Backpack of Teleportation

This ordinary-looking backpack has the Thrown properties (range 30/50). This backpack has 3 charges. As an action and by spending a charge, you can teleport to the backpack’s location(the backpack must be on the same plane as you for you to teleport to it) the backpack will magically appear back on your back.  The backpack can carry up to 50 lbs. The backpack regains 1d3 charges per dawn.