Is there a difference between the OEM cord and after market, except the $20-$40 price difference. Also a folding or portable solar panel is in the future, I need to get this and prove it out before SWMBO goes out to use it. Yes you are correct, right now is camping and in a few years at retirement the travel trailer will be the house for a few yearsI think most here are suggesting batteries bigger than you need. I use a 12v, 20Ah lifepo4 battery for my CPAP when camping and for power outages. Get the OEM 12v cord, not the after market one. A folding 100w solar panel and PWM charge controller should keep it charged if your usage is anything near mine. Remember folks, he is camping so it needs to be portable.