VRLA(Valve regulated lead acid) batteries which were improved form typical flooded type, have been common in relative batteries industry. VRLA batteries are an enabling technology for a variety industries, particularly telecommunication, information technology, portable device, electric vehicle, a power generation system and etc. VRLA batteries have two type as AGM and gel. The gel type VRLA battery technology is not common in the interior of a country. On the technology of gel type VRLA bateries manufacture, we had a study about the characteristic of gel electrolyte and the effect of gel electrolyte when applied to the batteries as function of silica wt%. The gel electrolyte which is mixture of silica, water, diluted sulfuric acid and etc. The gravity of used diluted sulfuric acid is 1.265g/ml at 25 ℃ and silica is pyrogenic silica. Three kind of gel electrolyte were made and each of them contains 5wt%, 7wt% and 8wt% silica. The gravity, pH, viscosity and gelling time of the gel electrolyte were tested and applied to batteries. The batteries have been cycle-life test under the DOD100% with the C5/5 at 25 ℃. The cycle-life tests of these batteries are going on.