Introduction
A Solar Battery Charger is a system that uses solar energy to charge batteries. It converts sunlight into electrical energy using a solar panel and stores the energy in a battery for later use. This project promotes the use of renewable energy and reduces dependency on conventional power sources.
Solar chargers are widely used in rural areas, portable devices, and renewable energy systems.
Objective of the Project
- To charge a battery using solar energy.
- To understand solar power generation.
- To regulate charging voltage and current.
- To prevent battery overcharging.
Working Principle
The Solar Battery Charger works on the principle of photovoltaic energy conversion.
How It Works
- Solar panel converts sunlight into DC electrical power.
- The generated voltage is regulated.
- Battery stores the regulated power.
- Charging stops when battery reaches full charge.
Components Required
- Solar Panel (6V / 9V)
- Rechargeable Battery (6V / 12V)
- Diode (1N5819 / 1N4007)
- Voltage Regulator (LM7805 / LM7812)
- Capacitors
- LED Indicators
- Resistors
- Jumper Wires
- Breadboard / PCB
Circuit Diagram (Basic Solar Charger)
Connections
Solar Panel + -> Diode -> Voltage Regulator -> Battery +
Solar Panel - -----------------------------> Battery -
LED Indicator connected with resistor across battery
Arduino-Based Solar Battery Charger (Optional Smart Version)
Additional Components
- Arduino Uno
- Voltage Sensor Module
- Relay Module
- LCD Display
Arduino Code for Solar Battery Charger
int batteryPin = A0;
int relayPin = 8;
float batteryVoltage;
void setup() {
pinMode(relayPin, OUTPUT);
Serial.begin(9600);
}
void loop() {
batteryVoltage = analogRead(batteryPin) * (5.0 / 1023.0) * 4;
Serial.print("Battery Voltage: ");
Serial.println(batteryVoltage);
if (batteryVoltage < 12.6) {
digitalWrite(relayPin, HIGH); // Charging ON
} else {
digitalWrite(relayPin, LOW); // Charging OFF
}
delay(1000);
}
Code Explanation
- Arduino reads battery voltage.
- Voltage is monitored continuously.
- Relay disconnects charging when battery is full.
- Prevents overcharging.
Advantages
- Renewable energy based
- Low running cost
- Environment friendly
- Useful in power failure areas
Applications
- Solar lanterns
- Solar street lights
- Portable power banks
- Rural electrification
Future Enhancements
- MPPT charge controller
- IoT monitoring
- Mobile app integration
- High-efficiency panels
Conclusion
The Solar Battery Charger is an eco-friendly and practical electronics project that demonstrates renewable energy usage. It is ideal for students learning power electronics and sustainable energy systems.
