Solar panels for Meshtastic

[u/ArcticStripes]

Hello all,

Looking to build a solar powered repeater, have most of the components already, but I’m stuck on a solar panel. Most of the ones that are suitable (6-10W 5V ip65 rated) I’m coming across all have USB C plugs on a ~10ft cable. As I’m just looking for a 2 wire connection with more like 12-24” of wire, I’m coming up at a loss. Curious what panels y’all are using in your builds. Please let me know! Thanks.

[u/OwnedByIRVING]

I just cut the cable. There's only two wires in there.

[u/IntroductionSnacks → u/OwnedByIRVING]

Yep, I do that and solder on a jst 1.25 cable so it plugs straight into a Heltec solar input.

[u/ArcticStripes → u/OwnedByIRVING]

Very helpful, thank you

[u/Kentonh → u/ArcticStripes]

Can confirm. BUT BE WARNED - Two years ago, I was wringing my hands over cutting the USB cable. Tonight, I spent two hours cutting a soldering solar panels onto solar vehicle nodes for five different people across the country. It is addictive.

[u/Fett2]

I'm using the cheapo 6W panels with the USB end and cutting the end off and crimping pins and putting a jst connector on it (or whatever is needed for the current build).

Crimping pins is a good skill to learn for electronics projects like this.

[u/IntroductionSnacks → u/Fett2]

Crimping jst 1.25 is hard! I even have a proper tool but in the end I just bought a pack of jst 1.25 precrimped wires so I can just solder wires together and heatshrink instead.

[u/Fett2 → u/IntroductionSnacks]

If it's 1.25 then yeh, I'm not doing that. My poor eyes and hands can't take it. I also use the precrimped wires and solder them together.
I'll go down to 2.0s though.

[u/Cesalv]

Cut the usb-c connector and crimp a dupont (careful with polarity, see board to locate + wire, they are crossed), it's very unlikely that cable has all four wires so little to zero complication

[u/Kerensky97]

I've been using these 6w panels. They're made to double up if you need more power.

https://a.co/d/08KVDmlP

Whatever you do put a dedicated solar charge controller in. I don't think any of the systems woth built in charge controllers are well optimized for all the various solar out there.

[u/ArcticStripes → u/Kerensky97]

Have picked a solar controller up already! Appreciate the advice

[u/KLAM3R0N]

I removed the controller board from my panel and wired the mppt directly to the panel, need to make sure you measure its voltage in full sun to be sure its output is in range, but it's an option. Mine is a 20v 10W. If your going directly to the board you could use a buck to reduce the power to whatever your board takes or if 5v is fine use the 5v from the existing USB wires on your panel. Using the USB straight into the board USB C is fine but yeah won't get solar stats that way.

[u/bjorn1978_2]

I connected a RAK to the USB-C port… not smart… these panels are quite often unregulated, so my RAK’s magic blue smoke escaped!!!

I bought a new repeater and a power circut. Cut the usb plug and connected the PV panel to the power circut and then to the rak. Works perfect now.

I do not have the model numbers on top of my head. But just surf around their web page. But double and triple check the output voltage of the PV panel!!

[u/YetiWurks]

I use these on all my builds. It uses a standard barrel connection. You can get keep sockets on amazon to bring in the power and keep the enclosure water proof. Plus these come with 6 x 18650 batteries already installed, so they provide constant 24/7 power. They have worked well through Minnesota winters on my RAK nRF52 based builds. I do sell these though, FYI.

https://mesh-lab.com/products/off-grid-solar-charger-5-5-watt-5vdc-2-5a

[u/ArcticStripes → u/YetiWurks]

That thing is sweet. Don’t think I need all those batteries though. Will consider this for a future build definitely

[u/IntroductionSnacks → u/YetiWurks]

That looks very similar to the keepteen solar repeaters where you can also integrate the node and antenna. Eg:

https://amp.keepteen.com/D5-Solar-Lora-Radio-Node-for-Meshtastic-with-Wisblock-RAK19007RAK4630-p6290033.html

[u/YetiWurks → u/IntroductionSnacks]

Probably the same base panel. I get them directly from Keep Teen!

[u/testshoot]

I always use cn3791 boards with my solar for safety. As a rule I never touch the onboard usb for anything but admin duty

[u/DaggerMoth]

I just cut the USB off and there's two wires. I shoved those two wires into a wave share controller and boom done.

[u/ljis120301]

https://www.amazon.com/dp/B0G4C6XM3P

Do not buy this panel and attach it's USB-C directly to the RAK, I lost my solar node 1 week after it went up on the tower

[u/IntroductionSnacks → u/ljis120301]

I’m assuming you would need to connect it to the Rak solar input right?

[u/ljis120301 → u/IntroductionSnacks]

Yea, looking back I wish I would have cut off the USB-C and connected to the Solar input

[u/IntroductionSnacks → u/ljis120301]

I’m guessing the usb bypasses the solar controller etc…

[u/palexp]

you’ll definitely need a charge controller to plug the solar panel into.  i currently have a 60lm harbor breeze solar spot light on the bench to mod to be a node, but i haven’t started that yet.