A fuel cell stack is the part of a fuel cell that makes the electricity: a pile of thin cells connected in series. One cell gives less than one volt under load, so many cells are stacked to reach a useful voltage and power.
Stack or complete system?
A stack alone does not run. A complete system adds the hydrogen supply, the air supply, the control electronics and often a battery for load peaks. Buy a stack if you design the system yourself. Buy a system if you want a power unit that is ready to connect.
Can you recharge a fuel cell?
No. You refuel it with hydrogen, which takes about two minutes.
Figures from the Unconventional Energy product pages. Updated 2 November 2026.