Just my 2 cents
I have a 2017 Thor class C. It also had 2 12v batteries under the step. When installing my solar set p I knew I needed more batteries. For the life of me I could not any 4 agm’s that where short enough to fit under the steps and still be able to get a wrench on top of them to make all the connections.
My solution was installing 2 Life Line 6volt 300 ah in series. I have them laying on their sides. Perfect fit. So if you can live on 300ah of back up power that my work.
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