Why your solar lights may not be working and how to fix them
Solar powered lights can be a convenient way to light up your yard. They are easy to setup and save you money that would otherwise be used to extend cabling to the lights.
So what can you do when they stop working?
Fortunately, usually the problem is not as complicated as you may think. In fact, you may be surprised to learn that a number of these faults can be fixed by yourself.
This post lists common failures of solar powered lights and how you can fix them.
# 1. Solar lights not working at night
Solar lights not coming on during the night can be caused by solar lights not charging.
- Problem with the solar panel
An easy way to tell whether the solar lights are charging or not is to test and measure if there is a voltage output from the solar panel.
Do you have access to the light?
Can you access the solar panel connection? (do not do this if it voids your warranty) If you can, using a voltmeter measure the voltage output across the solar panel positive and negative connections during the day.
A good solar panel has a voltage output equal to its rated output. A voltage output significantly lower than the solar panel’s output is a sign of a failing or dead solar panel.
Possible reasons for a failing or dead solar panel are:
- Water or moisture leaks that destroy the solar cells
- Broken solar panels
- Some solar panels particularly the cheap ones are not built to last. For example, some solar garden light lights will last for 5 years.
If a solar panel is dead, you can either replace it or if it is an all-in one unit, just get a new solar panel light.
# 2. Solar batteries are dead
You most probably have a dead battery if:
You have had at least 5 hours of sunshine and can measure the solar panel voltage across the battery but the light is dim and works for a short-time or does not work at all the battery.
This is a sign that the battery holds little charge or does not hold charge.
What to do is you suspect you have a dead solar battery:
- If the solar light is serviceable, replace the battery with the type recommended by the manufacturer.
- Make sure you charge it fully for the recommended hours, usually 5-8 hours
# 3. The solar light switch position not set correctly
Solar lights usually have either an ON/OFF or ON/OFF/AUTO switch. If the light has an ON/OFF switch, check that the switch is in the ON position for the light to automatically come on at night when the light sensor detects darkness.
If the light has an ON/OFF/AUTO switch, check that the switch is in the AUTO position for the light to automatically come on at night when the sensor detects either darkness or motion.
Note that, changing the switch to ON the position for a light with an ON/OFF/AUTO switch, tends to switch on the light regardless of whether it is dark or motion has been sensed.
# 4. Check that the battery is charged
Is the battery charged? If the solar light’s battery is not charged, then the solar light will not light.
To check if the solar light’s battery is drained or not:
- (If possible) access, remove the battery and use a multi-meter set to measure DC Voltage. Compare the the current battery voltage and with the voltage specified on the battery label.
Voltages significantly lower (e.g. 0.9V for a 1.2 V battery) the expected battery voltage is sign of a battery not charging or bad battery.
- (If possible) replace with a new or known working batteries batteries of the same size (follow the manufacturer’s instructions). If the solar light comes on, you may need to establish why it is not being charged.
- Check that the solar light’s solar panel is not shaded in anyway (it may need to be charged for a day or so after removing the obstacle causing the shadow)
- Check that the solar panel cable is plugged into the light (depends on model)
- Check that the solar panel in not damaged in any one way
Dim solar lights is usually a sign of batteries not charging fully, ageing batteries or lights set to the dim brightness switch setting.
Check the section above on “Solar lights coming on for a short time”. Click here to see the content below. for information on how to deal with batteries not charging fully or ageing batteries.
Possible causes of dim solar panel lights
- Some solar lights have a dim/full brightness setting switch. If they do, check that it is not set to the dim mode.
Note that when the light setting is set to full brightness, the battery will not last as long as when it is set to the DIM mode.
- Shading of the solar panel reducing its power output. Check and remove any obstructions casting shadows on the solar panels or if not possible, you can relocate the solar light to an area with plenty of sunlight during the day.
- Several days of cloudy weather. The lights need several hours of sunlight to charge fully and will likely dim after a short time during days of cloudy weather. Solar lights typically require 4-6 hours of sunlight to charge.
Solar lights coming on for a short time is usually a sign of either batteries not charging fully or ageing batteries. You are more likely to have ageing batteries after 1-2+ years of service depending on quality of solar lights.
Possible causes of batteries failing to charge fully
- Shading of the solar panel. Check and remove any obstructions casting shadows on the solar panels or relocate the solar light to an area with plenty of sunlight during the day.
- Several days of cloudy weather. Solar lights need several hours of sunlight to charge fully. Solar lights typically require 4-6 hours of sunlight to charge.
4. How to fix solar lights that don’t work after rain
If your solar lights don’t work after the rains, check:
- Have your lights received enough hours of sunshine? Solar lights typically require 4-6 hours of sunlight to charge.
- For water or moisture leaks that may have destroyed the solar cells or solar light circuity