Power cell

A power cell was a type of energy source.

Cybermen
The second variant of Cyber-body used by the Cybermen of the Cyber Legions during the Cyber Wars of the 250th Millennium, (TV: Nightmare in Silver, PROSE: Ghost in the Machine) as well as numerous identical Cybermen across N-Space (TV: Dark Water, Death in Heaven et al.) and a parallel universe, (AUDIO: Code Silver) featured blue power cells, instead of the Cyber-chest packs and chest units used by previous Cyberman evolutions, (TV: The Tenth Planet et al.) or the chest plates used by the Cybusmen. (TV: Rise of the Cybermen, The Age of Steel, A Good Man Goes to War) Such power cells also appeared on the patchwork Cyber-suit of Ashad, (TV: The Haunting of Villa Diodati) the Lone Cyberman who operated in the aftermath of the far future Cyber-Wars, as well as those of the Cyber-Warriors and, (TV: Ascension of the Cybermen) by extension, the CyberMasters. (TV: The Timeless Children)

Other
Upon learning that the Cult of Skaro escaped the Battle of Canary Wharf by emergency temporal shift, the Tenth Doctor gloated that the four Daleks must have "roasted" their power cells. (TV: Evolution of the Daleks)

TARDISes contained TARDIS power cells. (TV: Rise of the Cybermen)

Phason pods were a type of compressed power cells. (AUDIO: Daughter of the Gods)