A “suspicious” device that prompted the evacuation of a Mercer County school turned out to be a battery pack.

Hightstown High School was evacuated Monday after an object with exposed wires and computer circuitry was found inside the boys’ bathroom. Officials were not sure what the object was at the time and evacuated the school as a precaution.

Hightstown police now say that the device was an exterior battery pack that was missing its case due to damage. Police say that a student was using the battery back when it malfunctioned and started to spark. The student panicked, and tried to dispose of the device in the bathroom, according to police.

Police say that the student cooperated with the police investigation and did not have any malicious intent when disposing of the device.

Officials say that evacuating the school as the right thing to do until they determined what the device was.

No charges are expected to be filed.