I used TP4056 lithium ion battery charging board on this Solar Night Lamp project with Auto On/Off.
There are two types of TP4056 board, one with battery protection, the other doesn't have. I used the board with battery protection.
I hacked the TP4056 board in such a way that the built in protection circuit becomes auto on/off switch by putting jumper wire on Pin 5 of 8205 MOSFET to the blocking diode towards negative output of the solar panel. So when there is sunlight received by Solar panel, pin5 of 8205 mosfet is negative which turning the LED light Off. When there is no sunlight being received by solar panel, the pin5 will be pulled up to postive voltage by the internal resistance of the board itself, turning the 8205 MOSFET on and the LED light on.
I used 6V/3.5W (0.54Amps) solar panel, 3 pcs 1W LED with 5Ohms/2W in series limiting the current to 0.20Amps total. This is enough that the light lasts overnight. Doubling the battery is preferred as the LED light will consumed around 2.4Ah of capacity of the battery. Solar panel will harvest energy around 2.9Ah assuming of 5 hours full sunlight exposure of the solar panel.
PS: In case that auto on/off function did not work, add a 1N4001 (1Amp/50V) diode in series with the solar panel to the input of TP4056 board. You can connect either on the negative or positive side of the solar panel.
Happy DIY
