It is very important to de-register and correctly dispose of your unwanted beacons to prevent costly search assets being tasked to find garbage instead of saving lives.
There are several ways to dispose of unwanted beacons listed in the Media Release linked below.
Battery World will now be charging a small fee for beacon disposal, due to the increasing number of beacons being disposed.
Read more here:
http://www.amsa.gov.au/media/documents/050215_MediaRelease_ResponsibleBeaconDisposal.pdf
and here:
http://www.cospas-sarsat.int/en/beacon-ownership/disposal-of-old-beacons-and-old-batteries