The battery system used in the PCK-4 is standard alkaline AA batteries. The batteries will operate the scoreboard for approximately 50 hours of clock running time, which is the entire season in most cases. A replacement set of batteries for the next season costs about $6.
Contrast this with any other system that use rechargeable batteries that must be plugged in before every use. Invariably, someone will forget to plug the unit in and it will die in the middle of a game.
One design goal of the PCK-4 was to have a battery system that required no attention for the entire season. You just take it to the game and use it--no fooling around with "plugging it in". The unique design of the displays and electronics in the PCK-4* makes the outstanding battery life possible.