NOVELTY - A crystalline silicon battery back plate adhesive contains component A containing 40-60 pts. wt. hydroxyl- or carboxyl-containing resin, 5-10 pts. wt. chain extender, 3-5 pts. wt. hydrolysis stabilizer, 0.05-3 pts. wt. antioxidant, 0.01-5 pts. wt. catalyst, 18-50 pts. wt. diluent 1, and component B containing 30-50 pts. wt. etherified polymethylol melamine resin and 50-70 pts. wt. diluent 2 in which hydroxyl- or carboxyl-containing resin is alkyd resin, polyester resin, acrylic resin, and/or epoxy resin, and chain extender is ethylene glycol, 1,2-propanediol, and/or 1,4-butanediol.    USE - A crystalline silicon battery back plate adhesive used for bonding polyethylene terephthalate (PET) film with PET film, polyvinyl fluoride (PVF) film, polyvinylidene difluoride (PVDF) film, or polyethylene (PE) film (all claimed).    ADVANTAGE - Crystalline silicon battery back plate adhesive has high interfacial bonding strength for 2 PET films and other materials, and good thermal oxidative aging resistance and water resistance.    DETAILED DESCRIPTION - A crystalline silicon battery back plate adhesive contains component A containing 40-60 pts. wt. hydroxyl- or carboxyl-containing resin, 5-10 pts. wt. chain extender, 3-5 pts. wt. hydrolysis stabilizer, 0.05-3 pts. wt. antioxidant, 0.01-5 pts. wt. catalyst, 18-50 pts. wt. diluent 1, and component B containing 30-50 pts. wt. etherified polymethylol melamine resin and 50-70 pts. wt. diluent 2 in which hydroxyl- or carboxyl-containing resin is alkyd resin, polyester resin, acrylic resin, and/or epoxy resin, chain extender is ethylene glycol, 1,2-propanediol, 1,4-butanediol, neopentyl glycol, diethylene glycol, glycerin, trimethylolpropane, trimethylolethane, and/or polyethylene glycol, hydrolysis stabilizer is monomeric carbodiimides hydrolysis stabilizers, polycarbodiimide hydrolysis stabilizer, and/or monocarboxylic acid glycidyl methacrylate hydrolysis stabilizer, antioxidant is 2,2'-methylene-bis-(4-methyl-6-tert.-butyl)phenol, 2,2'-methylene-bis-(4-ethyl-6-tert.-butyl)phenol, 1,3,5-tris(4-tert.-butyl-3-hydroxy-2,6-dimethyl benzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 3,5-di-tert.-butyl-4-hydroxy-benzoic acid hexadecyl ester, distearyl pentaerythritol diphosphite, tris(2,4-di-tert.-butylphenyl) phosphite ester, and/or tris (1,2,2,6,6-pentamethyl-4-4 piperidyl) phosphite ester, catalyst is p-toluenesulfonic acid, phthalic acid, isooctanoic acid, lauric acid, and/or acetic acid, diluent 1 and diluent 2 are ketone, aromatic hydrocarbon, oil, alcohol, and/or ether solvent, and etherified polymethylol melamine resin is methyl etherified hexamethylol melamine resin, butyl etherified hexamethylol melamine resin, and/or mixed etherified hexamethylol melamine resin. An INDEPENDENT CLAIM is included for application of crystalline silicon battery back plate adhesive for bonding polyethylene terephthalate (PET) film with PET film, polyvinyl fluoride (PVF) film, polyvinylidene difluoride (PVDF) film, or polyethylene (PE) film.