To quickly answer why do my solar lights come on during the day, let us show you how they work, potential reasons why they are not working properly and the tips to fix the common potential problems for why your solar light won’t turn off.
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The answer to when do solar lights come on, is when they decide it’s dark enough to need light. Solar lighting is not connected to a normal lighting circuit with a switch but operates autonomously. This automatic on off solar light circuit takes it power from rechargeable batteries and switches by using an internal photocell sensor that tells the light fixture whether it is day or night.
This photocell sensor is really sensitive to light and once the sun starts coming out and reaches above a certain point, the sensor will tell the fixture that it is daytime not night time.
The fixture will then turn off the solar light so it can charge during the day and store the energy for use at night only.
When evening comes along, the sun goes down and the photocell senses the lack of daylight. The fixture turns on the lights as night approaches because there is not enough sunlight left for charging and is ready for work. This process happens at sunrise and sunset every day and is called a dusk to dawn sensor.
Your solar lighting fixtures are dependant on it’s internal dusk to dawn sensor working efficiently so let’s start with this as it is the most likely culprit to your question of why my solar lights stay on in the day. If the photocell sensor is damaged or broken it will not able to tell the difference between night and day.
Where is the sensor on solar lights? Locate the PV panel on the solar light, it will be a black square or rectangle with lines across it, as contained within this window will be the photocell which isn’t always easy to see with your eyes. Cover the entire panel with your hand or a cloth and if you have more than one panel on your light fixture make sure they are covered.
During the day this would usually trigger a night time mode as it senses the loss of light. If nothing happens move on.
The sensor window on your solar light fixture is very sensitive to the sun. If it gets dirty or covered with debris and dirt, then it will not be able to properly sense when there isn’t enough daylight and tell the lights to turn on in the evening.
So clean this black plastic window thoroughly and check if that fixes the problem. In a lot of cases a bit of windex usually will do the trick. Your lights may be working fine again – as you clean it, it will turn off once left to sense the light levels. Try covering the panel with a cloth or your hand again to mimic night time – off and on to see if the changes in light level start to trigger the switch again.
Check if the solar panel is exposed to direct sunlight as this can cause intense heat build up and damage the internal photocell sensor.
If you are experiencing problems with your solar panel getting too hot then the question of how to fix solar light sensor at this point is to re-position the panel towards the direction of the sun when it isn’t at it’s hottest or ensure it has part shade for some of the day.
In lighting fixtures most internal photocells are an integral part of the PV panel and certainly not a part you can order and replace, unlike some suggestions from other people online. Mass produced lighting is not designed to be modular and fixable.
If your solar lights are still coming on in the day then something else is at fault and more investigation will be required to find out what it is.
If you have checked that all components of your solar light system are clean and working fine, you will need to check the wiring.
If your solar lights not working by not turning on at night but coming on during the day then there could be a problem with the wiring. The most likely of which would be coming from damaged or loose connections in the system or it is connected incorrectly to some other power source that keeps them turned on all day.
This would especially be the case if you’ve moved the light to a new location as it needs to have uninterrupted power from the sun to work.
I suggest checking every connection and making sure they are secure – there should not be any loose connections anywhere within your system. If that is sound then I recommend digging out the original manuals or instructions that came with the lights to make sure everything is connected as per the diagram before checking anything else.
If you have already checked the photocell and it is working correctly, and there are no loose connections anywhere within the system then it’s a sign that there isn’t enough charge from your solar panels to power the lights properly. Malfunctions can happen when the battery runs low on power.
If you ask anyone with solar lights they will tell you that at some point their batteries have died. Especially if the person is using cheap or affordable solar panel kits, one of the most common things that will cause a power shortage is low quality batteries.
Batteries are like any other battery powered device – all can be effected by extreme temperatures both hot and cold.
If there is a problem with the wiring to the lights, you may still be able to fix it by replacing the batteries with better quality ones. This is of course only if your panels are actually producing charge from their solar cell.
Using new batteries can sometimes revive old solar lights as well as new ones that have stopped working. New batteries are good but they also need to be charged correctly.
If you’ve checked every part of your system and they are all working fine, then I would recommend replacing the solar panel itself after so many years it probably needs to be replaced anyways. This is one of the last resorts of course and not possible with alot of the lower cost solar lighting but if you had access to spares from another light system it would be possible to swap.
Once all these physical checks and replacements have been done it’s time to let the light fixture rest and fully recharge over 72 hours. Locate the switch on the back of the panel and ensure it is off. Fully charge the batteries as if it were a new product ready for it’s first night time use.
When you turn the product on to be ready for use, check to see the switch is fully over. A potential short could occur if the product is confused to whether you want it to be on or off and end up just being on all the time.
Another reason for outdoor solar lights always on could be moisture in the electronics. Depending on where you live or if you are getting the occasional heavy rain then you may find that water has entered your solar panel. This can be detrimental to it’s performance but is easily fixed in some cases.
Check for water damage by looking to see if there are signs of condensation behind the panel’s plastic front, get a hairdryer and remove all the excess moisture. Dismantle what you can only in the knowledge that you can put it back together properly and dry it off and leave exposed for a day to evaporate all moisture. PV panels are often sealed permanently
This is one of the most common causes for solar lights to stop working properly is water damage combined with many other possible problems that would likely be beyond your means to repair.
If you have a professional quality lighting product then replacing certain components could help solve some issues, but the manufacturer would need to offer these parts and you would need to be competent enough to tackle some basic electronic tinkering.
If you can’t fix that then it’s time replace the panel altogether.
If your solar lights are still not turning on after all these steps you may have a faulty fuse or circuit breaker within the lights themselves. If this is the case then I would recommend contacting the manufacturer and asking for support and help in finding which part needs replacing to solve your issue.
If you have purchased a longer warranty with your solar panel kit then please check to see if they cover the external parts as well and that this issue is covered by their support centre. If so please contact them directly for help and assistance on how to best get the lights working again.
If your lights are on in the day and off at night, this is a really interesting issue as much of the fixes we have discussed could cause an irregular malfunction so do check them out.
As discussed above your solar lighting is turned on at night through the internal photocell light sensor switch, and this could be beginning to malfunction. So you will need to locate and identify if this is the cause of your solar lights turning off at night by seeing if covering the solar panel still triggers an off and on function. If so then the sensor is either not getting enough power to correctly sense or most likely is about to stop working so this could be the time to start looking for a new product – sorry!
Nine times out of ten, your stay on solar lights are due to dirt on the solar panel, so if you haven’t started yet make sure you start with a good clean up. It could also be the problem with sensors or batteries; however other issues can cause this as well.
If you just cannot find the right remedy and need a new solar light then check our our buying guide and reviews of our selection of the best solar lights that we have tested and can recommend!
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