Command Chip Power Source

Where does the command chip draw its electrical power from? In a space plane I'm currently flying in orbit around Droo, I see that the battery level is at 100% despite my being on my 3rd orbit and I'm not using solar panels. The nose cap on the plane is designated as a battery. The plane also has a gyroscope running at normal power. It seems there should be some power drain from the gyro and the command chip.