by erbster » Sat Apr 18, 2015 8:01 am
Sounds like your batteries might be due for replacement. What charger do you use? You might be able to recondition the batteries if they have not been properly charged (or left flat). I think two batteries is overkill for a CC (too heavy).
I fitted a 110Ah battery to Aurora. We have LED cabin lights, GPS, VHF, nav lights (rarely used), depth & log. The VHF is pretty thirsty, but doesn't get a great deal of use. Might fit a tiller pilot. The biggest drain for us is gadget charging. An iPad draws 2A when charging! Consequently, I have fitted two "roaming" (ie not permanently fixed) solar panels.
My initial plan (before solar panels) was to go about 4 days without needing shore power. That was fine. We had nearly 4 weeks in Sweden last year and did not use mains at all- the solar panels were used intermittently (not usually whilst sailing) and there was never any worry about low battery, despite constant use of iPad whilst sailing and major gadget charging by family.
In summary, it depends on how you want to use the boat. You might be on a mooring, in water all season (in which case, a small battery, easily removed for charging might be best). If you use marinas most of the time, then you can use shore power and a large battery is not needed. If you want to be away from mains often (nights at anchor anyone?), then a big battery is an asset.
I told my wife it makes the boat heel less....