A motor driven fishing reel is provided. The motor driven fishing reel can include a detachable battery pack configured to supply power to a motorized drive assembly within the motor driven fishing reel. The battery pack can include a power output adaptor that can be engaged with a power input adaptor on the motor driven fishing reel. Alternatively, the power input adaptor can accept power from an external source. The battery pack can include one or more protrusions to engage with one or more receiving channels on the motor driven fishing reel such that the battery pack can easily be attached and detached from the motor driven fishing reel.