A combined dual ganged manifold and cover arrangement for batteries features channeling of gas flow to an explosion attenuation device located between the manifolds and a cover designed for maximizing return to the battery of any electrolyte which may contact the cover from vibration, tilting, overheating, overcharge and the like. Splash barrels within the cover include a unique acid level indicator, and feet are provided on the manifold to prevent the manifolds from inadvertently being used with other cover designs. The arrangement is particularly useful for batteries having terminal posts lying along the battery centerline. The cover utilizes external and internal gas pick-up systems and perpetual hill and infinite well concepts to control acid flow. A narrow channel reduces standing wave electrolyte surface violence.