This article will show how to build a charger that uses sunlight to charge a 12V battery like the ones in cars or some toys.
Normal chargers need an access but this one uses a solar panel instead which is great for places without electricity.
We will call this charger a Solar Power Battery Charger.
It uses the suns energy to charge batteries in electronic devices like phones, laptops, car batteries even lamps and fans.
These chargers do not plug directly into devices.
They have a battery that stores the solar power like a little juice box.
This stored power is then used to charge your devices through a special part called a capacitor.
Ready to learn how this solar charger works and how to build it?
Let us look forward in this article.
What is a Solar Battery Charger Circuit:
A simple solar battery charger is a device that charges rechargeable batteries by using natural light.
The simple idea is to use a solar panel to collect sunlight and then convert it into electrical energy so that a battery can get charged.
Solar Battery Charger Circuit Diagram:
Parts List:
| Component | Description | Quantity |
|---|---|---|
| Resistors (all 1/4 watt) | ||
| 220Ω | 2 | |
| 680Ω | 2 | |
| Potentiometer | 2k | 1 |
| Capacitors | ||
| Ceramic 0.1µF | 1 | |
| Semiconductors | ||
| Diode | 1N5402 | 1 |
| Schottky Diode | 50V 3A | 1 |
| IC | LM317 | 1 |
| Solar Panel | 18V 1A | 1 |
Circuit Working with Formulas:
The solar panel cell a photovoltaic component converts solar energy into electrical voltage when sunlight strikes it.
A potentiometer and the LM317 integrated circuit is used to control the voltage.
The output voltage is calculated using the following LM317 formula:
Output Voltage Vout = 1.25V × (1 + (R2 / R1))
where:
- Vout is the desired output voltage.
- R1 is the resistance connected to the adjust pin of the LM317.
- R2 is the resistance connected between the output and adjust pins of the LM317.
Reverse Supply Protection:
A Schottky diode with a 3A 50V rating is used to stop a reverse supply.
The diode equation which connects a diodes voltage and current is as follows:
I = Is [V / (enV/n.Vt – 1)]
where:
- I is the diode current.
- Is is the reverse saturation current.
- V is the diode voltage.
- n is the ideality factor which is around 1 for Schottky diodes
- Vt is the thermal voltage approximately 0.026V at room temperature
One can understand and calculate the circuits voltage regulation and current flow with the following formulas that are required.
A 12V power supply with a maximum output is capable of charging many kinds of electrical devices.
Many electrical devices are charged using this voltage.
How to Build:
To build a Simple Solar Battery Charger Circuit follow the below mentioned steps:
- Connect the solar panels positive (+) and negative (-) connections to the LM317 voltage regulators input terminals.
- The voltage generated by the solar panel needs to be more than the required voltage.
- Connect the LM317s output pin to the capacitors positive terminal.
- Connect the capacitors negative end to the batteries negative (-) terminal.
- Wire one of the potentiometers terminals to the LM317s adjust pin.
- Wire the potentiometers other end to the capacitors negative (-) terminal.
- The output voltage is fine tuned using the potentiometers center terminal.
- One can get the resistor values for their desired output voltage using the LM317 formula already given.
- Connect the anode side of the Schottky diode to the positive (+) terminal of the battery.
- Connect the cathode side of the diode to the output terminal of the LM317.
- If required to include a charging indicator add an LED with a current limiting resistor in parallel with the output terminal.
- Secure all components on a breadboard or a printed circuit board PCB.
- To avoid short circuits ensure that every connection is correctly soldered and protected.
- Connect the circuit to the solar panel.
- The solar panel must be placed in direct sunlight.
- The LM317s voltage settings and the output of the solar panels will decide how the circuit charges the battery.
Application and Uses:
The solar battery charger have several uses such as:
Charging devices such as laptops, cell phones and other electronics equipment.
Provide an easy way of charging for passengers particularly when access to standard power sources is limited or unavailable.
Conclusion:
A creative way to collect renewable energy from the sun and convert it into a reliable power supply for charging our daily electronic devices is a simple solar battery charger circuit.
Following these construction details and understanding the process will help anyone to design a useful and sustainable charging solution for their mobile devices.