Lead acid cells and batteries

A sealed lead acid cell characterized in that it has electrodes comprising metallic supports which minimize the evolution of hydrogen and resist deformation under their own weight, the supports for the electrodes being in the form of a mesh or grid affording an integral current collecting strip or bar along at least one edge which will be the top or bottom edge of the structure when assembled in a cell and the supports for the electrodes being made of a lead-calcium-tin alloy containing 0.04 to 0.08% by weight calcium and 0.1 to 0.5% tin, and which are separated by at least one layer of separator material, the support of the positive electrode or electrodes having positive active material deposited thereon, the deposited positive active material being formed from a positive active material paste composition consisting of from 23 to 57 parts by weight of liquids per 100 parts by weight of the lead content of the active material and from 0.01 to 1.0 parts by weight of silica calculated as SiO.sub.2 per 100 parts by weight of active material (calculated at PbO.sub.2) and the support of the negative electrode or electrodes having negative active material deposited thereon, the deposited negative active material being formed from a negative paste active material composition which includes at least 0.1% by weight of lignin derived lignosulphonate material, and in which the capacity of the negative electrodes is arranged to be at least as great as the capacity of the positive electrodes, the thickness of the electrodes is less than 3mm, the thickness of the separator is in the range of 10 to 200% of the thickness of the electrodes and the volume, E, of electrolyte in the cell in relation to the sum of the pore volume of the separators, X, and the pore volume of the positive and negative active materials, Y, is not greater than 2X + Y.