Hi Randy, curious. What do you have now in terms of total amp hours and why do you need more? Our boat has a house bank of two 8Ds giving us about 250 AH of usable power. That usually will last us two days on the hook with both reefers on and other stuff. At that point I run the generator for about 1.5 hours to top off the house bank, heat water and some cooking. This is our routine during a typical two month cruise where we spend most of our time on the hook.Has anyone added extra batteries on a Hunter 376.