Hello,
So after some time away I have finally taken up my electronics hobby again
I came across this (old) post by Felix describing a setup where the moteino + WeatherShield is powered from a supercap only, and using a small solar panel to replenish energy during the day:
https://lowpowerlab.com/2017/09/15/weathershield-supercapacitor-tiny-solar-cell/I decided to copy this setup using a Moteino R4, the r2 WeatherShield, a 5.4V 7.5F supercap and a 6V/1W solar panel. Now after a lot fiddling with ATC and such I got everything working. The moteino wakes up every two minutes, does a reading and send the payload, no ack requests/retries. This works beautifully...but indoors only.
Running everything indoors at regular room temperature and I see the cap voltage drop ~0.5V over 24hrs with no or very little light hitting the panel. Remarkable. As soon as I put everything out in the cold (~ 0C / 32F) I'm lucky to get two packets through. The voltage on the cap plummets and that's the end of it. After half an hour the cap is at ~2.5V. I have no clue as to why that is, so I would be very grateful if anyone can help understand what could possibly be going on here.
Thanks.