Sea Ray 360 Aft Cabin Batteries

[JerryShields]

I bought a 1985 Sea Ray 360 Aft Cabin last fall and am now summerizing the boat here in Ontario.

I am confused about the battery configuration....

There are 4 batteries. One is dedicated to start the generator and there are 3 between the engines.
The 2 forward batteries between the engines appear to be both house batteries and engine start batteries.
The aft battery seems to have no purpose.
It has several light duty wires coming off the posts but nothing heavy enough to start an engine.
I have connected just that battery and nothing on the boat will turn on or make use of that power.

Any idea what this fourth battery could be powering??

Thanks - Jerry

 

[Flabby]

Hey Jerry,
Congrats on the boat. I have the 1987 360 AC. Clueless on the 3rd battery, but mine all seem to be in series to assist in the emergency start. I'm looking for parts for the air horns and I'm about to start rebedding the deck hardware. Do you know if the cleat bolts are captured or will I have to cut the interior to get a wrench on them?