Patent ID: 7074511

Claim:
A liquid feed fuel cell system comprising: (A) a direct oxidation fuel cell including a membrane electrode assembly; (B) a source of fuel; and (C) a fuel container coupled with said fuel source and including: (i) an inner flexible bladder that is substantially fully expanded upon being filled with fuel from said fuel source, and having a conduit that is coupled to said membrane electrode assembly to supply fuel to said membrane electrode assembly; (ii) a force applying instrument that acts upon said bladder to compress the bladder such that the fuel contained in said bladder is expressed through said conduit towards said membrane electrode assembly; and (iii) a fuel gauge including a transparent window in said container, and a visual indicator integrated into said container, and a calibration scale on an outer wall of said container, in such a manner that as said flexible bladder moves towards said conduit when fuel is consumed from said bladder, a visual indication of fuel volume is provided.