Fuel Cell

The Fuel Cell in an unlockable Uncommon item in Risk of Rain 2. Each cell gives the player's activatable item(s) an additional charge and reduces the cooldown time by 15%.

The amount of time left for the item to gain an additional charge is not displayed anywhere, meaning it may be difficult to know how much time is left for a charge to be added.

Completing the "Experimenting" Challenge unlocks this item.

Notes:
"As humanity began to venture out into the depths of space, high-energy but low-volume fuel sources became critical for interplanetary travel. Stability came later."

-Brief History of Interplanetary Advances, Vol.2