1. So how long do solar lights last?

Generally speaking, the batteries in outdoor solar lights can be expected to last about 3-4 years before they will need to be replaced. The LEDs themselves can last ten years or more.
You will know that it is time to change parts when the lights are unable to maintain charge to illuminate the area during the night.
There are a few adjustable factors that can also affect the lifespan of your outdoor solar lights.

For one, their placement in relation to other artificial lighting can diminish or enhance their longevity. Make sure that your outdoor solar lights are placed in direct sunlight at a distance from street lighting or house lighting, as too close of a proximity can throw off the sensors that cause them to kick on in low lighting.

Apart from their location, the cleanliness of the solar panels can also be a factor in solar light upkeep. Especially if you have your lights located near a garden or other typically dirty area, be sure to wipe off the panels every other week so that they get sufficient sunlight.

While most lighting systems are designed to withstand various kinds of weather and climates, they function best when they can receive a full day of direct sunlight and are not at risk of being covered in snow or knocked over by severe winds. If you are concerned about the weather at particular times of year affecting your solar lights, consider storing them for these periods.

2. How long do solar lights stay lit?

If your outdoor solar lights receive enough sunlight for a full charge (usually about eight hours), they will be able to illuminate all evening, starting when the light gets low, around sunset.

Sometimes lights will stay on longer or shorter, a problem which can usually be attributed to how well the panels are able to absorb the light. Again, checking to make sure that your lights are in the optimum spot (in direct sunlight, away from shadows or covered up by plants) can help ensure they are performing at their best.

If you are concerned that the batteries in your lights are being overused, consider either setting a timer for the lights or turning them off and/or putting them away for some periods of time. You may want to also test a few different locations before deciding on a permanent place for your lights.

3. Solar light lifespan troubleshooting tips
You may find that in the course of your light’s life, that you encounter some problems with their functioning.

Common problems include the battery dying, weak light due to poor sunlight absorption, or general light malfunction. These issues can likely either be attributed to the age of your solar light or the cleanliness of the solar panels themselves.