Camera wiring question

Hello again I have another question for you all. I am doing the electronics on the plane I had a question about the other day, I saw on one of the FliteTest episodes where Chad talked about making a wiring harness to hook up a 12 volt camera outfit to the flight battery's balance plug. In that instance he was hooking up to a 3S battery so I can asssume he used all the leads. Well I am running a 4S and wanted to know, if I only hook to 3 of the positive leads will I cause a problem with the battery balance or will the camera not draw enough power to cause a problem with the balance. I could run a seperate battery for the camera but would rather not. I would appreciate any advice.

Thanks David