"A shimmering silver cube, this cell will slowly recharge if left in sunlight."
A Solar Cell is one of the various types of Energy Cells available in Caves of Qud. While it has a lower charge capacity than other cells, it will recharge if carried in your inventory and exposed to sunlight. Generates 10 charge points per turn during the day, if not underground.
Note that it will still charge when socketed in an item, whether that item is worn, wielded or carried.
For purposes of charging the cell, daylight starts on turn 250 of current day and ends on turn 912. A day lasts 1200 turns.
As an unidentified Artifact, it may appear as "small trinket" or "small cube".