I started the vehicle and it displayed a message on the infotainment system screen that the system had lost power. I believed that this would only affect the radio functionality which I was not concerned about immediately. I placed the vehicle in reverse and I accidentally backed up into a parked car. At no point before the accident did I realize the rear camera did not work and the collision assistance sensors did not function. I believe if the collision avoidance system was working correctly my accident would have been prevented. I have come to depend on the safety features of this vehicle. I know that this is not an issue with my car battery as I recently had a Honda dealer install a new battery prior to this accident and the vehicle started normally.