Harbor Freight Solar Panel Review
Solar panels can be the perfect option you are looking forward to in order to bring a new way of generating energy to your home. Not only is it a much-needed source of reliable energy, but it also reduces, sometimes greatly, your energy bills and has very low maintenance costs. Nonetheless, finding the right solar kit in the vastity of options might be overwhelming.
In our article, we are going to talk about Harbor Freight solar panels. It is a discount tool and equipment retailer and sells a variety of solar kits and other products related to solar power. We are going to honestly review the most popular to give you an idea and orient you towards the best choice.
Harbor Freight Solar Panel Kit
Let’s first FOCUS on Harbor Freight solar panel kits. The company is currently selling two of these products: the 7 Watt and the 100 one.
Description
This product is the retailer’s top pick and is recommended by 97% of their customers. It is a portable and reliable solar energy kit that delivers 100 watts of free, clean, and quiet energy. The cells work perfectly well in different weather conditions, including in both sunny or cloudy circumstances. Such advantage comes from the fact that the cells are in amorphous silicons, so you can be sure they will give you the best output regardless of the sun’s presence or absence.
The kit is also very simple to set up and then maintain. The reason being, it comes with a set of tools such as mounting hardware, a 12v light kit, battery terminal clamps, and a universal power adapter. These tools make it easier not only to place the panel in the desired place but also to keep it in good condition.
To guarantee the best performance, the panel uses technology such as solar charge controllers or blocking diode technology, which prevents your panel from losing charge during the night. This happens because it allows the flow of current to the battery but blocks the opposite flow of current, i.e., from the battery to the panel.
Pros and Cons
- Weather resistant works in both cloudy and sunny conditions.
- Very easy to put up, as well as to maintain.
- Comes with mounting hardware and a USB port for charging your devices.
Introduction: Assembling My Harbor Freight 45 Watt Solar Panel Kit. No Tools Needed!
I originally wanted to design my own solar panel controller then buy the best deal in solar panels out there I could find. While doing my research I kept coming back to the Harbor Freight 45 Watt solar panel kit because it looked like for less than 200 (at the time) the kit would do everything I wanted to do with solar power.
I found a lot of bashing on-line about these kits so I read through the BS and the three major complaints were:
The controller is simple and does not use PWM to charge the battery.
But it’s a 45 watt system for less than 200. What do you expect for less than 200.
It’s only 45 watts.
This is OK for me, I’m planning to just run a couple of lights and maybe a fan and none of these will be on for very long.
The controller that comes with this kit does not include a low voltage cut-off needed to protect the battery.
This is absolutely not true and I found the schematic on-line to prove it’s not true. Then I took the cover off the controller to analyze the circuit myself to verify the schematic is correct. This controller does include a low voltage cut-off to protect your battery from over discharge.
The positive points were the kit seemed to have everything I need except for a battery and maybe a power inverter! Also, everything appeared simple to hook-up.
I wrote this instructable as a review of Harbor Freight’s kit, but the real reason I bought the kit was to install solar lighting in my storage building. You can see the full install in this instructable.
Step 1: I Bought and Unpacked the Harbor Freight Kit
I finally had about 200 to spare and I bought the Harbor Freight kit. My first surprise was how heavy this kit was. it’s almost 60 lbs!
Next I unpacked the solar panels. each solar panel was protected by a pair of styrofoam panels. I also discovered why the box weights so much. The solar panels are very heavy for their size.
The next surprise came when I unpacked the tubes that assemble into a frame. I expected some cheap thin PVC tubing. What was in the box was still plastic but the plastic was very heavy. Also, everything was clearly labeled.
The other major parts. the controller and light were packed in a box inside the main box and the interconnect wiring was in with the plastic frame parts.
Step 2: Assembling the Frame
The kit comes with two sets of screws wing nuts. The shorter screws are used to assemble the frame. Everything goes together like the picture on the outside of box and like this instructable title says. no tools needed. You just drop the screws through the holes then tighten the wing nuts. A Philips (cross tip) screw driver won’t hurt if you want to snug everything down tight, but it’s not absolutely necessary.
Step 3: The Working Parts of the Kit
Like the box says. everything’s included except the battery and a power inverter (assuming you need one), but I don’t need one because I’ll be using the two 12VDC florescent lights included with the kit.
Step 4: Solar Panel Assembly
The solar panels themselves attach to the frame with the same style screws and wing nuts that are used to assemble the frame, only they are longer and include a small flat washer. The panels each attached with four screws, 2 on the top and 2 on the bottom.
The frame itself has two swing out legs and you set their angle with two of the screws left over from assembly. This makes it easy to set-up the panel, then take it down when not in use. If you like camping it would be easy to stow this somewhere in your Vanagon or camper then drag it out and set it up in just a few minutes. A Philips (cross tip) screw driver won’t hurt if you want to snug everything down tight, but it’s not absolutely necessary.
Step 5: Wiring It All Up
Wiring is simple. it’s all plug and play.
The three solar panel cords plug into the 3 way adapter that comes with the kit and you can’t plug the wires in reversed. Then the main cable plugs into the other side of the adapter.
The ring terminal end of the cable attaches to the solar panel side of the charge controller back panel. Everything’s color coded and just like the first part there’s no tools required.
The battery charge cable attaches the same way.
I was concerned about cable length so I stretched the solar panel main cable down my driveway and measured the length. The longest tape measure I have is 25′ but based on the length left over, it looks like the overall stretched-out length is 30′. This means you can park your camper or Vanagon in the shade and drag your solar panels out into the sunshine. Or if you are setting your solar panel up for emergency lights there is a good chance you can set the panel far enough away from the house to catch some light.
The two florescent light cords are pretty long too. 16 feet per my measuring tape.
Step 6: Connecting the Battery and Lights
The final step is connecting the battery. I went ahead and connected to a marine battery I had laying around and before I turned the controller on I disconnected the solar panel just to see what the voltage was. It’s pretty low. 9.8 volts but it’s also a very discharged battery
Next I connected the solar panel back up and the battery reached 12.8 volts pretty fast. This is a good sign for the solar cells. they are producing power. But it looks like I’ll be replacing this battery because the voltage should not have come up this fast!
Once I had charged the battery for about an hour I tried the lights. They seem to work well.
Step 7: Technical Stuff. for Anyone Who Cares
I chased down the schematic for the Harbor Freight charger and it’s pretty impressive for what it is.
The charger uses a comparator circuit and a reference voltage to switch the solar cells on and off. This is important because you don’t want to over charge your battery.
The charger uses a second comparator circuit and the same voltage reference to disconnect your loads when the battery gets too low. This is just as important because discharging your battery too much will destroy your battery.
Step 8: Conclusion
It seems to me that this kit would be a great addition to anyone’s camping gear. You should be able to run lights and maybe a small exhaust fan inside your camper.
You could also set one up for emergency lighting in case of a power loss. This happened to us a few years ago in North Alabama and I was fortunate enough to have a couple of gas lamps to light up the house.
But this Harbor Freight kit has some limitations. You won’t be able to run a A/C unit or small refrigerator or freezer. These appliances need a power source much larger than this kit will provide.
So, what do you need to run a typical freezer in an emergency?
Per my deep freeze data plate it need 5 Amps and 5 Amps X 120 Volts is 600 Watts. Run this freezer for an hour a day and it will consume 600 Watt/Hours of power. I’m quoting an hour because I discovered that, at least with my freezer, an hour a day was enough to keep my food frozen and safe.
Assuming the Harbor Freight kit charged at full power for 10 hours / day, and it won’t unless you live someplace like Arizona, it will only charge 450 Watt/Hours of power a day. This is far short of what I would need to run my deep freeze an hour a day. Your situation would be a little different based on the freezer you own, regardless this kit won’t work.
So, what do you really need to keep your frozen food frozen in an emergency? I figure about a 300. 400 Watt solar panel, a charge controller rated for your solar panel’s wattage and enough batteries to store that energy will do. A off grid solar panel kit from Home Depot will cost you about 1400 and you have not bought the batteries yet. A generator is cheaper.
I wrote this instructable as a review of Harbor Freight‘s kit, but the real reason I bought the kit was to install solar lighting in my storage building. You can see the full install in this instructable.
How Long Do Harbor Freight Solar Panels Last?
Many homeowners have understandable concerns and reservations as to how much new Harbor Freight solar panels will cost and whether they will last.
To help you make an important decision, we have put together all you need to know about Harbor Freight solar panels, and how long you can expect them to last.
What Are Solar Panels?
Solar panels are small devices that convert sunlight into usable electrical energy. They consist of photovoltaic cells made of silicon or thin-film semiconductor materials.
These cells are arranged in series and parallel circuits to create different voltages. A voltage regulator then converts the various voltages into one continuous DC (direct current) output.
The basic components of a solar cell are:
- Photocathode – The part of the cell that absorbs light and generates electrons.
- Photoemissive Layer – The part of the photocathode that emits electrons.
- Electron Transport Layer – The part of the photoemissive layer that transports electrons to the next component.
- Contact Layer – The part of the electron transport layer that contacts the metal electrode.
- Metal Electrode – The part of the contact layer that conducts electrons to the outside world.
A typical solar panel consists of multiple solar cells connected together in series and/or parallel circuits. Each circuit produces a certain voltage.
Therefore, to achieve higher voltages, more solar cells must be connected in series.
To increase the amount of power produced by each cell, more cells must be connected in parallel.

Types Of Solar Panels
There are three main types of solar panels: amorphous, crystalline, and hybrid. Understanding the differences between these will help you make a more informed decision when purchasing your solar panels.
What Are Amorphous Panels?
Amorphous solar panels are also known as amorphous silicon (a-Si) cells. These panels are very popular among homeowners who want to install solar panels but lack the budget to buy a complete solar panel system.
They are generally less expensive than crystalline silicon panels, which makes them an attractive option for many people.

However, because amorphous panels use amorphous silicon instead of crystalline silicon, they don’t produce as much power per square foot.
This means that you need to be careful when deciding where to locate these panels.
If you live in a hot area, you may want to avoid placing them in Windows or vents because they won’t generate enough heat to offset the loss of electricity.
What Are Crystalline Silicon Cells?
Crystalline silicon cells are the most common type of solar cell found in residential solar systems today.
They are extremely efficient, meaning that they convert sunlight into electrical energy at a high rate. Because of this, they are often referred to as “high efficiency” solar panels.
Crystalline silicon cells are manufactured using a process called Czochralski growth.
The raw material used in this process is silicon, which is melted and pulled through a furnace. As it cools, the molten silicon solidifies into wafers.
Once the wafer is formed, it is sliced into individual pieces. Each piece is coated with a layer of phosphorus and boron atoms, and then dipped into a solution containing antimony.
After being washed, the crystals are dried and ready to be used in solar panels.
The advantages of crystalline silicon solar panels include their durability and reliability.
Unlike amorphous silicon panels, crystalline silicon panels tend to last longer without requiring any maintenance.
Additionally, they are more resistant to damage from weather conditions such as rain and snow. However, they cost more than amorphous silicon panels.
The disadvantages of crystalline silicon solar cells include their higher weight and lower output compared to amorphous silicon cells.
In addition, they require a lot of space to operate. For example, each crystalline silicon cell needs its own inverter, which converts DC current into AC current.
What Are Hybrid Solar Panels?
Hybrid solar panels combine both crystalline silicon and amorphous silicon cells in one panel.
This allows homeowners to get the best of both worlds: high efficiency and a long life span.
Like crystalline silicon cells, hybrid solar panels have a relatively low initial price point.
However, like amorphous silicon panels, they can still be quite costly.
The main advantage of hybrid panels is their ability to provide a combination of high efficiency and a long lifespan.
Both types of cells work together to create a balance between power generation and longevity.
Lower your electric bill, increase your property value, reduce your tax liability, and help save the world.
Why Choose Harbor Freight Solar Panels?
Harbor Freight solar panels are made from high-quality materials and are designed to be durable, reliable, and easy to install.
They come with everything you need to get started right away – including mounting hardware, installation instructions, and even a free power inverter.
The panels themselves are also very affordable, so it’s not hard to see why these are one of the most popular options for residential solar panel installations.
Types Of Harbor Freight Solar Panel
Harbor Freight offers a variety of different types of solar panels that are suitable for different applications. These include:
- Standard Solar Panels: These are perfect for homeowners who want to add solar panels to their homes. They are typically mounted on rooftops or ground-mounted on concrete pads.
- Ground Mount Solar Panels: These are ideal for commercial properties like warehouses, factories, and offices. They can also be used to supplement existing rooftop systems.
- Rooftop Solar Panels: These are best suited for large buildings that already have roofs. They can be placed directly on top of the roof, or attached to a building wall.
- Flat Plate Solar Panels: These are designed for off-grid installations. They are usually mounted on poles or walls.
- Hybrid Solar Panels: These combine both flat plates and standard solar panels. They are great for larger projects because they allow you to maximize your investment while still providing a high level of efficiency.
How Do Solar Panels Work?
The process of generating electricity from sunlight is called photovoltaics. Photovoltaic cells convert light directly into electrical energy.
A photovoltaic cell consists of two layers of semiconductors. One layer acts as a p-type material, while the other acts as an n-type material.
When exposed to sunlight, electrons move from the valence Band of one layer to the conduction Band of the other layer.
This creates an electric field across the junction between the two layers. This electric field causes the flow of electrons, creating a voltage.
How Does Harbor Freight Solar Panel System Work?
When you connect your Harbor Freight solar panel system to the grid, it converts DC electricity into AC electricity.
Your house’s power meter then measures how much electricity you use each month.

The amount of electricity you use is compared against the total amount of electricity generated by your solar panels.
Based on this comparison, your utility provider sends you a bill detailing what percentage of the cost of electricity was provided by your solar panels.
When you generate your own electricity using a Harbor Freight solar panel, you reduce your reliance on fossil fuels.
You’ll also benefit from lower monthly electricity costs, which will allow you to put more money towards your mortgage, rent, and other expenses.
It may even make sense to invest in a solar power system if your current electricity rates are higher than average.
What Are The Advantages Of Harbor Freight Solar Panels?
Harbor Freight solar panels come with a range of advantages, and these include:
- Low Initial Cost: As mentioned above, you can get a complete solar panel system for about 2,500. This includes everything from mounting hardware to wiring.
- No Maintenance Required: Unlike traditional solar panels, Harbor Freight solar panels don’t require any ongoing maintenance. All you need to do is simply clean them once every few months.
- Energy Independence: Because Harbor Freight solar panels produce electricity, you won’t have to worry about running out of energy during periods of low supply.
- Environmentally Friendly: Since Harbor Freight solar panels are made from recyclable materials, they help protect our environment.
- Easy To Install: Harbor Freight solar panels are easy to mount and remove. Simply unscrew the bolts and lift off the panels.
- Reliable: Harbor Freight solar panel systems are designed to last for many years. They are built to withstand extreme weather conditions, so you don’t have to worry about them being damaged by strong winds or heavy rain.
Are There Any Downsides Of Solar Panels?
Of course, there are always going to be downsides to using any kind of technology. The biggest downside of solar power is its reliance on the sun.
As mentioned earlier, this makes it difficult to use solar energy during cloudy days.
Also, because solar panels require direct sunlight, they won’t work effectively in areas that don’t receive enough sunlight throughout the year.
Another drawback of solar panels is that they do not store energy. So, if you want to use your battery at night, you will need to invest in an inverter.
However, these drawbacks pale in comparison to the benefits of solar energy.
When you compare the cost of solar panels to the cost of traditional methods of generating electricity, you’ll see that it’s definitely cheaper.
Plus, you can rest assured knowing that your panels will provide clean, renewable energy for generations to come.
Predator 3500 Generator Review | Is It Worth The Money
Quietest RV Generator
The Predator 3500 Inverter Generator is quiet, but how just how quiet is it and are they worth it? We have been using the Harbor Freight Predator 3500 Generator for 2 weeks straight now while Dispersed Camping in Western Montana and have really put it to the test, so lets dive in.
The first thing I am going to tackle is the price. If you have looked in to Inverter Generators at all, you know the are all over the map. The first one I looked at buying was the Honda and it was over 2,300. Having used plenty of Honda products in the fire service, I know their small engines are damn near bullet proof.
2,300 Bucks is a big nut to crack though, so I kept looking. I came across several other brands, and happened to stop in Harbor Freight for some small tools and saw the Predator 3500, and it was listed for 799. After seeing the of the other brands, my first thought was nothing this “cheap” is going to be worth it. But still, for One Third of the price, it piqued my interest enough to do some digging.
Quiet RV Generator
After a few days of diligently searching the internet for the good the bad and the ugly on the Predator 3500, I decided it was indeed worth taking a shot on the “cheap” generator. The price has gone up around 150 since we purchased ours a few months ago, but even in the 950 range, I would buy it again.
The only thing that DOESN’T come in the box is a quart of 10/30 Motor Oil that you need to fill before firing it up for the first time. Every other thing you need comes with this little power house. Included in the box is a small tool kit for attaching the battery to use the starter, a funnel to fill your oil, a spark plug wrench, a small set of “jumper cables” to attach the Predator 3500 right to a battery, and a 30amp Twist Lock to RV Plug adaptor.
Initial Setup
Before its first fire up, you need to fill the oil, which is easy to do through the oil fill access door using the included funnel. The next step is to attach your battery cables to your battery, and you’re ready to go. Total initial setup time was under 5 minutes.
Fuel Up Fire Up
The instruction manual says to use StaBil fuel stabilizer because the ethanol fuel tears up small carburetors, and the StaBil negate the ethanol’s effects, as well as prevent the fuel from turning to jelly if you let the generator sit stored for months with fuel in the tank.
The Predator 3500 boasts a ridiculously long run time of 11 hours on 2.5 gallons of fuel under a 25% load. That seemed like a number that would be a “lab results only” kind of statistic and I couldn’t wait to prove it wrong. We topped off the onboard gas tank, and got a 2.5 gallon gas can and topped it off as well, so we a spare “full tank” of gas on the ready as I was certain there would be no way it would reach 11 hours.
Predator 3500 Generator
Yesterday at 5:00 pm we fired up our Predator 3500 so we could watch TV in the RV and to charge up our batteries for the over night power draw of the fridge, water pump etc. My Wife and I subsequently fell asleep on the couch and never shut it down for the 10:00 pm quiet hour curfew. We also both managed to sleep the entire night until the sun was starting to come up the next morning, which in itself is unheard of.
Thankfully we are Dispersed Camping, and there was absolutely no one else in the area we were camping in, so we weren’t “those guys” with their generator running all night (more on that in a minute)
I opened my eyes about 6:15 am, set up the coffee pot, and hit the power button on my morning autopilot routine. When the little LED turned on and I could smell the Folgers starting to permeate air, I remembered we are boondocking, and I shouldn’t have power right now.
The Predator 3500 was STILL RUNNING 13.25 Hours Later!
Predator 3500 Fuel Efficiency
Now I am not sure how, perhaps the Predator 3500 has a 3 gallon tank but is “rated” as a a 2.5 gallon? I don’t know, either way it was still running. The little gas gauge on the top of the tank said it was dead empty, and then I did something I DO NOT recommend.
I opened the gas cap while it was running to see if there was actually any fuel in it. There was, not much at all, barely a coating on the bottom of the tank, but there was indeed still fuel in it.
I grabbed our spare gas can and refilled the tank, and fired it back up. The Predator 3500 Generator enjoyed less than a 5 minute rest before I fired it right back up, and continued to use it for the rest of the day. It diligently performed as advertised for the entire day, powering our Residential RV Fridge, Two Desktop Computers, a Coffee Pot, One of our 2 AC Units, and our living room TV.
We probably had it pretty close to its 25 amp max for most of the day, as it was a “work” day, where my wife and I were both working on articles for the website, YouTube videos, and downing coffee like there’s no tomorrow. The Predator 3500 just kept on going, without issue.
on that in a minute
Like I mentioned earlier, we both fell asleep on the couch and blew the quiet hour shut down. We both really hate to be “those guys” at a campground, and do everything we can to make sure we are using proper camping etiquette so everyone can have an enjoyable experience on their camping trips.
We got lucky and there was no one else here, but what if their was? I know it’s a super quiet generator, but super quiet in the day time, isn’t the same as at midnight when the ambient noise level is at negative 10. I had to know, how much of an A-Hole would I have been if we had neighbors?
So with coffee in hand, I started walk the campground to see how far the sound of the Predator 3500 Generator running would travel. To my amazement, at the very next camp site, in any direction, it was just about undetectable.
When I say undetectable, I don’t mean that it is 100% silent. I mean to say that you CAN hear it, but you CAN’T tell its one campsite away. It sounds as though Someone, has a generator running Somewhere, way over there.
We have a YouTube video you can watch by clicking here, of when we first bought it and tested it, with real world, unedited volume levels to see what I mean for yourself.
Is It Quiet
The back of the generator where the exhaust comes out is louder than being on any of the other 3 sides. However, since we were on the outer edge of the camping area, the exhaust was pointed away from the rest of the campground. So even if someone had pulled in after we fell asleep, it wouldn’t have prevented them from falling asleep either.
Predator 3500 Generator Cons?
We have been using the Predator 3500 Generator pretty rigorously over the last 2 weeks, and there has only been One Drawback. I can’t even really say its a drawback, more of a personal preference.
The generator comes with a Twist Lock to RV adapter, so you can plug your RV into the 30 amp generator outlet. It is a short adapter, only about 3 inches long, twist lock male on one side, RV female on the other. So, It works.
My only hang up, is that RV Plugs are heavy. So the weight of the RV power cord on the adapter just made me a little uncomfortable. Don’t get me wrong, We used it like that for a few days, without issue, and it never failed or pulled loose, or gave me any real reason to give it a negative on this one, I just didn’t like it.
Our Solution
My solution was to buy a dongle, with a power wire between the twist lock and the RV plug end, so that the weight of the RV plug was on the ground, and not hanging on the adapter on the generator.
Our Unbiased review of the Predator 3500 Generator is 5 out of 5 stars. We have not been paid for a review or endorsement in any way. I would buy it again, even at the higher price point. And one added benefit, is you can daisy chain two of them together and have 50 amp total service should you need too. Even with buying Two of them, you would still be under the price of a single comparable Honda.