Lead-Acid Gel batteries are used in back-up power supplies for alarm and smaller computer systems (particularly in uninterruptible power supplies) and for electric scooters, electrified bicycles, transportation and marine applications. Unlike wet cells, gel cells are sealed, with pressure relief valves in case of overcharging. During normal use they cannot spill liquid electrolyte.
In the production of lead acid gel batteries for automobile and transportation sectors, gases such as H2 and O2 can be emitted. The emission of these gases by such batteries when charging or discharging can be controlled by sealing the top battery with an electrical resistant foil or film. For example, PIT5N (Polyimide) exhibits a high breakdown voltage, depending upon the film thickness. This material can be used to seal the valves, which would not protect the emission but would lower the rate of battery detonation, due to delocalized electrostatic discharge by the Polyimide film.
For each battery, a thin strip of film or tape is required to reduce these charges. These films are required for specific battery applications, where vicinity charges are higher.