A device for electrolyzing water, the device comprising: an electrolysis unit, comprising: a chamber; an ion exchange structure in the chamber, the ion exchange structure comprising: an ion exchange member that is configured to separate the chamber into a first compartment and a second compartment; a cathode disposed on a first portion of the ion exchange member and that is located in the first compartment; and an anode disposed on a second, different portion of the ion exchange member and that is located in the second compartment; the device further comprising: a case (22, 68) enclosing the electrolysis unit and a high pressure chamber that receives hydrogen gas that results from the electrolysis of water in the ion exchange structure; and a reservoir housing enclosing a collapsible reservoir, that comprises a spring loaded bladder, the reservoir housing disposed within the high pressure chamber, the reservoir housing having: at least one channel that provides fluid communication between an interior portion of the collapsible reservoir and the second compartment of the chamber of the electrolysis unit; and at least one port that provides fluid communication between the outer surface of the collapsible reservoir and the high pressure chamber, the reservoir configured to store water and to supply stored water to the chamber of the electrolysis unit. an electrolysis unit, comprising: a chamber; an ion exchange structure in the chamber, the ion exchange structure comprising: an ion exchange member that is configured to separate the chamber into a first compartment and a second compartment; a cathode disposed on a first portion of the ion exchange member and that is located in the first compartment; and an anode disposed on a second, different portion of the ion exchange member and that is located in the second compartment; a chamber; an ion exchange structure in the chamber, the ion exchange structure comprising: an ion exchange member that is configured to separate the chamber into a first compartment and a second compartment; a cathode disposed on a first portion of the ion exchange member and that is located in the first compartment; and an anode disposed on a second, different portion of the ion exchange member and that is located in the second compartment; an ion exchange member that is configured to separate the chamber into a first compartment and a second compartment; a cathode disposed on a first portion of the ion exchange member and that is located in the first compartment; and an anode disposed on a second, different portion of the ion exchange member and that is located in the second compartment; the device further comprising: a case (22, 68) enclosing the electrolysis unit and a high pressure chamber that receives hydrogen gas that results from the electrolysis of water in the ion exchange structure; and a reservoir housing enclosing a collapsible reservoir, that comprises a spring loaded bladder, the reservoir housing disposed within the high pressure chamber, the reservoir housing having: at least one channel that provides fluid communication between an interior portion of the collapsible reservoir and the second compartment of the chamber of the electrolysis unit; and at least one port that provides fluid communication between the outer surface of the collapsible reservoir and the high pressure chamber, the reservoir configured to store water and to supply stored water to the chamber of the electrolysis unit. a case (22, 68) enclosing the electrolysis unit and a high pressure chamber that receives hydrogen gas that results from the electrolysis of water in the ion exchange structure; and a reservoir housing enclosing a collapsible reservoir, that comprises a spring loaded bladder, the reservoir housing disposed within the high pressure chamber, the reservoir housing having: at least one channel that provides fluid communication between an interior portion of the collapsible reservoir and the second compartment of the chamber of the electrolysis unit; and at least one port that provides fluid communication between the outer surface of the collapsible reservoir and the high pressure chamber, the reservoir configured to store water and to supply stored water to the chamber of the electrolysis unit.