US Patent 9293792 Self-activated draining system

A method of managing leakage of liquid inside a battery system comprises: containing leaking liquid in a non-liquid sensitive region of the battery system so as to protect internal electrical components of the battery system from coming in contact with the leaking liquid; and in direct response to the leakage, expunging the leaking liquid from the battery system. A drain device includes: a body with a port therethrough, the body configured to be positioned in a wall of a container; means for opening the port in response to a first liquid contacting the drain device on an inside of the container; and means for resisting ingress into the container by a second liquid that contacts the drain device on an outside of the container.