It is pretty standard in a 3 battery setup to wire 2 batteries together as the "house bank" and one battery kept separate as the "starter". The three are then typically wired to a 4 position switch with off, bat1, bat2, and both as te 4 positions. This lets you run your house batteries without fear of runing down your starter and lets you use your house batteries to start if you should ever have te starting battery fail. There are also more complex alternatives to this that are even better...check out: http://www.westmarine.com/webapp/wcs...terysystem.htm
For a pretty good run down on thhe options.
03-18-2006 05:33 PM
I have a 1980 '37. I have added 3 group 27 batteries to the original one group 27 and one group 24 (under the galley step). One of the batteries is located in the storage area under the starboard saloon seat. The second is located in a compartment created by opening up the area under the galley stove. The third is in a shelf in the forward hanging locker. The first two batteries are connected to a typical 1,2,& all switch with the common output connected to the common pole of the original battery switch. The third is wired in parallel with the original #2 battery and essentially forms a single battery as it has no separate switch. The battery in the forward hanging locker is also the primary battery for my anchor windlass. My system is not bullet proof. It does allow each battery to be isolated from the system if desired by manually setting the switches.
03-16-2006 07:09 PM
irwin 37 cc
anyone have any ideals on how to install a 3rd battery on my 37 that is the correct way to wire ????