Arcane Battery

This object appears to be a bundle of think intertwined wires, coiling into one another. It can be worn as an amulet. It is used to store spell slots for later use.

Use:

• The battery can store up to five charges. As an action one of the charges can be withdrawn from the battery to restore an expended spell slot of the user. 

• The battery can be used to recover up to a fifth level spell slot, but requires the user to concentrate of the amulet for a number of actions equal to the number of charges withdrawn. For example, it would required 4 actions to recover a forth level spell slot, which would take 24 seconds. 

• How the charges are distributed across the spell slots it decided by the user. For example, the user could withdraw five charges, and regain one second level, and one third level spell slot.

• Regaining spell slots requires physical contact with the battery. 

• This object does not allow casters to use higher level spell slots than they can cast naturally. 

Recharging:

• This amulet does not recover charges over time. A caster with spell slots remaining can spend some time to refill the amulet's charges. To refill the amulet it requires five minutes per charge recovered. Once the battery has been charged, the caster will have expended a number of spell slots equal to the number of charges given to the amulet.

• The recharging process counts as light activity, and can be performed during short and long rests.