A portable computer may include battery indicator light structures. Battery status information in the portable computer may be presented to a user using an array of light-emitting diodes or other light emitters. Light-emitting diodes may be mounted on a printed circuit board.A stiffener may provide the printed circuit board with rigidity. The printed circuit board may include a connector that allows the board to be connected to a main logic board. A switch on the printed circuit board may be actuated by a power button on the portable computer. An opaque member with an array of holes may be used to reduce light bleed between adjacent light-emitting diodes. Diffusing plastic may be mounted within the array of holes. Bumps in the diffusing plastic may mate with corresponding holes on a portable computer housing.