Batteries in parallel and series

Here's how to interconnect multiple 12V batteries together for the proper current balancing between them. The diagrams are for 12V batteries, but for a battery bank made up of 6V batteries just substitue two 6V batteries connected in series with each other to represent each rectangle in the diagrams:
http://www.smartgauge.co.uk/batt_con.html

Only way to improve would be to connect the three pairs to a bus bar to distribute the power.
For practical RV use the diagram is fine and US Battery recommends same.

This works well enough in practice, but it isn't theoretically perfect. The middle pair of batteries shares a bit less of the load than the outer two. Probably the simplest way to get theoretically perfect balancing is to run each of the three battery pair leads separately to a bus bar or other common connection point, using equal length wires for each battery.

In practice, though, I'm pretty sure what's shown would work very well.

Both drawings are of the same hookup and will work well...

Correct. That is what I drew. Is there a “better” way?

POS to Coach from one end
NEG to coach from opposite end

Balanced draw and charging