The battery pack provides the power source for a sonic device, which emits a high-pitched noise when turned on. Lewis Dodgson used this device to deter the dinosaur parents and steal eggs from the nest. It plugs into the sonic device, and can be clipped onto a belt. When Dodgson and companions Howard King and George Baselton attempted to steal Tyrannosaurus eggs, the battery pack became unplugged from the sonic device. In the resulting Tyrannosaur attack, the battery pack fell from Dodgson’s belt and was subsequently lost in the jungles of Isla Sorna.