The original plan was to have the wires free floating in the model, but that posed a fire hazard; if any live and ground wire touched, it would heat up and potentially catch fire. The potentiometer was also not part of the original plan, but it was needed as the batteries were too powerful for the lights and would burn them out. The reason that I didn't want to swap to smaller batteries was because of safety; it is safer to have the battery pack running at far below its max capacity, as it keeps the pack itself cooler and limits the chance of a fire.
