first, read this, both parts 1 and 2:
The 12volt Side of Life (Part 1)
this is a good place to learn how your batteries work and what they work.
i'm assuming your Sunseeker didn't come with a generator.
and that of the two batteries, one is for the engine and the other for the house.
then the ways to extend your battery's power are see if you can add a second house battery. LED's will definitely help but the biggest power drain will be the furnace.
getting solar panels or a generator will be the next thing.
for us, a Honda 2000 was better, since we almost always dry camp in forested campgrounds and we can run everything except the a/c with it.
remember, solar and batteries will NOT run the a/c or the microwave or the 110v outlets. you'll need a generator for that. and you'll need a more powerful generator if you want to run the a/c.
lastly, the best choice for a generator, are the much quieter inverter generators, such as Honda, Yamaha, Kipor and others.
and Zoe the Wonder Dog(R.I.P.)
'07 Roo 23SS pushing an '07 Chevy Avalanche
Equalizer WDH and Prodigy BC