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FlexSolar 40W Solar Charger Tested And Reviewed

Disclaimer: This product was sent to us for free in exchange for a review. That does not affect our opinion about the product, in this article we list both what we like and dislike. Read more about this here.

The FlexSolar 40W Is A Rugged Solar Panel That Fits In A Backpack

Today I will be reviewing the FlexSolar 40W solar charger, which is a portable and foldable panel for people on the go.

By folding it five times it goes from 48.8 to 11.1 inches, and it’s one of the most powerful foldable panels like this I have ever tested.

flexsolar 40w solar charger

View on Flexsolarenergy.com

View on Amazon.com

So who is it for? Well, in my opinion it’s best suited for the person on the go that is looking for a very portable panel with a powerful USB C port.

It’s capable of charging devices that can be charged with USB cables, and things like power stations that can be charged via a DC port.

Let’s start by taking a look at the features, before I share my opinions on it.


The Solar Panel

The 40W panel is made up out of six smaller panels.

These smaller panels are highly efficient monocrystalline panels, with a layer of waterproof fabric. The top ETFE layer protects the panels and makes it resistant to dust, dirt, and water.

flexsolar panel unfolded and being held by jenni

It’s all molded together to ensure a water-and dust-proof product.

There are four holes, one in each corner of the panel when it’s unfolded, that make it easy to hang the panel with the included carabiners.

Ports And Connections

The junction box has three ports.

One USB C rated for up to 40W, suitable for phones, tablets, and notebooks that can charge via a USB C cable.

One USB A, which supports QC3.0 charging and up to 18W output.

One 5.5mm DC output, which makes it possible to charge power stations and other batteries with the right cable.

Note that no cables are included to charge power stations.

FlexSolar does sell a 5.5×2.1mm cable (click to view on Amazon) that can be used to charge your power station if it has an DC5521 input.

IP67 Rating

An IP67 rating is one of the highest ratings possible when it comes to how protected the product is against water and dust.

For example, with this rating the panel is supposed to be able to handle being in the same bag as small tools without taking damage, and handle short periods of immersion in water.

I do not recommend putting the junction box in water even though it has the IP67 rating.

In The Box

FlexSolar includes two carabiners with the panel. Note that no cables are included.

Size And Weight

The panel measures 48.8 by 11.1  by 0.1 inches when unfolded, and 8.0 by 11.1 by 1.8 inches when folded.

It weighs 2.86 pounds (1300g).

jenni holding the folded flexsolar panel


Alright, now we know what the specifications are, but does it live up to it? Here are the things that I like and don’t like as much about the FlexSolar 40W panel.

What I Like

Powerful for its size

As I mentioned earlier, there are not a panels this portable with a 40W output rating.

If you’re traveling with a phone, headphones, and a notebook that can charge via USB C, this would be great panel to travel with.

FlexSolar advertises it as a rugged panel that will fit in your backpack bag, and I agree that it’s portable enough to bring with you in a small bag.

solar charger on the rocks

If you’re a backpacker heading on a long hike it might still be a bit too heavy, and I only recommend going with this model if you absolutely need the full 40W.

In my tests, the ports were able to output what they’re rated for. My MacBook recognized it as a 40W charger, and when I connected it to a power station it was producing around 30-35W.

The Ports

Even though I would’ve liked to see a couple of included cables and adapters (more about that down below), I like that there are three different ports.

They’re all useful to me, and they’re all as powerful as they can be.


I like that it doesn’t use fabric that will suck up water and stay wet.

If it gets wet, it quickly dries and you don’t have to worry about it being damaged in any way. Due to this, it’s easy to wipe it off with a wet cloth if it gets dirty.

thin flexsolar panel
The Flexsolar 40W panels are extremely thin.

What I Don’t Like

No cables included

I would’ve liked to see a 5.5×2.1mm cable included and a couple of DC adapters so you could connect it to the most common power station inputs.

Most similar panels that do have a DC output do usually come with at least a 5.5×2.1/2.5mm and 8mm connectors.

No way to secure the panels when folded

While it’s great that the panel folds together and becomes a very portable package, there is no velcro or magnets that keep it folded together.

This won’t be a problem in most bags, but when I was carrying this panel around it sometimes unfolded itself because of the way I was holding it.

Another way to keep it folded and protected would’ve been to include a case for it, that would also make it easier to pack.


The FlexSolar 40W solar panel charger is a great choice for travelers, but it would also make a great backup panel to keep at home.

I am going to keep bringing this panel on camping trips, because it can charge all the devices I bring with me.

The biggest reason it’s my choice when heading out on a short camping trip is that it feels like it can handle it, and I won’t have to worry about it getting too moist or dirty to be functional.

All in all, I recommend the product even though it’s not complete right out of the box.

How Do I Connect It To My Power Station?

The answer is going to be that it depends on which power station you have.

Basically, you need a 5.5×2.1mm adapter to whatever the input is on your power station.

If you can’t find one, you can start by getting the FlexSolar DC5521 cable (click to view on Amazon) and then get a small adapter.

Let me know if you’re having issues connecting it to your specific battery and I’ll do my best to help you out.

Please leave a comment down below if you have any questions.

by Jesse
Jesse has always had an interest in camping, technology, and the outdoors. Who knew that growing up in a small town in Sweden with endless forests and lakes would do that to you?

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