The remote box stopped working a few weeks ago - last voltage log was healthy, weather was fine. I have only today got around to climbing up the hill to investigate. I was expecting to see either theft, vandalism by people or wildlife, weather or water damage. However everything was in place and dry still - but why did it stop transmitting positions? I had taken my electronics toolkit with me, fearing the worst.

Vbat: 3.98

Vin to microcontroller: 1.1v . Oh.

Unplug solar panel to check the output (open circuit), which was a healthy 19/20V.

Plug it back in and hey-presto - healthy output to microcontroller again, and a good ~4V going to the LiPo cell....

Conclusion? The charge controller got its knickers in a twist and locked up somehow. I *think* the battery was receiving charge still given that it was on 3.98, so how come the output to the microcntroller was latched so low?

We shall see how long it lasts. I will start researching alternatives to the sparkfun board and perhaps a watchdog service for the output/auto-disconnect and reconnect the solar panel on reboot...