I’m curious to know, when @richard3366 said “Latest Findings on Device Freezing Issues”, was this somehow interpreted as being a temperature related issue?
If so, the phrase relates to the processor getting stuck - frozen as in not moving, not frozen as in the temperature.
Most commercial electronic components are spec’d to 0 to 70℃ and industrial can do -40 to 85℃. If a circuit is in a box, it tends to be warmer than air temperature as the activity generates heat, so for casual use, commercial components in a relatively well sealed case can do sub-zero temperatures. MCU’s tend to work down to very low temperatures - small thermal mass, they keep themselves warm and no liquids.
Batteries however are a whole different thing and no settings can get around the fact that they are chemistry based with enough liquid / sludge / goo that their power delivery capacity falls off a cliff when they get cold. And whilst you can get power out of a LiPo at -20℃, they shouldn’t be charged until they get back to 0℃ - which in real terms means doing nothing more than sending a message out that says the unit is too cold to do any serious work.
So the min/max temperature settings are about turning off charging for the specific chemistry of the batteries in use so they aren’t damaged (charged whilst too cold) or exploded (charged whilst too hot). The settings can’t make things work because the environment is out of limits.
Insulation &/or some heater element can help, as long as the solar panel can run a heater as well as charge. If the battery case is closed from the elements and insulated, it doesn’t take much to warm up the batteries via solar with a 10W resistor - sometimes even taking power from the batteries themselves if you can juggle the numbers on using battery power to enable the solar to then make up what was used and some more beyond.
Your next challenge at this point is keeping the solar panel clear of ice & snow …
