A321
Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Situational Awareness
Deviation / Discrepancy - Procedural Hazardous Material Violation; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Became Reoriented; Flight Crew Overcame Equipment Problem
Procedure; Human Factors
During en-route; we got a message from [Dispatch] advising us that a passenger who did not make the flight had checked a bag that made our flight with a Lithium Battery. Upon further investigation with Cargo Supervisor; we found out that it was a small 20 volt 2.0 amp 40 watts per hr spare not attached to the drilling tool. I spoke with [the Dispatcher] and asked him to speak with his Supervisor as well as Chief Pilot to seek their recommendation since we were overweight and had to [request priority handling] that could have created a bigger issue. I agreed with them and made a decision to continue to [the destination].
A321 Captain reported airborne Dispatch notification of passenger cargo bag containing unconnected Lithium Battery onboard belonging to a passenger who did not board flight.