Do these need direct sunlight to work?

Yes. The panel needs several hours of direct sun to charge the cell for a night of light. In heavy shade or under a roof overhang they will run dim or not at all.

How long do they stay lit at night?

Expect roughly 6 to 8 hours on a full charge in summer, less in winter or after cloudy days. Output dims as the cell drains overnight.

Are they bright enough to light stairs safely?

They mark step edges rather than light them. Treat them as accent and safety markers, and keep a brighter fixture for main stair lighting.

How are they installed?

Most mount with the included stakes into soil or with screws into wood decking. No wiring or transformer is needed.

Can I replace the battery or LED?

The LED is integrated and not user-replaceable. Some units have an accessible rechargeable cell, but plan on replacing the whole light when it fails.

When is the best time to buy?

Solar garden lighting tends to be discounted in late summer and early fall as stores clear seasonal stock. Watch the 12-pack price against smaller packs.