The utility model discloses a lever is automatic spacingly prevents that short circuit adds liquid device for battery, it mends filling opening and gas vent to be equipped with respectively on the fluid infusion exhaust combined cover, the below of mending the filling opening is equipped with and extends to battery case inside and have the feed liquor pipe that the short circuit function is prevented in gas storage, the inboard upper portion of mending the filling opening is equipped with the cavity obturating cup, the inside of mending the filling opening is equipped with the sealed nail with cavity obturating cup adaptation, the bottom of sealed nail and the one end fixed connection of reinforcement lever, the fluid infusion exhaust combined cover lower part of neighbouring feed liquor pipe is equipped with suspends branch in midair, the other end and the keg float fixed connection of reinforcement lever, keg float floats in liquid, the reinforcement lever articulates through the round pin axle and be used for realizing the reinforcement effect on suspending branch in midair. The utility model discloses swift, the low -cost few safe and reliable that maintains and use of convenient operation.