Ok, Now I did this test:
Filled up my cell with water, then removed exactly one liter of water, so that gives me the one liter cavity.
Ran the cell for one minute, 12 volts at 15 AMPS.
It build up 15PSI of pressure.
the 15 PSI of pressure was only able to fill a one litter bottle with HHO.
If don't beliave me, do the test your self. it is very easy.