Duh.
My point exactly. There is no need to qualify that since you don't get double the amp hours when you use a pair of 6Volts to make a 12V 210amp hour battery in a series connection as ALL RV users do.
I saw a posting about this sometime in the past few months. One of our fellow MBS drivers had removed the top of the step, added a bit of spacing on top of the walls of the battery compartment, and then reinstalled the top of the step.
As reported, the amount of additional height required wasn't huge and the difference in step height wasn't thought to be a problem.
Dave
I cut and installed a hinge on my Class C understep battery compartment. It allowed me to install two AGM 12V batteries. Two Lead-acid 6 volt batteries are of similar size.
Mark