Assembly of sealed electrical cells within a ceramic housing having an opening at each end is carried out by assembling the components of the cell (anode, electrolyte, cathode) in the housing then securing an electrically conductive endplate to each open end using a fusible metal-contg. alloy solder. A layer of metal alloy solder is deposited on the peripheral area of each of the two conductive end sheets. The ceramic frame has an opening in the centre, and top and bottom surfaces on which at least one first layer of metal or metal alloy is deposited and secured (to provide a good ceramic to metal bond). The anode is in electrical contact with one terminal sheet and the cathode with the other.    The 1st. terminal sheet may be secured to the bottom surface of the frame prior to assembling the anode, solid electrolyte separator sheet and cathode in the opening of the frame or both sheets may be secured to the frame at the same time. The 1st. terminal sheet is pref. cooled during the securing of the 2nd. terminal sheet (e.g. with liq. N2). The sheets are pref. selected from Cu (more pref.), Ni and stainless steel. The solder is pref. a Sn/Pb solder. The terminal sheets are secured to the frame by soldering at 25-350 deg. C, 100-1200 psig for 3-25s. The frame and terminal sheets may have a circular, rectangular, square or polygonal configuration. One of the terminal sheets may have an extended tab that may be bent over onto the other terminal sheet and insulated from it so that both terminals can be on one side. The 1st. layer of metal or alloy deposited on the ceramic surface is selected from Cu, Ag, Au, Pt, Mo and their alloys. After assembly the cell is pref. encapsulated in an epoxy cpd.. The electrolyte is pref. a solid electrolyte separator which comprises poly(ethylene oxide), a metal salt, ethylene carbonate and propylene carbonate. The cathode contains active material selected from MnO2 (pref.) Fe and Cu sulphides, silver chromates, Pb. Bi, Cu and Ni oxides, carbon monofluoride, vanadium oxide, silver vanadium chromate and Cd. The anode is selected from Li (pref.), Li alloys, Ca, Na and K.    USE/ADVANTAGE -   The cell can be used to operate any electrical device designed to operate at the cell's output potential. It can be used in small battery devices. It can be encapsulated or moulded into various devices, printed circuit boards (to form a self-contained power electronic device in combination with other components) or electronic housings. A bipolar battery can be constructed from 2 cells placed one on top of the other to produce higher voltages. The cell has high temp. stability (up to 1300 deg. C., pref. 1700 deg. C). It will withstand flexural pressures up to 50 000, pref. 25 000 psi, compressive strength of 130 000 psi or higher, pref. 300 000 psi and tensile strength of 15 000 psi or higher, pref. 25 000 psi. It occupies a relatively small space.