There is enough room close to the battery area depending on the size of battery your adding. You can build a box between the electrical and motor (I would add a heat shield also just because), If a 2 seat model there is a lot of room in front of the rear wheel area to add a box for it. Once you get the machine and get to look around I don't think you will have any problems finding a suitable placement for it. What you have for cable length and size of the battery might be the deciding factors.
I ran the wires across the front of the motor and zip tied them to the frame (which would be behind your knees when sitting-under the seat of course). I used a battery mount to tie it down to the aluminum metal plate. Ill see if I can get a picture.