1, the safety valve opening pressure is too high, or the safety valve is blocked. When the internal pressure increases to a certain degree when the valve can not open normally, in this case is bound to cause bulging deformation.
2. The floating charging voltage is set too high, the charging current is large, leading to the acceleration of O2 precipitation on the positive plate, and too late to compound in the negative electrode. At the same time, the temperature of the battery body rises quickly, and when the exhaust is not as good as the pressure reaches a certain point, the VRLA battery appears bulge deformation.
3, VRLA battery charging operation, especially in series battery pack, if the battery pack has been charged, if there is bad quality of the battery often appear bad internal gas compound phenomenon, so as to appear bulge phenomenon.
4, because VRLA battery belongs to the poor liquid type design, the combination of gas has reserved avoidance, and if there is a "rich liquid" phenomenon, it will prevent the diffusion of O2 to the negative electrode, reduce the O2 compound rate, the body pressure increases.
