Charger

Health and HEV Suit Chargers are wall-mounted devices that give a limited amount of health and power. They are found throughout the Black Mesa Research Facility and, later, in Combine-controlled locations.

Overview
The chargers can be used by staying near them and pressing the  key. Whilst being used, their power drains and eventually they will stop healing or charging. In Half-Life 2 and Half-Life: Source they will also stop when the player reaches full health or power.

In Half-Life, health and HEV chargers are the primary source of health and power throughout the game. Medkits and batteries do not provide enough health and armor to be an effective long-term source of healing and protection.

In Half-Life 2, however, medkits have become the primary healing item, giving 25 health points. Medkits are also considerably more common in Wasteland areas outside of Combine control, whereas chargers are common within City 17. The HEV charger is still the primary source of power, due to batteries being comparatively uncommon.