Scroll of charging

From Wikihack

The scroll of charging can be used for charging: adding charges to various objects, or (if you read it while confused) recharging your energy.

You can recharge all wands, rings that have numeric enchantments (such as adornment), and the tools that have charges. There is a risk that rings (or wands that have previously been recharged) will explode.

Because of the scroll's function, two blessed scrolls of charging are often the best first wish to make from a wand of wishing, to use when its initial charges run out. A blessed scroll of charging will typically restore more charges than an uncursed scroll.

A cursed scroll of charging will not restore any charges, although it will still increment the charge counter, set the current number of charges to zero (or decrease a ring's enchantment by 1-2), and possibly cause wands and rings to explode.