Perfect mate, you are a legend! Thank you for the information.
I believe the best route would be to go parallel, creating a 12s12P, via a 12s5p Main Pack + 12s7p Range extender pack in parallel.
If i use Liion cells, both packs added, Main 20AH and Extender 28AH, this would be a huge 48 AH pack.
Then no need to worry about range anxiety anymore… and can unplug the range extender whenever i go on shorter rides