TraciK wrote:
... I was thinking if we got a battery we could run the blower and lights off of it.
Do you imply that there is not a house battery? Most TC's have at least one... how long you can run a heater blower (which take a lot of power compared to other components) depends on many factors such as how much volume of camper you need to heat, how warm and often the blower runs, how many batteries or other sources of power you have... but yes, a house battery will allow you to camp off the grid in comfort to run the interior components except for AC and MW.
Here are some good information articles that can get you up and running for your needs:
The 12volt Side of Life (Part 1)The 12 volt Side of Life (Part 2)