That's going to have to be the mother of all batteries to supply that much power for an extended tx. I like the plan.
As someone who did all remote broadcasting during his career you're going to run into people from time to time that A) Wonder what the heck that thing is?, and B) Have bad intentions towards you.
With the first, a handful of stock stories will work, but if you're not a ham, don't say that you are. I knew a guy who tried to pull that with cop who turned out to be a ham and asked him for his call. From what I recall, he had to tell a real whopper to get out of that one.
With the second group, if you operate in a state where open carry is legal, seeing a pistol on your hip will discourage most of them. I know seeing a large skinning knife on my hip discouraged some weed growers who ready to put me in the ground to fertilize next years crop when they were walking in to check on a crop. Once we got to talking it turned out two of them knew some cousins of mine. They then tried to tell me they were looking for a horse! In a State Forest in the dark, no less. I had run in with a nut a couple of years later that thought I was spying on him with "surveillance equipment". When I stood up and he saw the pistol, he went back to his campsite and shot me dirty looks.
Another reason for a gun in my region was it's overrun with bears. Most will beat it when they smell and hear you, but garbage bears are different. They see you and your trash as source of food, especially if they've been fed by people staying in the general area you're tx'ing from. They have no real fear of humans and can be aggressive. A reliable shotgun loaded with slugs close at hand will turn the trick on our local black bears. I always took an old 12 ga. pump went I went to a place where garbage bears were likely to be. One thing with guns, if you're not prepared and willing to use one, leave it at home.
Two bad run-ins in just over a decade of broadcasting at least twice a month from the boonies isn't much to sweat. Just be aware of the people that may be around and how they behave and you'll be fine. Most of the people who approach you fall in the first bunch I listed above, they're just curious.
Good luck, and enjoy transmitting from the sticks. The pre and post transmitting dx is great and if you come from a light polluted area, the show in the night sky is the best of all.