In making batteries you could use copper and zinc in an acid electrolyte.     
Copper=copper wire (pennies are now mostly zinc if I recall correctly)
zinc= zinc strip (Hardware stores arround here (Seattle) sell this to prevent
      moss buildup on the roof. An alternative would be to use a galvanized
      (zinc coated) nail
electrolyte= lemon juice -> Citric acid is the active ingrediant(sp).
 
Volta (late 18th century scientist) used a stack for his batteries-
copper disk, paper disk soaked in acid, zinc disk, copper disk, paper ....
they were advanced technology for the time. 