I have uploaded my build pics onto toxic website, at their trial run at leicester they were perfect
they are 9 cell packs and i used 4 packs, in the pics the battery is 9 cells side by side to make
2 battery packs in 1 polycarbonate piece.
at the event I was using about 55% - 60% of the batterys, I could get away with 3 packs but will
leave 4 in as ive got loads of power spare now.
the pics ore here -

http://www.toxicrobot.co.uk