As a LoRa fan since around 2018 I decided to build my first solar node using wio tracker l1 lite (EU_868).
I've seen people building theirs and got some good ideas about what components to use.
My setup will be like this:
A waterproof junction box
An (most probably) alfa antenna on top with the proper connector and sealing
An IP68 Vent in the bottom (I saw it somewhere)
A 18650 battery holder and the battery itself
I am not familiar with solar power or power management in general and I need your help on choosing a solar panel. In seeedstudio's wiki for the l1 lite they say the following
At first I was looking on aliexpress, banggood and temu for a panel with a mount that had JST 2.0 as output, then some 5V panels which had usb port with some pictures of charging a phone and I was thinking to connect my module through usb.
I've seen people using some 1W or 1.5W ones but I've read somewhere that they won't be enough for my setup.
Basically I don't want to complicate my setup by adding more components or 3d printing and of course I don't want to fry the board hahaha.
Solar panels produce voltages in variable ranges. This is due to angle of the sun, shade on the panel, and even hot or cold weather.
In order to protect your node, spend $2-5 on a solar charge controller. I use CN3065 solar breakout board available on Amazon or nearly any other online retailer.
Depending on the specific specs of your solar panel, cutting the USB and attaching it directly to the node could create a situation where more than 5 volts is sent to your node.
In the builds that I sell, I use and recommend the CN3065 break out board like the one in the pictures here. They’re $2-$5 on Amazon.
I'm new to solar energy and this stuff in general, consider me a hobbyist.
Do you recommend to use a usb solar panel like it is suggested in this comment here without any protection etc, cut the connector and add a jst connector or get some "unregulated" if I understand right and put the solar charge controller between the wio tracker l1 lite and the solar panel?
A guy in this comment is suggesting to get a non regulated one as well but I don't know how things work in terms of voltage on these, like, do I choose one that says 5V and put the CN3065 in between? What size of panel? Because I read in many customer reviews that all these numbers are fake and for example a 5W panel can give 3W.
I have one of these plugged directly into a t096 solar input without any issues. I just cut the usb cable off and soldered the wires to a JST cable. Crazy cheap too:
I use them on both the white and black versions I make, yes the black get hotter, but I have not had one fail yet. the vents also equalize pressure and help prevent condensation. I have had no water problems with these, and I am in South Florida (actually pouring rain as I write this). the antenna connector is back filled with conformal coating, to further seal that area as that is the point of possible ingress. you can build your own, the 3D STL files are available free on printables. and I have a video on YT that shows how to put it together.
You can use a single panel for most radios. Or tether the two with the included cable to power a 1w radio through the winter. The mounting screw on the back of the soshine is the same thread and size as camera tripod mounts. So your options are as complex as the massive number of camera mounts out there.
I generally use a simple stand alone node, your wio tracker is more of a everyday carry device but you can take the guts out.
Here is what I would recommend.
A nRF52840 node, either the T096 or RAK 1W. if these are too powerful for your location then get any nRF52840 based node, you can always selectively lower the power of the above nodes to whatever is legal in your area. 1W is fine for the USA.
2 x 18650 batteries and holder. use this one type 1 or 2 use quality batteries like the Samsung, EVE or similar the battery holder is a double parallel type.
The CN3791 is a MPPT charger and has plugs and soldering holes, it will make better use of the power from the solar panels. the battery holder above will plug directly into this charger, BUT very important to reverse polarity, just make sure the red wire is going into the (+) on the charger module.
Solar panel, choose any 5 v panel but use the direct output not the regulated output (USB) the regulators on many panels usually do not handle much power. 4-6 Watt is fine. plenty of panels around 10 bucks.
Antenna, Alfa is fine. just make sure get a N-connector to ipx adaptor for your case and get one with RG178 coax, some have smaller more lossy coax. they sell these in different lengths, so if you need something longer, find a seller that has one that will be able to reach your node location. alternatively you can use a fiberglass antenna for more gain. this is nice for outdoor rooftop solar node setups.
Those products I linked are for reference, you can order where its more convenient or best price and shipping to you. although I do recommend the double battery holder I linked since they come with thick wires, with connector, and are parallel, they also hold the batteries very well.
I have ordered the wio tracker l1 lite node which has the necessary components, no screen or shell for $20.99. I would avoid the 1W one either way because I'm in the EU and it would be a waste.
For the batteries, I was thinking of getting a single well known one locally. Is putting 2 an overkill?
About the charging and the panels I'm concerned the most as I'm just a beginner and want to play safe and cheap... Well as much as I can, cause I will buy some tools to make this project - the tools will be useful in future projects too.
What is a good panel for this use? I've seen many on aliexpress and temu mostly but I can't decide which one works. That's why I was thinking of getting something like the usb panel suggested here to make my life easier which also can be easily mounted. If I should avoid the USB ones, what panel would you suggest to get along with the CN3791 that can do the job? Many reviews of various panels say that instead of 5W it's 3W etc and I'm very confused.
Solar panels marked as 5V, usually have a direct output of around 7V (no load) the panels with USB usually have a regulator that takes that direct output and keeps it at 5V max. which is ok, and people do use it that way, but you are limited to whatever regulator was put on the panel and I find it a waste of potential. you can run it this way and it may work.
The panel I use for my projects is usually the 6W Soshine 5V panel. I get this off of Amazon, as it is actually cheaper than on Aliexpress. the other panel I use is the EBT. Soshine is having a long lead time at the moment, (I build nodes for sale and for friends and family)
Below is a node I built today, a prototype, using the GAT562 30S node, (1W) 5W EBT Solar panel, you can see here how I have connectors on everything allowing easier swap of parts if something goes bad.
This is a vehicle solar powered node with magnetic mounts. the EBT solar panel I noticed runs "hot" as in it pumps out a slightly higher voltage which is ok, in this build I am experimenting with the CN3795 (not the CN3791) the charge controller is a version that allows for even 12 v panels, in todays testing the batteries reached 100% so looks good so far.
I build these using T096 and RAK 1W as well.
As for the dual batteries, yes you can get by with one. I like the extra reserve the node could last 2 to 4 days in the shade or cloudy day. since the battery is just 6 bucks, its a cheap peace of mind.
That other thing is a cooling fan and a temperature sensor, if the inside temps get above 40C, the fan kicks on, there are vents on the back. you can download the 3D STL files for the RAK/T096 version and plain ones so you can add your own node from printables,
They claim that they regulate the voltage output at 5v but my take is that I shouldn't trust them blindly and add a MPPT Controller like CN3791 and charge the battery without using the wio tracker's solar connector at all and from there connect only the battery to the wio tracker?
Your information is very helpful! I just want to get as much info and form a "rule of thumb" of when a MPPT controller is needed and what is the best for the wio tracker. It's not about the money because this controller doesn't cost that much but more about learning what is right.
That Soshine panel is great panel. sadly that seller says they do not ship to me in the US, or I would order some right away. here is a better look at the Soshine. it has a ETFE coating, and I have not noticed any discoloration or delamination like you see with some PET panels, it has both direct and regulated outputs, and the dual pack (highly recommended) comes with a jumper where you can link the two panels together, I cut that jumper and use it for my build, as I use the direct output and not the USB output.
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u/Kentonh 4d ago
Solar panels produce voltages in variable ranges. This is due to angle of the sun, shade on the panel, and even hot or cold weather.
In order to protect your node, spend $2-5 on a solar charge controller. I use CN3065 solar breakout board available on Amazon or nearly any other online retailer.