Answer : If your solar lights are not making it through the night, there may be multiple reasons behind it. Here are a few:

Not Enough Sunlight Exposure:

Problem: The solar panel has inadequate direct sunlight during the day, hence cutting short charging of its battery.

Solution: Keep the solar panel in a position where it receives maximum sunlight and will not be partially or wholly shaded or covered by any obstructions during any part of the day. Clean the panel regularly to remove dirt or other sediment that may block sunlight.

Old or Faulty Battery:

Problem: Over time, your solar lights' battery may no longer be able to hold a full day's charge, substantially reducing its night-time operational time.

Solution: Replace with a new, high-quality rechargeable battery of the same type. Solar light batteries should ideally be replaced within 1-2 years for proper functioning.

Do solar lights charge on cloudy days?

Problem: During winter or on cloudy days, the sun is generally low and sometimes insufficient to charge the solar lights for the whole night.
Replace your batteries with larger ones if possible. Especially during the off-season with fewer solar hours. You might need to adjust the run-time if the lights permit that.

Power Consumption:

Problem: Your solar lights may be power-hungry due to features such as advanced brightness or too many LEDs, that result in shorter run times.

Solution: Adjust the light settings into dim or install energy-efficient LED bulbs that will help in drawing less power.

Faulty Light Sensor or Circuit:

Problem: If the light sensor, or the circuit controlling it, were to fail, the lights would turn on too early or maybe not turn off too late, which could waste battery life.

Solution: Check the sensor for blockage by any object or accumulation of dirt; clean if necessary. Otherwise, you might want to replace the light or the sensor.

2) Does a solar light charge when turned off? 

Answer : Yes, a solar light will charge even if it is switched off. The charging process in no way depends on whether the light is on or off. Solar lights have a solar panel that changes sunlight into electricity, then stores it in the battery. This happens as long as the solar panel is in direct sunlight, regardless of the position of its switch.

3) 

how to fix a solar light that stops working? 

 What should I check first if my solar light stops working?

Could the battery be the reason my solar light isn’t working? How do I test it?

How can I tell if the solar panel is causing the problem?

What role does the light sensor play in my solar light not working, and how do I fix it?

Could weather conditions affect my solar light, and what can I do about it?

Is cleaning the solar panel important? How do I properly clean it?

What should I do if replacing the battery doesn’t fix my solar light?

Is it possible that the solar light's placement is affecting its performance?

Can I perform a reset or restart on my solar light? How do I do it?

When should I consider replacing my solar light if it’s not working? 

Answer : What should I check first if my solar light stops working?

Solution: First, check whether the solar light is switched on. Some designs include an on/off switch. Check the angle of the solar panel to ensure it has a good supply of direct sunlight during the day.

Might it be because of the battery that my solar light is not working? How can I test it?

Solution: Yes, it might be the battery. Remove it, and put in a new fully charged battery of the same type. If now it works, then your battery had a fault and due for replacement.

How will I know if the problem is in the solar panel?

Check for dirt, debris, or damage to the solar panel. Clean any blockages off the face of the panel with a damp cloth. Ensure that the panel is in a position to have direct sunlight for most parts of the day. If it is damaged, consider replacing the panel.

How does the light sensor make my light not work and how to fix it?

It turns on/off depending on the ambient light, which is controlled by the light sensor. The sensor may not work correctly if it's blocked or faulty. Clean the sensor to remove any dirt or obstructions. If cleaning doesn't help, it might need replacement.

Will bad weather affect my solar light, and what can I do about it?

Question: Will continuous cloudy or rainy weather reduce the light's charging capacity?

Response: Yes. Prolonged cloudy or rainy weather will reduce the charging capacity of the light. Place the solar panel at a location with best sunlight. You may also want to bring the light inside during extreme weather protecting it.

Does the solar panel need cleaning? How should I clean it?

Cleanliness is the key to perfect functioning. Wipe the panel clean with a soft cloth and warm water. Avoid harsh chemicals or abrasive materials that may scratch the surface.

What if my solar light doesn't work after replacing the battery?

Solution: If changing batteries does not work, check the wiring connections for loose or damaged wires. Tighten the loose and replace the damaged wires. Otherwise, if it still doesn't turn on, it has internal faulty components.

Has its placement been affecting the performance of the solar light?

Solution: Absolutely. Place the solar light in a location where it will receive direct sunlight for most of the day. Try not to put it under trees, awnings, or anything else that might block sunlight.

Can I reset or restart my solar light? How do I do it?

Solution: A few solar lights have the option for resetting. Simply turn the light off, remove the battery for a few minutes, then replace it and turn the light back on. Sometimes this does the trick.

When should I replace my solar light if it's not working?

If all troubleshooting steps from cleaning to repositioning to replacing the battery have been done, and it still doesn't work, then maybe it is time to replace the unit. Consider the age and warranty status of the light when deciding.

Clear  Further doubts or Questions Related with Solar lights go through the link below 

https://www.hardollenterprises.com/pages/solar-light-related-common-doubts