Figure shows a great project / schematic of a 12V solar LED night activated lamp circuit. This is a versatile project and can be used for variety of purposes. For example you can use it as a great automatic solar garden light and this can be done easily by expending each three LEDs in a lamp in
garden by wiring and controlling all these lamps at one place.
By doing this you can control all your garden lights from a single place and also switch on and off all the lights by pressing a button. The circuit is using a lead acid battery which will give a long backup and also an automatic 12V solar battery charger circuit which will automatically shift on trickle charge when the lead acid battery will completely charged. The circuit also contains a dark detecting circuit which will automatically switch on all LEDs at night and switch off in the morning.
You can also use this circuit as an LED night light in your home. For using this circuit in home you can reduce the number of LEDs as desired and make sure to fix the solar panel at the place where it will get the enough light to charge the battery.
The circuit can also be used as a fully automatic LED emergency light inside home or anywhere outside. Moreover you can also use this circuit as an automatic night lamp outside of your home where you feel the requirements of light at night.
You can also increase the number of LEDs in the circuit but make sure to connect the LEDs in same manner as I connected in the circuit, like 3 LEDs with one resistor.
The 1K pot (Potentiometer) is used to increase the charging current for the 12V battery and 50K (VR) variable resistor is used to adjust the amount of light / dark on which you want to switch on and off the LEDs. For 12V battery you can use any 12V lead acid battery of 4.5AH (amphour) or 7AH (amphour).
Use a solar panel which provides 15V to 18V in direct sunlight with the output current of 400mA or more.