Wiring for a dual battery setup

[Mullady76]

Guys,
This spring I'm going to be replacing / upgrading the batteries on my 200 CCP.  Right now I have (2) group 24s tied into a Perko 1-2-all switch. Battery #1 is just for starting the engine and batt.#2 runs all the electronics and lights. All the electronics and lights are on separate fused switches and tied directly to batt. #2.  The charging lead from the motor goes to the Perko switch so I can charge either battery, but its always set to charge batt.#1 and an ACR charges the house battery.  Is this an acceptable setup? 
I would also like to up size the house battery.  Would I be better off going to a single group 29/31 or a pair of group 24s?

Thanks, Sean

[Capt. Bob]

Sean,
If it's wired correctly then that is a proper set up utilizing an ACR.

More complicated but same theory:
https://www.google.com/search?q=Dual+battery+ACR+and+perko+switch&tbm=isch&tbo=u&source=univ&sa=X&ei=6nf4VN3PPMHCggSDgoPADw&ved=0CCcQsAQ&biw=1366&bih=643#imgdii=_&imgrc=ioKAg8CzAr7JDM%253A%3BVwR6cDIbQEpeJM%3Bhttp%253A%252F%252Fbluesea.com%252Ffiles%252Fresources%252Fnewsletter%252Fimages%252Facr_wiring_diagram.jpg%3Bhttp%253A%252F%252Fwww.performanceboats.com%252Fpb-open-water%252F42272-dual-battery-question.html%3B502%3B314

Here's a wild looking hand drawn one that seems to fit your application (more or less) if you wanted to have two house batteries.
http://www.moomba.com/msgboard/showthread.php?14636-Wiring-Diagram-for-Blue-Sea-Add-A-Battery-%28Switch-ACR-Combo%29

As to battery size:
I've used Group 27s for years and never seemed to need more but that is just based on my style of use. I have added a new battery late last year and went to a Group 31. That size fits in a 27 box but is very heavy and probably overkill for your use. If you have had good use out of the 24s then stick with them but upgrading to a size 27 will only hurt your cash flow. I'm not sure a 27 will fit a 24 box though. Space wise would seem to be your limiting factor.

Good luck.

[Mullady76]

Thanks for the info. Capt. Bob.  The only difference in my set up is the positive distribution panel is hard wired to the house battery instead of the 1-2-all switch. I guess the thought was that you could never run down your starting battery unless you left the switch in the "both" position. 
I will probably stick with a group 24 for the starting battery and go with the large house battery since its only a few $$ more.