Low - cost, easily fabricated dry cells were constructed by gluing a composite conducting material or a metal sulphide on magnesium or aluminium foils, using a solid electrolyte made from polyvinyl - pyrolidone. Composite conducting materials consisted of polypyrrole and polyaniline incorporated into an inorganic or polymer matrix or cupric oxide incorporated into a styrene - butadiene copolymer matrix. The efficiency, energy densities and voltage values of the cells were in the range 0.5 – 18.3 mWh cm−3, 9 – 339 wh kg−1 and 0.5 – 2.0 V, respectively. The energy densities of the cells were up to seventeen times more than the energy density of the PbO2 -H2SO4 - Pb multiple charge / discharge system and up to ten times more than the energy density of the nickel / cadmium rechargeable cell. A dry cell composed solely from polymers was constructed with cell voltage 0.25 – 0.50 V and efficiency ranging from 0.07 to 0.13 mWh cm−3 ten times lower than other commercial cells.