How can I recharge the phaser welder?

Hint 1 of 3:

You may not know this, but there's a way to use one inventory item on
another.

Hint 2 of 3:

Choose the first item from the inventory, then return to the inventory and
select the second item.  You'll use the first item on the second.

Hint 3 of 3:

You can transfer power from one item to another.