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When shopping for or buying a set of solar lights (see Amazon), you may notice they come with an on/off switch. It seems rather counterproductive seeing as how they operate automatically and power from the sun’s UV rays. So, why is there a power switch on solar lights?
The main reason why there are power switches on solar lights is to provide the user with more control and flexibility. So, although they do turn on and off automatically, the switch gives the option to turn them off in certain situations. Cleaning purposes and outdoor stargazing are just a couple of examples.
Understand though, not all solar lights come with an on/off switch. This is usually a feature that people opt for when purchasing them. But it will depend on what a person wants the lights for and how they intend to use them. Therefore, switches often come on solar powered spotlights and security lights rather than decorative ones.
What are the reasons for an on/off switch on solar lights?
There are several reasons why some models of solar lights have an on/off switch. For the most part, it has to do with giving the user more flexibility and control over the lights.
Switching the Light Off
Some situations where turning off the lights are handy could be:
- You need the lights off to watch the stars in the night sky.
- You’re having a party in the backyard at night and want to ensure there’s enough power for the occasion.
- To be able to use indoor solar lights the way you would any switch on a wall.
- You want to clean off the lights or the panel, so having them off is ideal.
- In the event you’re transporting them or having to store them for a long time, keeping them off will be imperative.
Having the Switch On
On the other hand, turning them on when you need them can also have its benefits:
- You want to inspect one for damage because it isn’t turning on with the rest of the lights.
- You need light to view something in twilight or at daybreak.
- It’s cloudy and dark during the day.
Is an On/Off Switch Required for Charging the Solar Panel?
Solar lights come on and take in the sun’s rays automatically, so they aren’t required for the process of charging the solar panel. Most models charge the battery even if the switch is in the off position. Therefore, it shouldn’t make a difference whether the switch is on or off for charging.
But the only way to be certain of this is to read the manufacturer’s instructions fully. There are a few models that do require the mechanism to be off while some others need the switch to be on.
That said, keeping the lights off actually allows the battery to receive a full charge over the course of several days via sunlight. So, it may be a good idea to switch them off once and awhile to ensure the batteries hold a decent charge.
If There Is a Switch, Does It Have to Be on?
When you get a new set of solar lights and there’s a switch, you should turn them in the on position once you install them. Unless you’re going to mount the lights up high, then first turn them on before installing. But this will depend on the manufacturer’s instructions as well as the quality of the lights.
However, you shouldn’t have to turn them on to use them since the circuitry does this. They come on when the sensors detect the onset of nighttime.
How do solar lights turn on and shut off?
Although various manufacturers design their solar lights differently, there’s one basic way that applies to all devices since most incorporate an LED light. These have a minimum threshold voltage in order to operate. Most decorative-style lights have a 3.5 volt threshold. We’ll use this for the sake of example.
Larger Voltage Powers the Light
There are two different circuits within the light. The first circuit receives a current of 1.2 volts while the other gets 3.7. Therefore, the one with 3.7 volts is the one that sends a current to the LED light at all times.
This means the circuit with the highest voltage is the one that powers on the light. But it doesn’t come on until the 1.2 volt senses the onset of darkness.
Smaller Voltage Takes in Sunlight
The 1.2 volt circuit receives sunlight through the solar panel and operates all day. But the power that comes into this circuitry isn’t enough to power the light itself. Upon nightfall, the 1.2 volt circuit no longer receives light, drops voltage and shuts down.
At this point, a triggering mechanism shifts the device to power the 3.7 volt circuit. But, it takes energy from the battery, not directly from the solar panel. When the amount of energy in the battery exceeds the minimum threshold of the LED, the light turns on.
Do people experience problems when an on/off switch is present?
As with anything, there are always potential problems with the on/off switch on a solar light. The most common one is how people are unaware of the existence of the switch. After charging and the lights don’t come on, they don’t understand why it’s not working.
The other common issue is not knowing there’s a switch and then mounting it up on a roof or a ceiling. Once installed, the on/off switch is difficult to access.
How do you know if the switch is on or off?
Some models of solar lights may have a switch, but they don’t mark which position is on or off. So, when in doubt, charge the panel up to get a bit of power and then put your hand over the panel to mimic nighttime conditions. When the light turns on, you know which position is on.
Are batteries included with all solar lights?
Yes, every solar light setup comes with a solar cell Ni-Cad rechargeable battery along with an LED light and a photoresistor. Each solar cell of the light produces energy to charge the battery during the day. At night, it uses that energy to power the light on.
The purpose for having an on/off switch for a solar light is mostly about preference, usage and whether a manufacturer includes one or not. Most of the time, they’re on spotlights and security lights more than decorative ones. But this can be useful in certain situations.
For instance, you may want to keep them off to ensure the battery stays charged for a backyard party you’re having at night. Or, maybe you want to turn them on during the day because it’s dark and cloudy. But the switch itself doesn’t have to be on or off to receive a charge.
However, they should be set in the on position so they light up when you need them most. Unfortunately, some people are unaware their solar lights have a switch and find themselves perplexed when they don’t seem to work. So, it’s imperative to read all the instructions before charging, installing and using the solar lights.