There comes a point with any gadget where it has to be disposed of. Whether it's becasue you've upgraded to a newer device, or the battery has finally died for the last time, or because your smartphone went for a swim, the old gadget has got to go.
The following infographic lays out an argument against simply chucking the old device in the trash. Instead you should consider re-gifting or recycling the gadget so that it might be reused. This not only helps someone else, it also reduces the damaging effects of e-waste and removes one more piece of trash from a landfill.