TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Method: In method (II): the step (a) comprises allowing fuel to flow out from a fuel chamber so that a volume of the fuel chamber decreases by an amount, or a first side of the fuel chamber moves a distance towards a second side, and step (b) comprises allowing a by-product of a reaction between the fuel and a reactant to flow into the reaction-byproduct chamber so that a volume of the reaction-by-product chamber increases by an amount, or a first side of the reaction-by-product chamber moves away a distance from a second side, or the steps (a) and (b) comprise allowing the fuel and by-product to flow so that a partition between the fuel and reaction-by-product chambers moves toward a side of the fuel chamber and away from a side of the reaction-by-product chamber. The method (II) further comprises generating electricity with the reaction-by-product. In method (II), the step (c) comprises decreasing the volume of the fuel chamber, and step (d) comprises increasing the volume of the fuel reaction-by-product chamber, or the steps (c) and (d) comprise moving a partition between the fuel and fuel reaction-by-product chambers.    TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The device further comprises: a fluidic conduit in flow communication between the reaction chamber and the second storage chamber; and a microfluidic unit interposed between the first storage chamber and the reaction chamber, where a separation wall (28) has a position that corresponds to the level of the reactant in the first storage chamber, and the separation wall is self adjustable with the activation of the microfluidic unit. The tank chamber is a hollow cylindrical body closed by a first end wall and by a second end wall, where the removable partition means is the separation wall slidingly guided between the first end wall and the second end wall. The fluidic conduit is arranged internally and axially to the tank chamber with the separation wall that is associated with the fluidic conduit smoothly, where the first storage chamber is interposed between the reaction chamber and the second storage chamber. The second end wall of the tank chamber comprises a gas/liquid separator (31). The reaction chamber is a hollow cylindrical body, co-axial to the tank chamber, comprising a bottom wall and a cover, where the cover comprises many holes realized on the surface and arranged inside a peripheral curb, and defines with the first end wall a diffusion chamber for the gaseous hydrogen. In the apparatus: the tank is cylindrical, and comprises an end wall adjacent to the fuel chamber, and a conduit (which is cylindrical) extending from the end wall, through the fuel chamber and the divider, and into the reaction-by-product chamber; the divider comprises a center, and the tank comprises the end wall adjacent to the fuel chamber and having a center, where the cylindrical conduit extends from the center of the end wall, through the fuel chamber and the center of the divider, and into the reaction-by-product chamber; or the tank comprises a side wall, and the divider comprises an edge that is operable to form a liquid (fluid)-tight seal with the side wall. The divider is disc shaped. The apparatus further comprises: spacers secured to the divider and extending into the reaction-byproduct-chamber, and a separator disposed adjacent to an end of the tank so that the reaction-by-product chamber is disposed between the separator and the divider, where the separator is permeable to a gas and impermeable to a liquid; a gas diffuser disposed adjacent to an end of the tank so that the reaction-by-product chamber is disposed between the diffuser and the divider; a fuel cell operable to convert the reaction-by-product from the reaction-byproduct chamber into electric power; a fuel cell disposed adjacent to the reaction by-product chamber and operable to convert hydrogen from the reaction-by-product chamber into electric power; a fuel cell operable to convert the reaction-by-product from the reaction-by-product chamber into an input voltage, and a regulator operable to generate a regulated output voltage from the input voltage; a reaction chamber; a reaction chamber disposed adjacent to the fuel chamber and including the reactant; a reaction chamber, and a pump operable to transfer fuel from the fuel chamber to the reaction chamber; the reaction chamber, and a pump disposed outside of the tank and operable to transfer fuel from the fuel chamber into the reaction chamber; or a reaction chamber in communication with the reaction-by-product chamber, a pump operable to transfer fuel from the fuel chamber to the reaction chamber at a transfer rate, a fuel cell operable to convert the reaction-by-product from the reaction-by-product chamber into an input voltage, and the regulator to generate regulated output voltage from the input voltage by controlling the transfer rate of the pump. In the system, the fuel cell is operable to convert the reaction-by-product into a voltage. The second apparatus comprises: an integrated circuit; a phone; a computer; a universal serial bus capable apparatus; or a portable electronic apparatus. The fuel chamber is located above or below the reaction-by-product chamber.