Need Some Advice Regarding Batteries

[willyshields2]

I just bought a 1987 Carver Montego 26, It came with two batteries, both flooded type one a 650 amp and the other a 750 amp.
I plan to live aboard in the summer time in the Kawarthas in Central Ontario. My thoughts are that I should have more batteries. I am leaning towards 2 Optima gel cell deep cycles (blue top) for the house batteries and another Optima (yellow top) for the staring battery.
Are there better options out there rather than paying out 300$ each for batteries? (The yellow top in my 4x4 cost me 280$.)

[Mark Zarley]

Just wondering about your summer lifestyle. Will you be in a marina most of the time ? If not what are your battery charging choices?

[willyshields2]

Yes, marina most of the time hooked up to 30 amp hydro. Some weekends out fishing, expect about 10 overnights on anchor.
I have a solar trickle charger and can buy a decent battery charger IF I have to.

[Mark Zarley]

Hooked up to 30 amp will supply all your needs , battery size un important. Its the overnights on the hook you need to "size your batt " for. Here is a simple formula take your total amps per hr used (anchor ,cabin lights,refrig,radio (VHF & am-fm) anything that is a draw on your house batt. Mutiply by the number of hrs between charging cycles (starting up the eng or firing up a small gen). This will give you amp hrs. This number should be 30 % of the total amp hr of your new batt. So if you use 90 amps hrs between charges you need a 300 amp hr batt. Caution there is a big difference between "starting amps or CCA cold cranking amps" and "amp hrs".

[willyshields2]

Thanks for the info, Mark.