RAK Solar enclosure on hot days? Too hot inside?

Hi Guys,

I’ve built a solar node using a RAK Unify enclosure and a Wizblock Starter Kit.
Also inside is the RAK Temp sensor. I’m noticing that when the sun is shinning on the panel the internal temp of the box is getting much higher than maybe it should. I’m worried about the 18650’s that are in there and are they going to be safe when summer comes around?

For example: today it’s 11 degrees C outside but the temp in the enclosure says 29?
I’m concerned about what happens in summer when we get 40 degree days?

The temp sensor is accurate as it is correct the rest of the time. (cloudy days etc…)

I have 1 x 12mm hydrophobic vent installed but maybe I need a couple more?

I was thinking of installing a thermal cut-out on the solar or battery at say 50 degrees (Just to stop it being charged at high temps but will that just mean in summer it stops working altogether? Here a pic…

I’m interested to hear your thoughts?? Cheers!

We have some Solar Nodes outside Here in Germany with BME680 modules and some reached 44°C on the hot Sunny days.
No Hydro vents, Just an electrical Installation Box for outside use.

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Looks good, how are you getting that data?

This is on the iOS App, on Android you can’t at the moment.

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I hope they upgrade that soon!!!

Looks like your panels are shading the enclosure which would help keep it cooler. :+1:

I’m not sure what to do about it…

And If it gets that Sunny and hot, the battery is mostly Not even used.
The battery is charged to about 90%, the charging stops and The RAK is running pure on Solar power, even on clowdy days.
As soon as the battery reaches 85% only then the charging process begins again.

You can try and Tape the enclosure with Heat shielding foil Like the Sheets in a First aid Kit
With the golden and silver Side.

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Yes, I think that might be the go! I think its only the solar panel that creates most of the heat.(being black)

I have a similar node (without a built in solar panel) and it runs much cooler…

I’ll get some tape and test it out.
Here is my build. :wink:

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I would not worry, i also run 2x18650 they can handle a max of 65°C (60°C Recommended) some even more to 70°C.
The RAK 80°C
If it get’s really that hot, the first thing will be the Solarpanel melting :smiley:

The temperature to worry about are blow -20°C, if reached you can end up with just 10% of total capacity or or if it get’s colder the Battery stops working.
So maybe you need Insulation for Winter rather then the Sommer.

I recommend you checking the Weather/Temperature History in your Area.

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Our yearly range here is around 0 - 44 so it should be ok. :+1::slightly_smiling_face:

I’ll still insulate the panel and see it is makes a difference. Cheers!

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Sure make a Faraday cage around your node… Might be ok if you don’t use Bluetooth.

Im not sure what you are saying? A Faraday cage blocks all RF and EMF signals. My problem is heat related.

I’ve added 3 layers of thermal (heat blocking) insulation tape to the back of the solar panel.
Lets see how that goes. I’m sure it’s the back of the panel generating most of the heat… :wink:

We’ve done a lot of work on this in #solar-power on the discord, including using thermal cutoffs and thermal fuses. Join us there.

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Thanks! Is it this page?

One different type we use Here:
It can even Power a heltec v3
A bend Aluminium Plate, Electrical Installation Box seperated by insulating foam.
Also an BME680 Module and everyone can Check the Telemetry Map Marker
Max Temperatur also was about 40-44°C

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Looks good! I like it.
How are you mounting it?

The Electrical Box ist just clamped to the Aluminium Plate, the insulating foam provides a pretty good grip.
The whole construction has no mount, it is placed high on a Mountain, on a small roof of a building. The Donut out of lead keeps it in placed.
It just sits there.
It survived pretty strong storms and heavy rains Up there.
The First months, we ran an heltec V3 and the Panel had no problems keeping it charged.
Now it is a RAK inside.

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Awesome work!! :+1::+1::slightly_smiling_face::slightly_smiling_face::+1::+1:

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I was helped a lot in this reditt chat Reddit - Dive into anything
My node, in a black box, reached 55 C in the sun. I put it up on its final mounting point with the black box covered in a layer of plastic furniture pads covered in tin foil tape () .

https://amzn.eu/d/05k9y1Mt and https://amzn.eu/d/0aDtMN4Ng

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We also have some heat waves here in Germany.
51°C but no problem even for Li-Ion

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