Enclosed lead storage battery and process for producing the same

An enclosed lead storage battery comprising a plate assembly consisting of a positive plate, negative plates and a separator, pole posts connected to said positive plate and said negative plates, respectively, an electrolyte held in position by said plate assembly, and a jacket made of film- or sheet-formed synthetic resin wherein:

• (a) each pole post is provided with a layer of polyolefin resin around at least a portion of each post, said layers of polyolefin being adhered to said posts by a layer of epoxy resin;
• (b) the jacket comprises a laminate film or sheet comprising a polyolefin film on the inside contacting the plate assembly and a film comprising at least two layers of thermoplastic synthetic resin on the outside thereof;
• (c) the jacket is heat sealed at its periphery surrounding the plate assembly, excepting a portion which serves as a safety valve and which is left in a film-to-film adhering state;
• and
• (d) the jacket is also heat sealed to the layers of polyolefin resin adhered to the pole posts.