So batteries and the circuit dictate the solar cell size there are some of these lights with pr sensors that use a 3 7 volt battery and a solar cell of 4 5 volts.
Solar panel circuit board.
The top countries of suppliers are china taiwan china and hong kong s a r from which the percentage of solar circuit board supply is 98 1 and 1 respectively.
Ic cl0116 lamp controller is an application specific integrated circuit asic in which solar charging and led driving sections are integrated on the chip.
It offers the advantages of low power dissipation low minimum operating voltage and automatic dusk to dawn switching.
For night time switching you may have to use a delay on timer with the circuit.
2 x 1 2 volt batteries at least 3 volt solar cell in full sun.
Two 1n4007 is fine considering the ease of making and the solar panel being 9 v or 12 v plenty of voltage available for the 2 v drop.
1 x 1 2 volt battery at least 1 5 volt solar cell in full sun.
Between the two is a reverse blocking diode.
The lights won t turn on until the solar panel voltage became 1 v or lower that will happen at extreme dusk but not at night.
This one way valve allows current to flow from the solar panel to the battery but does not allow current to flow backwards out of the battery through the solar panel.