How long do they stay lit at night?

It depends on charge. After a full sunny day expect a few hours of light; after a cloudy day, much less. Keep the solar panel in direct sun and clear of shade.

Are they safe in rain?

They are made for outdoor use and handle normal rain, but the solar panel and battery box should be mounted where water cannot pool. Bring them in for storms or winter storage.

Do I need a remote or app?

No. The 12 modes are switched with the button on the solar panel or controller. Some versions include a small remote, but do not count on one.

Can I use them indoors?

Only near a sunny window, because the solar panel needs light to charge. Indoors they will run down and go dark.

How many lights are on the string?

The set is a 12-meter string with flower-shaped LEDs spaced along it. Check the listing for the exact bulb count before planning a run.

Do they come with a battery included?

Yes, the solar panel has a built-in rechargeable battery. It is not user-replaceable on most budget sets, so the lights last as long as that cell does.