DIY Solar Panel powered charger

This is a novice guide to build a Solar panel based mobile charger. Recently I built(assembled) a Solar panel based mobile charger, which is pretty decent in performance and gives an output of 5V and 750mA.

All I did is, bought each individual components and soldered/assembled it.

Components Used

Power Source

Obviously the solar panel. A 5W Solar panel available in most of the local electronic shop for less than ₹500, was enough for a decent charging. The size is ~ 30 X 20 cm. Almost a size of a laptop, but it is fine for me, after all, an experimental project for my own use. When kept in the morning sunshine, the output is nearly 4.4W(10V X 440mA).

A Converter

Whatever the output that comes from the solar panel cannot be used to charge the mobile directly. There are 2 options that are available here,

  • A Buck Converter, is to DC as a transformer is to AC. It helps to convert a DC voltage to a desire DC voltage, by increasing/reducing the current, thus maintaining the energy.(When the voltage is stepped up the current will be stepped down and vice-versa)
  • A 78XX Voltage regulator, just reduces the input voltage to XX but maintains the same input current, and the excessive energy will be dissipated as heat.

Since a Buck converter is efficient with close to 90% efficiency, I chose Buck converter. I got this under ₹140. Also there is an adjustment available in this converter, which helps to adjust the output voltage to desired voltage. 

An O/P Interface

My main intention was to have a mobile charger. So I used a USB female, which can be utilized by many other electronic equipments such camera, power bank, etc.

When you keep the female USB in a way, that the metal connectors faces up, out of 4 metal connectors, the right extreme of the USB is Vcc and the left extreme is GND.  Where Vcc is expected to be 5V wrt GND

USB Spec



Required wires and adapter-pair/Connectors. Utility equipment such as Multimeter and a Soldering gun.

Assembling Them

Since everything was readily available, assembling them is the only actual work that I have done. I soldered all the components with adapters so that I can assemble or change any of the components when needed(modular).

And as I assembled all these, I am able to charge my mobile using a data-cable.


Assemebled components


I am getting an output of 5V and 0.8A, which is 4W, from a solar panel delivering 4.4W. So I am getting almost 90% of efficiency.

Daily, I am able to harvest enough energy to charge my 3000mAh mobile battery.