By doing the Call to Arms quest, it is possible to potentially get an infinite amount of fusion cells.With patch 1.4, fusion cells can be found with the Scrounger perk.Three at the entrance of the Museum of Freedom in Concord, by a dead Minuteman and a laser musket.Eight near the Fort Hagen filling station.Eight outside, and seven inside the Castle.Eight inside the University Credit Union.10 in the Synth Retention division of the Institute.12 cells in the Advanced Systems division of the Institute.Gunners, Brotherhood of Steel members, Minutemen, and Institute synths often carry laser weapons as well as fusion cells.Merchants usually sell this ammunition type.
* Requires fusion magazine mod Locations A fusion cell nearly resembles an electric battery with positive and negative symbols, directional arrows, and a warning label on the side saying 'WARNING WILL EXPLODE IF DISPOSED OF IN FIRE.' Fusion cells are typically used by laser-based energy weapons.