Power drain

The Power Drain is a short-range, tactical, energy sapping device which made its debut in Halo 3.

Function
The power drain creates a short-range Electromagnetic Pulse (EMP) effect which causes disastrous failure of powered field systems within a set radius, and is designed primarily to interfere with common varieties of electrical field-based shielding, vehicle and power generation. It also has a damaging effect on biological systems and can wound or kill most bipeds in its resulting explosion. Essentially, the Power Drain is like a reverse Regenerator; instead of energizing a player's shields, it causes any player's shields within the area of effect to drain away quickly, making them vulnerable to harm. The self-destruct explosion after the activation of the Power Drain will not kill you (If you were at full armor health previous to deploying it), but will take your health to critical levels. The Power Drain can also disable vehicles via EMP, rendering them unable to move (but the vehicle can still use and aim its onboard weapons) when they drive or fly through it and even about 5 seconds afterwards. If a Regenerator and Power Drain are deployed in close proximity, the Regenerator will stop working. The Power Drain, like the Bubble Shield, Trip Mine, Radar Jammer and the Portable Gravity Lift, are all in the category of equipment and can be deployed using the "X" Button. It activates shortly after it is thrown - just enough inactive time to travel away from the user, leaving them unaffected.

The power drain can even disable non-drivable vehicles like the Scarab as seen in TGS Demo Part 2, but the weapons systems will still be active, as in any vehicle. In fact, the power drainer will affect any device that runs on any type of energy within its radius in game.

Tactics

 * This equipment will stall a vehicle's engine, but the weapon/weapons on the vehicle still work, working quickly with the Power Drain and a weapon or grenade is the only smart way to kill everyone inside a turreted or armed vehicle.
 * This is a good piece of equipment that is well used in conjunction with headshot weapons such as the Battle Rifle and Magnum.
 * This is the piece of equipment that is a must need when outnumbered, once drained, the whole group becomes a big one-hit-kill target.
 * Bubble Shields cannot block the Power Drain from entering, so it's a good idea to throw one inside of a Bubble Shield while your enemies are inside of it. Also the effects of the Power drain will be contained by the Bubble shield.
 * Deploy this equipment near a popular sniper position or an area where people land after they get off of the Man Cannon, after that, its another one-hit-kill target.
 * Try keeping some distance between you and your foe when in combat (online), as when in close quarters battle (CQB), they tend to use power drains.
 * While it is pure luck when it happens, it is possible to splatter an opponent with a Power Drain by tossing it down a hill and it hitting them while it is rolling.
 * The Power Drain's ability to render vehicles temporarily useless is only featured in one other weapon in Halo 3; the Plasma Pistol's overcharged shot.

Spawns

 * Avalanche- There is one Power Drain each located near the large Mancannons of each base where the Mancannon leads players inside the top of the base.
 * Blackout- The Power Drain is on the floor that is above the tunnel hole where the Shotgun spawns.
 * Cold Storage- The Power Drain is on the second floor where it is above a Teleporter and Assault Rifle spawn room, and also in between another Teleporter and Plasma Rifle spawn.
 * Construct- There are two Power Drains on the map. One is located at the bottom floor, very close to the Yellow Gravity lift. Another is located at the column where the Energy Sword spawns on the map.
 * Epitaph and Epilouge- On Epitaph, the Power Drain is located at the lower floor where the large Gravity Lift resides. On Epilogue, it is located at the higher floor. (Originally the Needler spawn).
 * Foundry- The Power Drain is located on top of the nearest center-positioned Box from the bases, along with the Plasma Pistol spawn.
 * Ghost Town- The Power Drain is located on the upper floor where the main building is.
 * High Ground- The Power Drain is located at a balcony near the room where the base's Needler spawns.
 * Last Resort- The Power Drain is located inside the Fortress, near where two Assault Rifle spawns.
 * Narrows- (Updated version) There is a Power Drain near the each of the base's Mancannons. (Older version) The Power Drain is located near the Yellow base's Mancannon.
 * Sandtrap- Two Power Drain spawn under the structure where there is a Gravity Lift and where the Rocket Launcher spawns on the map.
 * Snowbound- The Power Drain spawns at of the Blue Lower Base.
 * Standoff- There is a Power Drain each inside a base's lower room, the room where the controls for the Window shutters and another Entrance gate are.
 * The Pit- There is a Power Drain on the upper floor just outside the room where the Energy Sword spawns outside the map.
 * Valhalla- One Power Drain spawns at each base's upper floor.

Trivia

 * The power drainer lasts approximately 6.5 seconds.
 * It shares many physical similarities with the Radar Jammer and Flare, with exception of a blue glow instead of a red/yellow glow.
 * In the Multiplayer Beta, the players got the Power Drain and the Bubble Shield mixed up and ended up draining the shields of friendlies and shielding enemies. The Beta version when deployed, was a glow of a much lighter blue color and had a larger effect radius which had a cloud of haze around the edge.
 * When the Power Drain is thrown at the generator of a Bubble Shield, the Bubble Shield will actually move over a few inches when hit by the Power Drain.
 * It may also be used as a grenade by throwing it at a group of enemies, draining their shields and after a little while, the resulting explosion can sometimes kill the shieldless foes if they are close to it.
 * On the Halo 3 campaign, Brutes will occasionally use Power Drains even though they cannot aim properly to deploy near you.
 * In the Campaign, it is possible to die from staying within the Power Drain's "field" (It will drain your shields and the explosion will kill you). However, in Multiplayer, it may kill you at a certain point (If you have received some damage, it is possible), however, it will still drain your shields.
 * The Power Drain can be thrown through the shield doors on all levels and through a deployed Bubble Shield. This is a very efficient way to root out campers.
 * If you fire a Spartan Laser while near a Power Drain and view the beam in Theater mode from within the Power Drain's field, the beam will be a blue-white color.
 * A common strategy on Valhalla involves throwing the Power Drainer out the man cannon to intercept a low flying Banshee. The Power Drainer's relatively large damage radius will normally result in the disabling of the Banshee's engines for about 5 seconds, during which it can be destroyed/boarded.
 * The effects of the Power Drain can also pass through walls and floors so simply jumping to the floor on the bottom after an enemy activates one may still strip your shields through the roof if you pass through it.
 * If both Regenerator and Power Drain is deployed, your shield will be reduced even though the regenerator is near.
 * When the power drainer disables a vehicle, blue sparks can be seen on it indicating the vehicle will not move. These sparks can also be seen when the Plasma Pistol disables a vehicle and if the affected vehicle is destroyed.

Images
 Image:Powerdrainhud.svg|The Power Drain HUD icon. 