We fitted a smaller battery on our bike, and them mounted the RapidBike module and the smaller battery in the same space as the standard battery previously took occupied...
I routed mine from the left side of the bike to the right. Mounting the box on the inner fairing sail and had plenty of wire to run to the battery. Ran the main harness through between the radiator and the front head. Make sure to use a piece of cardboard between the cable and fins or you will smash the heck out of the radiator.