Car battery

The car battery is a physics prop featured in Half-Life 2, which is used in an electricity puzzle during the chapter Sandtraps.

Half-Life 2
During the chapter Sandtraps, several car battery props are located in inconspicuous areas near an abandoned building. The building, seemingly over run by the Combine, is just off of a road blocked by an electric gate.

The aim of the puzzle is to collect enough batteries to send power to the gate and unblock the road.