How do solar lights turn on at night?

By Matt •  Updated: 02/13/22 •  7 min read

Hands operate outdated solar lights. That means you switch on the lights during the night and turn them during the day. New models of solar panels are automatic. So lights turn on at night and turn off during the day automatically. 

Read on to understand how the new type of solar light works. 

Solar Inverter
Solar Inverter

How do solar lights turn on at night?

Three factors/ components in a solar light facilitate the machine to sense the darkness. 

  • Voltage Sensor: A voltage sensor is placed inside the circuit. It reads the voltage as the power is being generated. During the day, when power is being developed, the voltage sensor detects energy, shuts the bulb, and keeps charging during the day. At night the circuit is open. 
  • Photo Eye: A photo-eye is a small piece that detects light. When there is sun during the day, the photo eye sees and keeps the lamps off. The photo-eye detects the absence of light at night and automatically lights the lamps.
  • Motion Sensor:  This detects the presence of motion. It works well combined with any of the two discussed sensors. The motion sensor is helpful during the winter or cloudy days. 

Do solar lights stay on all night?

Unlike expensive electric energy, you cannot feel the pain of leaving your solar light lamps on during the day. And since the solar lights turn on automatically, here are some things to check if you want to know how long your solar light stays at night. 

  • Solar lasts longer when there is enough power in the batteries. If the batteries and the solar panel are in good condition, they generate energy that can survive the lamps for up to 10hrs. However, when the solar energy is low, especially during winter, the batteries do not recharge. 
  • When the batteries are in good condition, the lights stay on for long: They cannot generate energy during the day when the batteries are defective. Therefore, solar lights with batteries in good condition last longer and vice versa.
  • The type of solar panels you buy affects the time the light lasts. Some brands produce more robust solar panels. As a result, the battery charges without complication and lasts longer at night. On the other hand, the batteries drain faster and go off quickly for brands with weak solar panels. 

To determine how long the lights stay on at night, use a timer

So long as the system is installed correctly, your solar lights should stay on throughout the night. 

Why don’t my solar lights turn on at night?

Although solar energy is the cheapest energy mode, its simplicity comes with some setbacks. For example, your solar lights might not be working at night for the following reasons. 

  1. The unit is not turned on. 

After installing the solar lights, many people think they start to work automatically. Unfortunately, this is not the case as solar lights have buttons that should be touched to work. 

You might find yourself worried your solar lights are not working when it is a simple button you did not switch. 

  1. There is still a tab on the battery. 

Batteries of solar-powered lights have a tab on them. The tab blocks the circuit from flowing, thereby blocking the light. To make sure the battery is working, pull out the tab. 

  1. The solar panel is blocked

If trees or the direction blocks the solar panel installed, it does not have enough exposure to the sun. 

To make sure the solar panel generates more energy, install it at an angle where it absorbs enough sunlight energy during the day. 

  1. The solar panel is dirty

The solar panel might be blocked by dust if you live near dusty roads. As a result, the battery will not charge. Therefore it cannot work as expected. 

  1. Cover the solar panel 

Suppose you use solar light in a big city with a street light. The city lights might confuse the solar panel, triggering the sensors and turning off the bulbs. 

  1. The batteries are dead. 

The solar light might not be working at night because the batteries are not working. Solar lights rechargeable batteries charge during the day and get drained at night. 

Over an extended period, their power holding capacity will depreciate. So if your solar lights batteries are dead, replace them with new ones. 

  1. Check for broken wires

If your solar lights are not working during the day, check if animal bites are on the wires. If there is any, you can change the cables. 

Why are my solar lights on during the day?

Solar lights are automatic. They turn on during the night and go off during the day. If you see your solar light switch on during the day, your lighting system might have problems. 

Below are why your solar light does not turn off during the day. 

  1. Insufficient light exposure

If the solar panel is not exposed to sunlight during the day, especially if blocked by shadows from the trees or building, it will stay on during the day. 

  1. A blocked light sensor

The sensor is blocked if the solar panel is filled with debris and dust on the surface. It will therefore not detect when sunlight comes. 

  1. Defective sensor

If the sensor is spoiled, it will not notice whether there is darkness or light.

  1. Water Penetration. 

If water penetrates the solar panel, some metal parts might rust. In addition, the coating on the sensor might be damaged by water penetration. 

  1. Faulty wires

The wires connecting the LED and the battery might be tampered with by animals and rodents. This might disrupt the normal working of your lighting system. 

Another reason why the wires might be faulty is because of poor manufacturing. If the lighting system does not go off during its early years, you should contact the manufacturers. 

What to do if my solar lights don’t turn on at night?

Below are some of the things discussed above that you can use to fix when your solar lights are not working correctly. 

  • Check if you have connected the lighting system correctly
  • Clean the solar panels and check the sensor.
  • Change the rechargeable batteries.
  • Unblock the path of the sun towards the solar panel.
  • Deep charge the batteries. 
  • Change the sensor.
  • Pull the battery tab. 

Frequently Asked Questions (FAQs)

Why is my solar light always on?

If your solar light is on both at night and during the day, one of the components might be defective. 

The sensor might be blocked. The solar panel might be dirty or blocked by trees. 

Do solar lights work well during the winter?

No. During winter, you should remove the solar panel and put it indoors, covered with a cloth. The panel might become defective from water penetration and cold. 

How can I make my solar light stay on all night long?

You can do several things to make your solar lights last overnight. First, make sure the batteries are charging well and clean the solar panel for maximum sunlight energy absorption. 

Why do solar lights turn on during the night only?

Solar lights have a sensor that detects darkness, turns on during the night, and detects light during the day. 

Conclusion

Solar light should perform as expected for a long time. 

If your solar light is not working during the night or still stays on during the day, there are some defects in your solar lighting system. 

This article has gone into depth on the solar light sensor, batteries, solar panels, and weather conditions. If you have any issues with your solar panel, this guide can be helpful to you. 

If the solar lights are not working well when it is new or a few weeks old, you should contact the manufacturers for an exchange. 

Matt

I’m Matt, a computer and electronic embedded system developer. Currently, working as an electronic engineer. In my leisure time, I do love to blog about technology stuff. Specially, new advance high tech devices. Portable solar systems are one of topic that I love to investigate. They are becoming more powerful day by day which keep me alert.