This is an engrossing DIY project of a simple ‘Solar Powered Cell phone or USB charger’. This solar-powered USB battery charger utilizes to charge many electronic appliances. Moreover, this small circuit can be charge from the PC USB port. For example MP3 players, mobile phones, iPhones, etc.
The circuit is utilizing a solar panel of around 7 volts to 9 volts. It additionally utilizes one diode and four Ni-MH rechargeable batteries. Each battery has 1.25 volt and 2000 mAh charging capacity.
Furthermore, a USB type “B” female port is also connected with the circuit. Therefore, the full charged batteries show 5 volts on the multimeter screen. Thus, this is a perfect voltage for a USB charger.
Hardware Components
| S.no | Components | Value | Qty |
| 1. | Diode | 1N4001 | 1 |
| 2. | Ni-MH Rechargeable batteries | 1.25 volt 2000 mAh | 4 |
| 3. | Solar panel | 7 to 9 Volts | 1 |
| 4. | USB Type ‘B’ Female port | – | 1 |
Circuit Diagram
Circuit Operation
After fabricating the circuit, now check the voltage of your new Ni-MH batteries with your multimeter. Because new batteries are normally 50 to 70 percent charged by their manufacturer. But, if your batteries are not displaying 5 volt. Then charge them for 3 to 4 hours by solar panels. Furthermore, if your batteries are completely discharged. Then charge them for 8 hours if your solar panel output current is 250mA in direct daylight. Otherwise charge them for 10 hours if your solar panel output current is 200mA in direct sunlight.
After this operation, again check your batteries voltage status with your digital multimeter. Now, your batteries will surely indicating 5 to 5.5 volts. Now your DIY solar cell phone or USB charger is completely prepared to charge your devices.
Important Instructions
- Please do not charge your electric appliances when the solar USB charger batteries are charing
- Charge your USB charger batteries first and connect your devices to charge
- Do not overcharge your batteries
- Use solar panels of around 7 to 9 volt and 200 to 250 mA charge capacity
Applications and Uses
It is used to charge:
- Mobile phones
- MP3 players
- iPhone
- Tablets and other electronic devices
