Abstract: A method and device for filling a container with liquid up to a predetermined level. The device includes a cylinder and a piston movable within the cylinder between a rest position and a fill position. A supply of liquid for filling the container is provided to a first end of the piston at alternating pressures to cycle the piston back and forth between the rest and fill positions. Each time the piston reaches its fill position, supply liquid is added to the container. With each cycle the device draws fluid from the container and then attempts to compress the drawn fluid with a second end of the piston. When the fluid drawn is gas, the piston can compress the gas to continue moving to the fill position. When the drawn fluid is liquid, the piston can not compress the liquid and thus is stopped to prevent further filling.

Abstract: A vent plug for insertion into a battery vent well that retains the original large diameter of the well. The vent plug has a body having a top and a bottom and an opening extending from the top to the bottom. A neck extends from the body for insertion into the well. The neck has an opening therein and an arm positioned to engage the underside of a projection in the well without substantially intruding into the well diameter.

Abstract: An electrolyte level monitor used in combination with a battery having multiple cells. The monitor includes a circuit having an indicator which operates when the electrolyte level is at or above the minimum acceptable electrolyte level. The circuit is connected across cells of the battery to provide a potential to operate the monitor.

Abstract: The present invention provides method and apparatus for the automatic recirculation of battery electrolyte from industrial and similar batteries. The invention employs a vacuum system to remove electrolyte from a cell of the battery, transfer it to a central location where it can be treated, and then return it to the battery for its continued use. The invention lends itself to many forms of electrolyte treatment, including temperature adjustment, filtering, and removal of excess gases. The invention may be readily employed on virtually all industrial batteries with minimal modification and effort, and it greatly decreases maintenance time and expense for such batteries while increasing their flexibility and uses.

Abstract: An automatic shutoff device of the type which makes use of a venturi to terminate the flow of a liquid into a container when the liquid in the container reaches the level of the discharge tube. A movable housing is operatively positioned downstream of a constrictive nozzle giving rise to the venturi and a consequent low pressure area; the movable housing substantially encompasses the low pressure area except that the downstream end of the housing is open and may serve as a discharge tube from which liquid flows into the container to be filled, the filling operation continues until such time as the level of the liquid reaches the level of the discharge tube at which time liquid is rapidly drawn into the low pressure area causing the housing to move in the downstream direction thereby overcoming the restoring force of an associated spring biased valve causing the valve to seat to thereby substantially terminate the flow of liquid.