I have a 2005 Nitro 929 and I was wondering if anyone out there has added an additional battery to the back compartment. Currently I have two in the back compartment and one each under the storage areas. I am contemplating adding another cranking battery run in parallel with my other cranking battery so that I have sufficient power to start my boat and run my electronics.
I haven't done that with the 929 but ran 4 in my old 640 for the same reason you stated.
When I switched to the 929 I run a 80lbs TM so added 3 new deep cells all the same kind and size and haven't had an issue running out of juice. Might check into doing that before adding another 50lbs battery. I do keep a jump box on board as well just in case
Good Luck
Fogy