A method of packaging a battery device with a metal shell, comprising: applying a waterborne two-component polyurethane composition to the metal shell of the battery device, and drying the applied polyurethane composition to form a packaging layer; wherein the polyurethane composition comprises, (A) an aqueous dispersion comprising a hydroxyl-functional polymer, wherein the hydroxyl-functional polymer comprises, by weight based on the weight of the hydroxyl-functional polymer, from 20% to 50% of structural units of a hydroxy-functional alkyl (meth)acrylate; from 0.1% to 10% of structural units of an acid monomer, a salt thereof, or mixtures thereof; and structural units of a monoethylenically unsaturated nonionic monomer; and (B) a polyisocyanate.