What is typical install on a O/B, single or dual batteries?

I run 2 on my 24 pantera

Previous owner had no stereo or Gps so he had it rigged w/ one group 27. I was thinking if I run a 2nd ,to use a smaller group 24 Deep cycle just for accessories.

YES,

I run 2-24's, one cranking, and one dual purpose. I read somewhere once that your batteries should be of similar type, not sure why, charge rates maybe. That is why I don't run a true deep cycle for the stereo/accessories. What outboard are you running? Some just have a stator for charging, mine(3 liter merc) has a true alternator. Where in CT are you? I grew up in Danbury.

Run 1/XS Power , XP2000 ...Group 24 2000 Cranking amps and 150 min reserve power , 51 pounds and I can sell you one for $299 shipped to your door .

Yeah, but I can buy 4 walmart batteries for that$$

you can .... But an extra 150Lbs in a 24 can be 2-3 mph's

Will check out the XS XP2000 battery , sounds pretty good. My motor calls for a minimum of 900cca , so that would work.
Thanks for the info.

I just had one battery in my 24 I/O. GPS, basic stereo (not used much). Never any issues.

Just bought a 1050CCA { group 27} with 182 reserve minutes at 25amps [56lbs] its a Sea-Volt brand Starting battery from West Marine. Thanks All for your input/advice