Long life lead acid battery having titanium core grids and method of their production

A deep discharge lead-acid battery comprising a case, a plurality of cells in the case and a plurality of positive and negative interleaved battery grids with separators therebetween within each cell;

• (a) at least some of said positive grids having titanium cores;
• (b) said titanium cores each having an expanded metal body portion and being a titanium alloy containing from 0.01 to 0.9% of a platinum group metal;
• (c) said titanium cores each having a flash coating of 0.5 to 10 microns of silver;
• (d) said titanium cores each having a lead coating over the silver coating, which is a hot melt lead coating and not an electroplated coating;
• (e) said titanium core grids having a thickness, including the lead coating, of more than 0.5 mm and less than 2.0 mm.

A method of making a lead-acid battery having a plurality of composite positive battery grids, said grids having a thin titanium core of less than 2.0 mm thickness, which core has front and back faces;

• said core having a body portion of expanded titanium, an unexpanded bar portion at the top of the body portion, a lug connected to the bar portion, the top bar portion having two opposed wing portions which extend beyond the body portion, the opposed sides of the body portion being expanded (not unexpanded bars);
• the method including the steps, in sequence, of:
• (a) expanding a coil of titanium having a thickness of less than 2.0 mm to form a web comprising a series of joined grids, the grids being connected by the wing portions of the grids;
• (b) progressing the web through cleaning tanks and through at least one electroplating tank and electrocoating the titanium grids with a flash coating 1-20 microns thick selected from the group of silver and nickel;
• (c) cutting the web into individual grids by severing the wing portions;
• and
• (d) forming the grids into a lead-acid battery having negative grids and with separators between each negative and positive grid.