positive lead from each battery one at a time.
Suggestion: To reduce any arcing, shut off all the dc breakers EXCEPT the house light breaker.

 

[wyrman]

I just did this today so I could install a solar charger on the house batteries. I did exactly as Tony said, except I pulled the negative off.

 

[Still Shear Pleasure]

DUHH!!! I feel REAL silly at the moment. Thanks to you both.

 

[Still Shear Pleasure]

one last (i think). When at sea, no engines running, should batt switches be turned off, and would that effect the house batt. On my old 26 Bayliner (loved that boat), I could place the switch on batt #2 and listen to radio for hours. Starter batt would be fine.

 

[wyrman]

I personally don't ever turn my batteries off.

 

[Lazy Daze]

The reason that worked like that with your Bayliner is because it was a single engine. "Most" likely, one of your batteries is ONLY a starting battery for one of the engines. The other two would be connected in parralel (you can figure this out easily by looking at how they are connected) and act as both teh starting battery for the other engine and the house.

 

[Still Shear Pleasure]

Thanks Lazy. I just read in another forum (Chaparralboats.com/boat talk), one of the contributors said "There is no such thing as a 'House Battery' on a Sea Ray". Wyrman, on this string says he never turns his batteries off. OK, on the hook, engines off, radio, fridge, and cabin lights on. Battery switches 'on', 'off', 'both' ,ect??! what if any effect is there on the batteries?

 

[wyrman]

If I'm not mistaken, the batteries that run the house stuff,(fridges,etc) also start the port engine.
That's probably why someone said there's no house battery.
I'm not sure what "effect" you're asking about.
It doesn't hurt the batteries to turn them off if that's what you choose to do.
I camped for a week last summer, and my batteries were fine. I never turned them off.
I did run the generator to heat water, it also charged the batteries during that time.

 

[Bt Doctur]

You have twins, each engine should have a dedicated starting battery , each engine should have its own 1 B 2 switch to combine 2 batteries to emergency start an engine. The "house" should be a standalone battery with an isolator or blue-sea charging system from one motor .
This way you never worry about an engine starting

 

[Henry Boyd]

I just did this today so I could install a solar charger on the house batteries. I did exactly as Tony said, except I pulled the negative off.

Safety note for everyone: ALWAYS REMOVE NEGATIVE BATTERY CABLE FIRST! That way you can not accidentally short the positive terminal.

 

[Henry Boyd]

Thanks Lazy. I just read in another forum (Chaparralboats.com/boat talk), one of the contributors said "There is no such thing as a 'House Battery' on a Sea Ray". Wyrman, on this string says he never turns his batteries off. OK, on the hook, engines off, radio, fridge, and cabin lights on. Battery switches 'on', 'off', 'both' ,ect??! what if any effect is there on the batteries?

That is a correct statement about many of the Sea Ray models. That is all of the batteries provide starting power for the engines, and some them also provide power for house loads. The typical set up is one engine has its own starting battery and that only starts the engine. (If a generator is installed it also has its own dedicated starter battery.) The other engine will have two batteries in parallel. Besides starting that engine these batteries will also service the house loads.

Boats that have true house batteries are set up so that each engine has a dedicated battery only for starting and running that engine. The starting batteries are all charged either by the individual alternators, or a dedicated charger connected to shore power. House loads are wired to a battery bank that is in no way connected to any of the starting batteries. This bank will have its own shore power charger.

 

[Njlarry]

Has anyone rewired so each engine has its own single starting battery and two deep discharge batteries are in parallel for house loads? AC battery charger does charging for all three, engine alternator charges only its own starter battery. Not sure how both alternators charge house also. House bats can be deeply discharged starter bats can be selected to deal with short periods of high amps.