I know the grounds for the battery go to the engine however Im planning on relocating my batteries to the bed (mainly because a co-worker gave me 3 group 31 optima yellows and clean up the engine bay some) so was wondering if instead of running the cables straight to the engine if I could ground them to the frame and then run a ground from the frame to the engine on either side? Failing that anything wrong with just running 1 ground cable from the batteries to a engine ground then running a cable from there to the other ground(s)?