A hydraulic accumulator including a fluid chamber and a displaceable piston that is connected to a piston position-measuring means is disclosed. Embodiments of the hydraulic accumulator can provide a device that measures the available fluid volume in the accumulator. In embodiments, the displaceable part of the piston may separate fluid volume from gas volume, and may be connected to a wire that runs through the fluid volume and exits the outside of the accumulator through a sealed opening. Further, in embodiments, the wire may be led over pulleys and through a hollow member connected to the accumulator. The position of an associated metallic core member can be electrically monitored to provide position and fluid volume information.