Solris™ Colorful Waterproof Solar Pool Light

After a full day of sun they run for roughly 5 hours — in practice, from dusk until the early hours. Run time is shorter in midwinter and after a run of overcast days, because the battery simply has less charge to work with.

Six to eight hours of direct daylight gives a full charge. Site them where nothing shades the panel for most of the day — a fence, a gutter or an overhanging shrub costs more run time than people expect.

Yes. Solris™ Colorful Waterproof Solar Pool Light is rated IP66, which covers rain, snow and the sprinkler that hits it every morning. They can stay outside through the year; the only seasonal job is wiping the panel clear.

No. There is no cable, no transformer and nothing to connect to the mains, so there is no trench across the lawn and nothing added to your power bill. Push the stake into the soil or fix the bracket to the wall, and that is the installation.

Four things account for almost all of it: the pull-tab under the battery cover is still in place on a new light; the switch is off; the panel is dusty or shaded so it never charged; or it is sitting close enough to a porch light or street lamp that the dusk sensor never thinks it is dark. Work through those in order before assuming a fault.

Yes, with a shorter run time. The panel charges from daylight rather than direct heat, so an overcast day still puts charge in — you simply get fewer hours that night. Snow sitting on the panel will stop it, so brush it off.

The rechargeable cell is good for a couple of years of nightly cycling before you notice shorter evenings. It is a standard rechargeable, so replacing it costs a few dollars rather than the whole light.

For a path, one light every six to eight feet gives a continuous run without it looking like a runway. For steps, one per two or three treads is enough. That is why these are sold in packs — the per-light price drops as the pack gets bigger.