The RV's on Rockit engage a busbar as they enter the station, the bus bar being very similar to the dark rides. The busbar runs the entire length of the station. It is used to activate the compressors on the car to unlock restraints and verify restraints are locked. It is also used to carry the dispatch enable signal from the RV to the ride control system when the loader tags the back of the car (much like Forbidden Journey). All of this is run off of voltage from the busbar in the station.
Another set of busbars are used for charging the RV. The most common way to do onboard audio and whatnot in the industry is for the power source to charge a set of resistors on the RV. The reason for using this instead of conventional batteries is that a bank of resistors is significantly lighter than a set of batteries. Batteries also take longer to charge, whereas a bank of resistors can simply be "zapped" within about 5 seconds. Yes, batteries would last much longer, however, the RV only needs to hold a charge for a few minutes at a time, because it gets zapped every time it gets to the station.