A miniature electrochemical cell of a primary or a secondary chemistry with a total volume that is less than 0.5 cc is described. The cell has a casing comprising an annular sidewall supported on a lower plate opposite an upper closure plate. The upper plate has a sealed electrolyte fill port. A current collector having an opening aligned with the fill port contacts an inner surface of the upper plate. An anode active material contacts the lower plate, and a cathode active material contacts the upper closure plate. A dielectric material coats the lower open end of the annular sidewall and a portion of the inner surface of the sidewall. A glass seals the dielectric material to the lower plate. An electrolyte contacts the electrode assembly. The cathode active material contacting the current collector has an opening aligned with the current collector opening and the electrolyte fill port.