Adding an additional house battery?

[Live a Little]

Hi guys and gals, I am new here obviously and have an important question. I currently have a 1993 370 Sundancer that should have an extra house battery. It currently has 4 batteries (1 or 2 starting batteries?, 1 battery for generator and 1 house battery) and I would like to add another house battery. Each 7.4 litre engine has an alternator and I would like to understand how the charging system works and what is involved with adding another house battery. I will be putting in new batteries and a new charger, ProMariner ProNautic 12.50P. When plugged into shore power does the original battery charger charge all 4 batteries? If so this would mean it would be a four bank charger. I am very confused on how the charging system works and haven't been able to find anything on line that really clarifies my confusion. I have been told that I can add another battery if I have an additional bank to charge it. However any battery charger that I have looked at and has been recommended to me, only has 3 banks and I have yet to find one that is 4 or 5 banks. Can you please explain to me in detail how I can accomplish adding an additional 31 series house battery? Thank you.

 

[ranger58sb]

I'd have guessed you have three banks:
- one with 1 battery to start one engine and service half of the house and a bridge load (electrics?),
- one with 2 batteries to start the other engine, support the half of the house that has the fridge load, and remaining bridge loads (electronics?),
- and 1 to start the genset.

If so, you'd likely have one 3-bank charger.

If you really have an additional stand-alone house bank, I'd think that different from a standard Sea Ray implementation... although I don't have much depth with the brand yet. A separate house battery would imply you also have a second charger somewhere.

So there are things like that you can check...

-Chris