Costs less than ₹6000
40 watt solar panel – ₹2000
PWM charge controller (5amps) – ₹300
12v 26A battery – ₹3000
LED Strips – ₹25 to 50 per meter
Switching board – DIY
The wiring is simple. You bring a two-wire cable from the solar panel to the PWM & connect it to terminals marked Panel. Similarly, connect a two-wire cable between your 12v lead-acid battery and PWM terminals marked Battery. The Load terminals are connected to the LED switching board. The LED strips are placed in various rooms and connected to the switching board using 2-wire cables.
The PWM charges the battery when the Panel voltage is above 12 volts. It also cuts off supply to Load terminals if it draws too much current or if battery voltage falls below 12 volts.
I let the 26-amps SMF battery charge during the day and leave the LED lights on for the entire night. The LED switch board has its own always-on LED as an indicator. Initially, I had a 7 amps UPS battery. It provided lighting only for a few hours.
I put some plastic cover on them to protect from rain water. Otherwise, it is maintenance free.
On the solar panel terminals, I soldered a diode in reverse polarity to protect the panel from any wiring mistake. The PWM would have its own reverse polarity diodes I suppose.