Lead-Acid Battery: Jar-Cover Seals

The leakage of electrolyte from lead-acid storage batteries has been a chronic problem to consumers. Industrial and individual consumers share such common seal-related deficiencies as electrolyte leakage, corrosion buildup and premature battery failure. Additionally, telephone companies have experienced high maintenance costs, fire and explosion hazards, and interrupted service.1 These problems can be related to both the inherent characteristics of the lead-acid sj^stem and to inadequate joint design considerations. The limited availability of materials resistant to battery acid and the dimensional changes which occur in electrodes and plates are factors, inherent in lead-acid batteries, which result in poor reliability. Poorly designed cap or plug type jarcover seals on batteries currently used in telephone plant provide very little effective seal area. In addition, they all use adhesives or sealants with low toughness which further contributes to premature battery failure. These effects are more obvious in batteries for telephone use because of their large dimensions, type of service and long design life. Early in the development of the new cylindrical battery, studies were undertaken to provide reliable jar-cover seals. The initial performance requirements for the seal were that: 1393