The plasmatic battery unit, better known as the power cell, is type of modular ammunition used in plasma-based directed energy weapons. Because of its convenient size and its ability to power most small arms for extended periods of time before requiring replacement, it is favored by the Federation and most militarized factions. One of its shortcomings is that it is not compatible with plasmaless phaser or disruptor-type weapons. The plasmatic battery unit could be considered a modern counterpart to the firearm magazines used by Humans in the 20th and 21st centuries.