Cross‐linking methods have been investigated to determine their effect on the performance of polyvinyl alcohol (PVA) films as alkaline battery separators. The following types of cross‐linked PVA films are discussed: (i) PVA‐dialdehyde blends post‐treated with an acid or acid periodate solution (two‐step method, and (ii) PVA‐dialdehyde blends cross‐linked during film formation (drying) by using a reagent with both aldehyde and acid functionality (one‐step method). Laboratory samples of each cross‐linked type of film were prepared and evaluated in standard separator screening tests. Then pilot‐plant batches of films were prepared and compared to measure differences due to the cross‐linking method. The pilot‐plant materials were then tested in nickel oxide‐zinc cells to compare the two methods with respect to performance characteristics and cycle life. Cell test results are compared with those from tests with Celgard.