If the batteries themselves don ' t have protection circuits built in then yes , that ' s possible . Cell phone batteries have very small and usually indented contact points however so it ' s less likely . Edit actually I don ' t know . Cell phone batteries usually aren ' t built to supply such a large current as an 18650 . I ' m not sure if it would generate enough heat to self ignite , the internal resistance might be too high . <| sep |> Can someone explain to me how the Raid Finder works ? The game never gave me a tutorial when I unlocked Sephirot Ex . Does Duty Incomplete only queue me with other people who haven ' t done the fight yet ? If so , is there a way to queue with other people who have cleared it already ? <| sep |> History of the church , volumes 18