On Colonial warships, a battery is a group of large gun turrets working together. A battery may consist of any number of gun turrets and the arrangement varies from class to class.
Colonial-class battlestars are armed with 24 gun turrets, with two gun barrels each. Eight are mounted on the dorsal and twelve on the ventral hull. Of these twelve, eight are mounted on the bow and are thus able to fire directly forwards. It is likely that the term "battery" refers to several of these turrets acting in concert.
On Mercury-class battlestars, on the other hand, four forward guns are grouped to a battery. In addition, many smaller, 2-barrelled turrets are located along the sides of the flight pods. Unlike rapid-fire point defense guns, these have a slower rate of fire and are also used for offensive action.
- In modern day naval nomenclature, a vessel's "main battery" is its primary offensive weapon. Since the battery of four two-barrelled gun turrets at the bow of a Mercury Battlestar has been referred to as such on several occasions, it is likely that this battery - presenting the battlestar's smallest profile to the enemy - is used primarily for offensive actions, while the others could be adapted for use as per mission parameters.
The large turrets found on Colonial battlestars fire several types of ammunition, depending on the objective:
- Flak ammunition: this ammunition employs exploding metal fragments at high velocity, creating a defensive barrier around the battlestar which can shear enemy fighters or incoming missiles. This, along with the point-defenses, keep the enemy at a distance, allowing the battlestar's Viper forces to safely deploy and engage.
- Offensive ammunition: in this configuration, salvos from the main cannons are extremely lethal to the unarmoured Cylon basestars, which furthermore possess no such weapons or point-defence themselves. As such, this is a battlestar's main weapon against other capital ships.
It should be noted that the massive recoil caused by firing these flak rounds makes it impossible for the cannon to have a fast rate of fire like the battlestar's point-defence turrets. These shells are also too large to be loaded quickly and efficiently by crew members, and as such are loaded by mechanical hoists.
When engaging enemy targets over any kind of distance, a firing solution must be obtained. This requires several pieces of information to be input to a battery's fire-control computer, including the target's speed, course, and range; and the firing platform's speed and course. The velocity of the shells would be known, and is constant, given that there is no air friction in the vacuum of space. The resulting computation would allow the gun captains to accurately aim their weaponry to such a degree that firing will result in a probable hit.
Colonial gun batteries have several modes of operation.
- Salvo Fire: this calls for a battery, or elements of a battery, to fire simultaneously at a single target.
- Full Attack Mode: a battery's commander, called gun captain, will target and engage targets of opportunity.
On Mercury-class battlestars, gun batteries can be set to one of several automatic firing modes. It is unknown if the gun batteries on older battlestars have this capability as well.
At least on Colonial-type battlestars, the turrets appear to be manned and manually fired.