Filling mat-immobilized-electrolyte batteries

In a method of assembling a mat-immobilized-electrolyte Pb-acid storage battery comprising the principle steps of assembling a galvanic cell element containing compressible, absorbent mats sandwiched between positive and negative polarity electrodes, compressing said element so as to compress said mats, inserting at least one said compressed element into a container, and impregnating said element with said electrolyte while in said container, the improvement comprising:

• positioning a cover on said container, said cover having a first and second opening therein overlying each of said battery's elements, said first opening lying near one side of said battery on one side of a centerline of said battery and said second opening lying near another side of said battery opposite said one side and on the opposite side of said centerline;
• laying said battery on said one side such that said second opening is above said first opening;
• introducing electrolyte into said container through said first opening;
• allowing said electrolyte to capillarily rise throughout said element so as to wet substantially the entire internal surface of said mats at substantially the wicking rate of said electrolyte in said mat, but without completely saturating said element;
• displacing any gases in said container with said rising electrolyte and venting them from said container through said second opening;
• placing said battery in an upright position such that said openings overlie said element;
• adding additional electrolyte to said battery sufficient to insure substantially complete wetting of said electrodes;
• and
• covering said openings.