Dalek Battlecruisers were a large part of the Dalek Empire's fleet.
History
Hundreds of battlecruisers faced Movellan Battlecruisers during the Daleks' war with the Movellans due to a stalemate that had been reached when neither side could compute a winning strategy. (TV: Destiny of the Daleks)
When Davros, the creator of the Daleks, was being held aboard a prison space station, the Daleks used one of their battlecruisers to attack the station and retrieve him. (TV: Resurrection of the Daleks) This was a "supercharged class 6" battlecruiser, equipped with Grade-A Terror Weapons and treble reinforced shields. It was known in to the militaries of other species as the "Ball Crusher." (PROSE: Resurrection of the Daleks)
[[Renegade Dalek|Daleks loyal to the Supreme Dalek manned a Mark Seven Statin shuttle from a Dalek freighter to the planet Necros, where Davros was found and captured. (PROSE: Revelation of the Daleks, TV: Revelation of the Daleks) According to the Time Lords' Dalek Combat Training Manual, the ship which landed on Necros was infact a class of Dalek Battlecruiser. (PROSE: Dalek Combat Training Manual)
Dalek battle cruisers used by the Daleks loyal to the Emperor Dalek were saucer-shaped like their shuttles. (COMIC: Emperor of the Daleks!)
Battlecruisers were among the Dalek fleet that fought in the Last Great Time War. The Time Lords planned to unleash a genetically engineered breed of Dalekanium-eating Vashta Nerada against them but were forced to abandon the project following an incident on Synthesis Station. (AUDIO: Day of the Vashta Nerada)
Some Dalek saucers were also classed as battle cruisers; the Eleventh Doctor initially took Ship Sigma to be a battle cruiser before learning it was a survey ship. (COMIC: The Dalek Project)