Charger

Health and HEV Suit Chargers are wall-mounted devices that, when used by the player, give them a limited amount of health and power points. They are found throughout the Black Mesa Research Facility and later found in Combine-controlled areas and buildings.

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, 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.

Health Chargers
In both games, Health Chargers are scattered throughout areas, and are placed around for the convenience of staff in high-risk areas, such as in areas with dangerous creatures or machinery. The Half-Life 2 variant has a blue line that gets smaller as more supplies are used up, as well as a spinning disk which twirls inward continuously until health liquid is depleted. The Health Charger gives 50% health each time. On the other hand, the health chargers in the Source high-definition pack have a hypodermic needle on a mechanical arm connected to a small reservoir of medicine. Whenever a user is nearby, the arm automatically extends in front of them.

HEV Chargers
HEV Chargers appear in both games, but for completely different reasons. In Half-Life, there are dedicated HEV suit chargers scattered throughout the facility, hinting that HEV usage was widespread throughout the Black Mesa Research Facility. In addition, generic power sources (Ohm's) can also be used to draw power for the HEV suit, though these only appear in the more-neglected areas of the facility. Dedicated PCV chargers are made, but they only appeared in key parts of the facility controlled by the military, mostly after the Resonance Cascade. In the neglected parts of the facility, there are old HEV Chargers that have a different shape. These usually work like the "newer" models, but some are prone to exploding. There is also a charger in the multiplayer map "stalkyard", this one is like the old Blue Shift HEV charger (with only the upper texture different), but is unusable.

In Half-Life 2, "HEV" chargers are actually generic power sources used by the Combine. The Mk V HEV suit has been designed to specifically accept power from these sources. The only "original" HEV Suit charger is a front plate that can be found in Black Mesa East and the White Forest base. All types of power chargers have 75 percent power.

When the HEV suit is powered up by Dark Energy at the end of Half-Life 2 and during the Citadel in Episode One, the HEV suit can utilize HEV Chargers much more efficiently; it can easily go from 0 to 200 armor points without draining most of the charger. In addition, HEV Chargers can also heal a person while the HEV suit is powered up. However, this is only the case when the suit is charged with dark energy, doubling its power capacity. Finally, the charger in the source high-definition pack involves two spinning power coils, with, like the health charger, a robot arm with electricity running through it.

Behind the scenes

 * In Half-Life, Chargers are actually brush-based entities that can be applied to any surface, but are dedicated entities in Half-Life 2. The brush-based version remains in the Half-Life 2 engine, but is not used. The WC mappack maps make extensive use of the brush-based entity version, they look like updated versions of the Half-Life chargers.
 * Combine Chargers bear several markings, mostly consisting of Arabic numerals.
 * The Health Charger has a red cross on a white background, for easy identification, white "AIDE" and "314 - 11:43" under it, as well as the numbers "88000-001 1 08" and "0088-D" on the bottom of the device, "0088-D" being accompanied by an indecipherable text. The Half-Life 2 Beta Health Charger model features "COMBINE HEALTH" instead of "AIDE".
 * The Suit Charger has beige colored parts, with on them the word "POWER" and "314 - 11:44" right under, interestingly being dissimilar to the Health Charger numbers from only one cipher. The numbers "88000-001 1" and "0088-D" are also present on the bottom of the device, the "08" from the Health Charger being removed.
 * In the Half Life 2 Pre-Release sound files the Combine Health Charger is referred to by Dr. Kleiner as "Combine Auto-Medic"

Trivia

 * Health and HEV chargers can be placed in Team Fortress Classic maps. They have much larger reserves than their Half-Life versions.
 * In Half-Life multiplayer and Half-Life 2: Deathmatch, HEV chargers give only 30 armor, and health chargers will give only 30 (50 in Half-Life Deathmatch) health.
 * In Half-life 2: Deathmatch, in the map " ", a Combine dispenser can give 200 armor and health points like the Citadel chargers.
 * In older versions of Half-Life, using HEV or Health chargers when empty would reset their timers, thus potentially extending their empty time. However, this has been fixed in Half-Life: Opposing Force and Half-Life: Blue Shift.

List of appearances

 * Half-Life: Day One
 * Half-Life
 * Half-Life: Uplink
 * Half-Life: Opposing Force
 * Deathmatch Classic
 * Half-Life: Blue Shift
 * Half-Life: Decay
 * Half-Life 2
 * Half-Life 2: Deathmatch
 * Half-Life 2: Lost Coast
 * Half-Life 2: Episode One
 * Half-Life 2: Episode Two