Laser ballpoint pens are laser pointers that also have a ballpoint pen ink tube so that the pointer can double as a writing tool. Many people find this combination useful -- especially teachers and presenters who write notes while using the laser pointer during lessons and presentations. The typical design of a laser ballpoint pen is a barrel shape that looks like a writing pen with or without a cap. Because of the shape of the design, manufacturers usually power the pen with button-shaped batteries that fit inside the cylindrical barrel.
Hold your laser ballpoint pen by both ends of the assembled barrel.
Twist the two sections of the barrel -- usually near the center or upper half of the device -- in opposite directions until the barrel separates.
Check inside each section for the batteries. Set aside the section that doesn’t contain batteries.
Tilt the section containing the batteries over your hand to slide out batteries. Make certain beforehand to note whether the positive or negative end of the top battery is pointing out. As you slide the batteries out of the barrel, note the orientation of the other batteries.
Insert the new batteries -- matching the orientation of the old batteries -- and then screw one barrel section into the other section to reassemble your laser ballpoint pen.