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Solar is super simple to install with minimal knowledge and a youtube video.
Your lead acid battery should be good for 3-5 years. Run it 'til it dies, then replace with LiIon. That's what I plan to do. If you run it fully down to 0%, they'll die much quicker then time to upgrade!
I have the Victron battery monitor if you're interested, I think I posted about it in the van thread? Or maybe this one? I dunno, lots of these going around.