NOVELTY - The charge indicator responds to deformation such as change in physical dimensions of solid component comprising mixture of metal hydride powder and composite hydrogen storage material in contact with fluid such as hydrogen. The deformation is a function of the mass of fluid contained within the fluid enclosure (1000).    USE - Charge indicator for fuel cell system (claimed) used in cellular phone, satellite phone, personal digital assistant (PDA), laptop computer, computer accessory, ultra mobile computer, display, personal audio or video player, medical device, television, transmitter, receiver, lighting device, flashlight or electronic toy (all claimed).    ADVANTAGE - By responding to a deformation, the state of charge indicator relies on an effect directly related to the state of charge of the fluid enclosure and not on any secondary effects such as environmental temperature, fluid storage material settling, environmental barometric pressure, environmental humidity, and aging of fluid storage material.    DETAILED DESCRIPTION - The environmental temperature changes, environmental humidity changes, environmental barometric pressure changes introduce less than about a 1% error in determining the mass of fluid contained within the fluid enclosure. The deformation comprises about 3-10% deformation. The charge indicator comprises mechanical transducer, open cell foam, lever indicator, and a visible window to view the deformation of the component. The window is at 90 degrees angle to the component. An optical interference pattern comprising pixels provides visible words upon straining the component. INDEPENDENT CLAIMS are included for the following:    (1) fuel cell system which comprises solid components in contact with the fluid enclosure, and charge indicator in contact with solid components and fluid enclosure. One or more fuel cells are in contact with the solid components, charge indicator and fluid enclosure. The fluid enclosure system comprises a volume of less than about 1000 cubic centimeters; and    (2) method for determining the mass of fluid contained within a fluid enclosure involves responding to a deformation of a solid component by displacing a solid, liquid or resisting an electrical signal. The deformation is a function of the mass of a fluid contained within the fluid enclosure. The mass of fluid in contact with a fluid enclosure is displayed.    DESCRIPTION OF DRAWING(S) - The drawing shows the schematic view of the state of the charge indicator system.    Fluid enclosure (1000)    Smaller fluid enclosure (1002)    Larger fluid enclosure (1004)    Connection (1006)    Fluid inlet/outlet (1008)