I'm planning to use two 6v 0.6W solar panel in series to supply a cheap tp4056 module with builtin cell protection in order to charge a single li-ion battery. In order to regulate the voltage to 5v for the module input I would use a buck converter. Since the module input range is 4.5-5.5v what will happen when in the night the panel voltage drop near 0v? Can the module be damaged? Should I use a cutoff voltage circuit?
It will be as if you connect an LED to a 1 volt power supply,it doesnt damage anything but due to the resistance of the circuit and low output of the solar panel it just doesnt do anything and it can happen whenever the brightness is reduced to that critical point not just nights.i hope it helps.