What Can I Do With A 1.5 Watt Solar Panel?

A 1.5-watt solar panel produces a tiny amount of energy. The energy it produces is so small it would not be enough to power most light bulbs. In truth, it has very limited use except for powering a very small appliance like an LED display for example.

Small solar panels are useful tools for simple applications that don’t require too much energy. But what type of application can you use them for?

Most people know or are familiar with the large solar panels that produce up to 400 watts and generate enough power for an entire house. But what can you run with the smaller 10, 5, or even 2-watt solar panels?

In this guide, we’ll explore how you can use small solar panels. For example, can you use a small solar panel to charge a car battery?

Small solar panels are a very cost-effective way to get into solar energy. It is cheaper than trying to go all in on a full solar system which has an average cost of around $20,000.

It’s also much easier as it gives you a practical introduction to how solar works. If you’re eager to get started on solar but you’re on a tight budget, then this short guide will give you some handy tips on how to do it with small solar panels.

What Can I Power With A Small Solar Panel?

Depending on the power rating, a small solar panel can be used for anything from charging a portable flashlight to powering a small refrigerator.

Solar panel technology has grown tremendously since the first mass-production panels hit the market in 1955. Back then solar cells had an efficiency of 10% and cost around $300 per watt. That means a 5kva (5,000 watts) solar panel system would set you back $1,5 million! Source

Fortunately, solar panel technology has improved while costs have gone down. Today, that same system is twice as efficient and 75 times cheaper.

Small solar panels are a great way to get started and experiment with solar if you’re unfamiliar with it. For this guide, a small solar panel is anything below 200 watts.

Small solar panels are ideal for the outdoors or at home. They’re perfect for providing the small energy needs in an RV or camper, small boats, and for camping or hiking expeditions. They can be used to power small appliances like laptops and mobile chargers, GPSs, and coolers.

They’re not just ideal for portable devices, however. They can also be used in a home to power security systems, outdoor lighting, and even small handheld equipment. There are different types of small solar panels. Knowing what types there are will help you pick the right option.

1. Rigid solar panels. These are your standard, everyday solar panels, much like the ones you see on rooftops only smaller. These can be fixed to the roof of a motorhome to provide power for smaller appliances like lights, chargers, and mini-fridges. Recommended power for these smaller panels is between 100-200 watts.
2. Flexible solar panels. These are solar panels with a flexible plastic back sheet so they can be bent. A bendable solar panel is particularly useful for RVs with an odd shape. The recommended power rating for these is also between 100-200 watts.
3. Portable solar panels. These are different from rigid or flexible solar panels in that they are several solar panels that can be folded together. As they are lightweight and foldable this makes them easier to carry in a backpack. They’re especially practical for hiking and camping. The recommended power rating for these is 50-100 watts.
4. Mini solar panels. These are the smallest solar panels you will find. They are usually no bigger than a mobile phone or small tablet. They’re typically used to charge mobile devices on the go. Recommended power rating is between 10-50 watts.

Now you have some idea of what you can do with a small solar panel. Let’s look at a few practical questions on how you might use it.

How Long Does It Take A 1.5-Watt Solar Panel To Charge A Car Battery?

At 12 volts a 1.5-watt solar panel produces 0.125 amps per hour. Car batteries have an average capacity of 48 amps. It would take around 384 hours to charge a battery with a solar panel of that size.

Charging a car battery with a solar panel that small would be impractical. To pump energy from a solar panel to a battery, the voltage in the solar panel has to be higher than the voltage in the battery. Most solar panels of that size work at a voltage of fewer than 12 volts so it would not work. Source

A battery is like a bucket that you need to fill with water. The solar panel is like the hose. The bigger the hose, the faster the bucket fills up. In this case, the hose (solar panel) is the size of a drinking straw so it would take much too long to fill the bucket (battery).

There are a few ways you can estimate the charge time of a solar panel. The simplest way is to convert the solar panel wattage into amps and then divide the battery’s capacity with the result. Using the 1.5-watt solar panel here’s what that would look like:

Convert to amps by dividing 1.5 watts /12 volts= 0.125 amps.

Then 48 amps/0.125 amps = 384 hours.

Does A 1.5 Watt Solar Panel Need A Charge Controller?

A 1.5-watt solar panel does not need a charge controller. To determine whether a charge controller is necessary divide the battery capacity by the solar panel power rating. If the answer is less than 200 then a charge controller is not necessary.

If you have a 100-amp hour battery and a 20-watt solar panel, the solar panel would produce 1.2-amp hours. Dividing 100 by 1.2 would give you 83.3. Since this is less than 200, you would not need a charge controller. Source

What Can A 2-watt Solar Panel Run?

A 2-watt solar panel can be used to power an LED display or indicator. It can also be used to charge small batteries that use a low voltage. They can also be used to maintain the charge in a car battery, provided they have a higher voltage.