03/22/2026
Finished my prototype Meshtastic node. After looking around online, I wasn't finding a pre built node or kit that was really designed for the cold winters of NH in mind. With that goal in mind I added some neoprene insulation and stick on heaters. Through the help of a thermal switch the heaters only draw power direct from the solar panel to heat until about 41F where they disconnect leaving all power from the solar panel to fill the 18650 batteries. I did learn however that the Adafruit charging circuit is a bit poor at heat management of it's linear charging chip. If you can keep it cool it will happily pump 1A into the batteries. It seems in even a 70 F house it throttles the charging down. I did add the thermosister to avoid sub freezing charging which can cause lithium batteries to be damaged. I'm going to try adding a heatsink soon but in the cold weather it's actually charging better outside than on the bench. Anyway, I used magnets to stick it on a shipping container for now.
Next version will have the charging chip issues sorted out and probably a bigger battery (not that it should really need it) so I can comfortably put it somewhere higher up and harder to service. Now to find someone who owns a big hill...
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