Upgrades
Upgrades add on to Equipment to give them bonuses or new features. They require maintenance at the same time as the Equipment, adding extra Maintenance Kits to the total.
Upgrades frequently require Power Cells to use their effect. These are a Resource that should be attached to the piece of equipment they are powering, and are ripped when that item uses its powered effect. This is how we limit how frequently an effect can be used (many other games use per-encounter or daily use limits).