flexure is the result of the force of atmospheric pressure acting on the walls of container 40 it will be readily appreciated that a force will be exerted on the exterior of the container walls when the pressure inside the cell 10 drops below atmospheric pressure the inward displacement of the walls 42 forces any excess electrolyte to rise inside the cell so that the liquid level 15 remains at approximately the lower end of vacuum tube 52 at least some of the displaced electrolyte removed by vacuum tube 52 is squeezed out of the agm separator material 34 between the plates thus as the walls 42 of the container 40 are drawn inwardly the electrolyte liquid level 15 remains near the lower end of vacuum tube 52 even as the amount of liquid electrolyte in the container 40 decreases desirably the vacuum application continues until the flexure created force generated by the container walls 42 pushes the excess electrolyte from the cell 10 too much flexure created force will leave the fibrous mat separators 34 in too dry a condition for proper recombination too little flexure created force will leave the fibrous mat separators 34 too saturated for the creation of the required gas passages therein in this latter situation additional time or other steps will have to be taken to remove additional electrolyte from the cell there is an optimum vacuum level that creates the proper amount of wall flexure and thus removal of.