For the next revision of the SunControl board it would be nice to be able to selectively switch off the charging circuit. Here's the rationale behind the request:
Scenario 1: Battery not fully charged, temperature in permitted charge range (32F to 113F): The output can be powered either by the battery, by the solar energy, or a combination of both. If the solar energy exceeds the output and waste wattage, the remaining energy is used to charge the battery. (covered by current design)
Scenario 2: Battery fully charged, temperature in permitted charge range: The output is powered by the solar energy. The charging circuit is off, the remaining energy is dumped through the board or an external heat sink. (covered by current design)
Scenario 3: Temperature not in permitted charge range. The output is powered by the battery, the solar energy, or a combination of both. If the solar energy exceeds the output wattage, the battery does not contribute and does not get charged, and the remaining solar energy is dumped through the board or an external heat sink. (NOT covered by the current design)
Ideally it would be nice to be able to selectively switch off the solar input, the charging circuit and the output separately. I don't think it would make sense to allow switching off the battery. The discharge circuit should stay on as is (even if pushed aside if sufficient solar power is available). The permitted discharge temperature range is quite a bit wider than the permitted charge temperature range.
If using a thermistor to define the permitted charge range there should ideally be an option to calibrate the thermistor for both low and high limits.