The Shield Battery is an uncommonly used Protoss defensive building which can replenish the Plasma Shields of an injured Protoss unit. It generates Energy which can be quickly converted into Shield hit points on nearby units, whether it be a single unit or a group of them. When constructed, the Shield Battery starts with 100 Energy, and each Energy point can heal two Shield points. Unlike the Medic's heal, the unit receiving the Shield recovery cannot move or attack while it happens.
Because of their low cost, Shield Batteries can be effective in supporting Carriers and Archons, both of which have many shield points. Due to lack of mobility, Shield Batteries are most useful when placed in direct support of a defensive position, such as at the top of a ramp the Protoss player is trying to defend. Shield Batteries are also sometimes used in PvP early game situations when a defender needs to hold its base against a large number of Zealots. In uncommon cases, a Protoss player Proxying a Pylon near an opponent's base will proxy a Shield Battery to make the attack more powerful. On maps where starting locations are close to each other, (as on Hunters), one can build a Shield Battery to help you contain an enemy.
Shield Battery usages are situational, meaning that the Protoss player often cannot predict using them beyond the spur of the moment, an example being when a tough fight is expected. It is not viable to put Shield Batteries well in advance and to plan on using it. Because going both Photon Cannons and Shield Battery consumes too many minerals, the Protoss player will generally opt for one or the other. Opting for a Photon Cannon with range will also enable the Protoss player to use the required Forge for a +1 upgrade to kill Zerglings with only two hits. Photon Cannons may be overall better in defensive situations than Shield Batteries, but Cannons require a significant amount of time to build. A Forge requires 50 seconds to warp in, as does the Photon Cannons. A Shield Battery only takes 30 seconds to warp in, which is about a minute faster than making a single Photon Cannon.
On certain maps, Shield Batteries become even more viable. On maps without a Vespene Gas Geyser at the first expansion, like Nostalgia, the Protoss player will not be able to make the large amount of Vespene Gas intensive units that are so crucial. The Shield Battery may significantly extend the lives of units such as Archons, Reavers, High Templars, and Dragoons. On island maps, where Vespene Gas is also limited due to the difficulty in obtaining expansions and where air units and dropping is more common, Shield Batteries become more viable as well.
A Dragoon or two with a Shield Battery can be used in combination with Micro to great effect against many Marines. The Protoss player may need several Shield Batteries to recharge a large number of the Carriers.
In defensive PvZ situations, Shield Batteries can be used with a Reaver to hold off an all-in opponent attack. Corsairs can also benefit from the Shield Battery recharge.
In all Protoss match-ups, the Protoss can benefit from having a Shield Battery in aiding the Protoss player's Shuttle/Reaver harass, as Shuttles or Reavers low on Shields can be recharged. After a Fast Expansion, the Protoss player may benefit from a Shield Battery while being behind on numbers of units. This come in very handy when executing a Nexus before Gateway, as described in Frozen's PvP FE guide .
The Protoss player may opt for getting a Shield Battery in 2v2 when a Zerg ally won't need the detection Photon Cannons offer. In fact, Shield Batteries are more viable in 2v2 games. The Protoss player may need to hold the choke point or ramp for as long as possible while the player's ally's slow Marines or non-speed upgraded Zealots come to provide defensive help.
A Shield Battery can be used in conjunction with just about any other unit. Although it requires more clicking actions, they can help the Protoss player to fortify a defended location. Although they might not be as valuable in 1v1 as in a 2v2, the Shield Battery can be instrumental in defending both teammates, especially with replenishing nearby Archons. Archons and a Shield Battery are particularly effective against masses of Zerglings. During a Fast Expand, the Protoss player may want to warp another Shield Battery at the Expansion so as not needing to retreat back to the original Shield Battery. Also, a Shield Battery can be placed near the mineral line for Archons defending against potential Mutalisks.
Methods to use the Shield Battery
There are three methods to using the Shield Battery:
- It can be placed in an unobstructed area near the Protoss player's units to recharge multiple units at a time
- It can be used on individual units
- The Protoss player can select the desired units and then right-click on the Shield Battery.
Note whenever the Shield Battery is used to recharge units, all units targeted will have to stop attacking while being recharged. This may be challenging when being attacked at the choke point or ramp. An alternative is to only target the weakest or most damaged units. Perhaps the most effective method is pulling the wounded units out of the line to the rear to recharge before later regrouping. One should note using the Shield Battery on a unit results in it losing its hold position. As such, Zealots can be lured away by Zerglings.
Shield Batteries may obstruct unit flow if placed improperly. When using the Shield Battery, there exists the disadvantage of having to bring the unit away from the battle to recharge at the Shield Battery. One exception to this is the Reaver, which has such a long cool-down that it makes little difference.
As a defensive structure, Shield Batteries aren't effective when used with units that are taking heavy damage. In the amount of time the unit spends not attacking and recharging, it may lose more than the Shield that is recharged. This is one reason why Shield Batteries generally become less useful later in the game. In the late game it may not be worth it to recharge units when the Protoss player requires too many Shield points to recharge and cannot take them out of combat for a moment to recharge. Also, it may be inefficient to use the Shield Battery because of the long time necessary for its own recharge.
- Tempest uses a Shield Battery against Light's proxy Barracks
- JangBi uses a Shield Battery to attack while Horang2 uses Shield Batteries to defend
- Shuttle defends with a Shield Battery against EffOrt's 6 Pool