Make your own Solar Mobile Charger

A solar panel converts solar energy into electrical energy. Solar mobile charger regulates this electrical energy such that it could be used to charge mobile phones. Read this article to know how to make a solar mobile charger at home.

Solar mobile charger

Solar mobile charger is a device which can charge mobile phones using solar radiation. Its major component is a compact solar panel. This solar panel traps solar energy and produces an output voltage. But, since the light radiations falling on the solar panel can vary, the output voltage becomes unstable. For charging a mobile phone, stable voltage is required. So, to make the output voltage stable and regulated, we use a voltage regulator circuit along with the solar panel.

Most of the mobile phones have computer connectivity via USB cable. USB port establishes 4 connection terminals. The connection terminals at the two extreme ends are the supply terminals. In a female USB connector (port via which we plug in USB devices to computer), these terminals carry 5V DC. When a mobile phone is connected to the USB port of a computer, it utilizes this 5V supply to recharge battery. This feature is used in a solar mobile charger. It converts and regulates solar energy to 5V DC and the output will be available through the female USB connector. To this connector, we can easily connect a mobile phone via data cable.

Materials required

1)Solar panel 12V, 4W
2)Voltage regulator IC 7805
3) 100uF, 25V capacitor
4) 10uF, 25V capacitor
5) 100nF capacitor
6) USB female connector
7) PCB
8) Connecting wires
9) Soldering accessories

All these components can be purchased from any electronic spare parts shop or online store.

Let's start building

Solar panel
solar panel
First of all, take the solar panel. On its back side, we can see two connecting wires. One is in red colour and the other is in black. The red wire is the positive terminal and the black wire is the negative terminal. There is nothing much to do with the solar panel.

Voltage regulator
The regulator circuit consists of the following components.

1) IC7805
2) 100uF
3) 10uF
4) 100nF

Circuit diagram

5V Voltage Regulator
Regulator on PCB

Regulator on PCB

Solder all the components on a PCB as shown in the circuit diagram. To test the regulator circuit, connect voltage between 8 V and 18V to the input of voltage regulator. Now, measure the output. The output should be constant and it can be any value between 4.75 V and 5.25V. If so, your circuit is working properly.

Next, we need to connect it to the USB port. This has to be done carefully
USB Female connector

Solder the positive output wire of the voltage regulator to the USB's positive. Similarly, connect the negative output of regulator to the negative of USB. The USB port must be fixed properly to the PCB. Next, connect the solar panel to the input of the voltage regulator (positive of solar panel to positive input of voltage regulator and negative of solar panel to negative input). Once everything is connected, measure the output voltage in open sun light. It should be around 5V. Now, connect your mobile phone and you will see it charging.
Solar Mobile Charger

Once everything is done, fix the circuit properly on a plastic box. The solar panel should face the Sun.

Read LED Solar cell and its working


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Guest Author: A.prabhu das01 Feb 2014

I want 2 do it without any external solar device outside the phone. I want to emerge all the components in the mobile itself no other parts should be exposed. The mobile has to charge when it is exposed to light. Is it possible to do it?

Guest Author: Dave29 Apr 2014

Does it really work? Has anyone ever made a real solar charger himself and successfully used it to charge the mobile phone?

Guest Author: ashwanic08 May 2014

Sir please tell me the specifications of solar panel.

Guest Author: Swapnil03 Jun 2014

Can I connect the battery of cellphone directly to the output terminals of this circuit? If yes, then please tell me the connections.

Guest Author: Austine14 Jun 2014

I am in Abia state of Nigeria. How and where can I can get the solar panel? Please help me get a solar panel so that I can build a solar charger for my phone.

Author: Vineeth V L15 Jun 2014 Member Level: Silver   Points : 2

@ swapnal, battery can be connected directly to the output of the circuit . But this circuit is designed to charge your mobile via a micro usb port. If you need to connect the battery directly then you need an external battery holder and additional circuit.

Author: Vineeth V L15 Jun 2014 Member Level: Silver   Points : 2

Hello Dave, the circuit works fine but the only thing that you need is continuous sunlight for at least 2 hours. The 7805 regulator provides a max current of 500mA which is lower than your charger. So it definitely charges your mobile but duration will be more. Thank you.

Author: Vineeth V L15 Jun 2014 Member Level: Silver   Points : 0

@ ashwanic. The specification for solar panel is 12V 500mA

Guest Author: Laknath20 Jun 2014

What about connecting multi pin charger to usb out put line so that we can use for any charging pin type mobile?

Guest Author: Ch Kashif20 Jun 2014

Yes, my circuit is working properly.

Guest Author: Ch Kashif20 Jun 2014

Please, tell me about the working principel of Solar panel.

Guest Author: Amit21 Jun 2014

Can I make a solar panel at home? If yes then how? Which components are required?

Guest Author: Ch Kashif24 Jun 2014

Yes Amit, you make your own solar panel. Requied components are given above in the project.

Guest Author: Tharun03 Jul 2014

I have 6v solar panel. Can I make it with 6v panel, if else please tell me the components required for 6v panel & circuit diagram.

Author: Vineeth V L04 Jul 2014 Member Level: Silver   Points : 0

@laknath. Yes you can use a multi pin adapter but make sure that you connect it in correct polarity.

Author: Vineeth V L04 Jul 2014 Member Level: Silver   Points : 4

@ Tharun. It is possible but you cannot expect a reliable output from it. The reason is that 6V panel produce 6 volts only when sunlight is at the peak. Normally its output range from 3V to 5V which may not be steady . But in case of a 12V panel the output range is between 6V and 12V so it could be regulated with the help of an ic to get constant 5V. A 6V panel could be used with the help of voltage booster circuit but that requires powerful solar panel (power rating required will be more than that required for a 12V solar panel, at least twice)

Guest Author: Bilal08 Jul 2014

Please help me in creating a 1 A 5 V solar charger and also tell me whether higher current of 1A & 5V damage the battery or motherboard of mobile. Original charger output is 5v and 450mah, the battery capacity is 111o mah. Waiting for your guidance or help me to jump other forums of this type where I can get help from electronic experts. Thanks in advance.

Author: Vineeth V L09 Jul 2014 Member Level: Silver   Points : 4

@ Bilal If your charger rating is 450 mah then using a charger higher than the rated current may damage your motherboard . If you use a high current charger, charging will be faster but it reduces battery life. Low current charging is always advised for good battery life. You can increase the output current by using two 7805 regulator ICs with output connected together and it is recommended to connect the two regulator ICs in the same heat sink close to each other. This is essential because if the heat generated in the regulator is not uniform then any one of the regulator IC will shutdown automatically.

Guest Author: Bilal09 Jul 2014

First of all thanks for previous reply. Please guide me & send a list of voltage regulators specifications and sizes for circuit boards. Please tell me- If regulator converts 12v to 5v, the remaining 7volts will be converted or added to amperes or will be wasted ? Actually what will happen with them? I am beginner in electronics your guidance may help me to sharpen my concept & knowledge .Thanks in advance.

Guest Author: Bilal10 Jul 2014

What output can I aspect from this circuit 5v and how many amp?

Author: Vineeth V L13 Jul 2014 Member Level: Silver   Points : 7

@ Bilal There are lots of regulators available but 78XX series are the best because of its compact size and it requires only few external components. From this circuit you can expect a max current of 500mA that is what the IC specification explains. But you can increase output current to 700mA by providing proper heat sink. Regulator action could be better understood by considering a simple example. Just imagine a big vessel filled with water. If we make a hole at the bottom of the vessel then water coming out will have maximum potential. to reduce the potential the position of the hole could be shifted upwards towards the top. The output current depend on the radius of the hole. The regulator reduce output potential and current to some specified value. The working could be better understood by considering the power dissipation, power input to regulator = Power output + Heat losses. Neglecting heat losses If output power required is 2500mW ( that is 5V * 500mA). Then the regulator Input will be 12V, 208mA. depending on the output load the regulator varies Input current to get output voltage constant.

Author: Ashwin27 Jul 2014 Member Level: Bronze   Points : 0

What changes shall I make to use this circuit for charging other devices? Like trimmer or other small devices which requires more volts to get charged.

Guest Author: Adeel01 Aug 2014

Isn't that circuit take too much time to charge a mobile? I saw on my cell phone charger, it is written that 5V and 2.0A and from this circuit we get 5V and 0.5A. So please guide me about this. I am waiting for your reply.

Author: ian keith07 Aug 2014 Member Level: Bronze   Points : 0

Is there any way that the circuit will stop the flow of current when your mobile is fully charged? What electronic component must be added in order to do it so. Thanks in advance. :)

Guest Author: Harrison Astroff14 Aug 2014

This circuit produces a max of 0.5 A current, a cellphone needs 1A to charge, the phone may show it is charging because the correct 5v is supplied but your battery will not charge.

Guest Author: pratik26 Aug 2014

Why only 100uf, 10uf 100nf capacitors are used?

Guest Author: Dilip Reddy27 Aug 2014

i am having 7.5V Solar Panel will it be sufficient.
Please suggest

Guest Author: Suma Rao24 Sep 2014

Can we make same type of circuit for charging other devices by changing the specification of solar panel? If so, what is the specification for pc?

Guest Author: Mike26 Sep 2014

Hello from Korea! I have found everything on the list but the panel. I did find "4 W 12V / 350 mA ETFE & PVB laminated Triple-junction structure enable 8% PV efficiency". 8% seemed low but I'm not sure since this will be my first electronics project and the voltage is 12 where the required is only 5 steady. In summery, can you recommend a site to get cheap panels that are flexible and durable without the American Labor charge? I don't mind buying 10 or so since this sounds like a fun gift also.

Guest Author: Pogo29 Sep 2014

I don't have a 12v solar panel. Can I use two 6V solar panels instead?

Guest Author: shamsheer10 Oct 2014

How the capacitor values are designed?

Guest Author: Max12 Oct 2014

Is it ok if I use three solar panels with a:
Peak Voltage (Vmp): 2.4V
· Open Circuit Voltage (Voc): 2.75V
· Peak Current (Imp): 400mA
· Short Circuit current (Isc): 440mA
0.96 watts?

Guest Author: Max12 Oct 2014

For the 100nF capacitor, what is the voltage?

Author: Ambrish29 Oct 2014 Member Level: Bronze   Points : 0

Sir according to 12v 4w solar panel design in your circuit, the output current is .34amps but in my charger the output is mentioned as .7amps. Does that cause any problem?

Guest Author: yash17 Nov 2014

Why are Capacitors used here.. I don't understand their Application..
I/P & O/p are both DC Right?

I'm making this For my Class's Mini Project.

Guest Author: Bhaveash06 Dec 2014

I have 7.2V 3W solar panel & I want simple circuit to charge cell phone battery. Please explain circuit shortly.

Guest Author: jedidiah08 Dec 2014

Really great. I did it myself and it works fine.

Guest Author: jedidiah08 Dec 2014

Where can I get the parts in Lagos, Nigeria?

Guest Author: kirtz04 Jan 2015

what if I add a 9V rechargeable battery connected to the solar panel 12V,is it possible or I need another components to complete the circuit? I'm also a beginner. please help, thanks.

Guest Author: atiqah28 Jan 2015

can i use 5W solar panel for this circuit and this circuit doesn't required any diode?

Guest Author: farooq18 Feb 2015

Sir how those capacitors are functioning actually?

Guest Author: ashwini24 Feb 2015

Sir, please tell me the total cost of this project. Can i do this project as a mini project?

Guest Author: manu misra24 Feb 2015

Please tell the reason why we are using only 100uf,10uf,100nf capacitors. Can we use other values of capacitors in voltage regulator. Awaiting for response.

Guest Author: niraj11 Mar 2015

Can I use 12 v 10 watt solar panel for same circuit.

Guest Author: niraj11 Mar 2015

Sir can I use 12 watt v 10 watt solar panel for same circuit.

Guest Author: Md Rubel Rana16 Mar 2015

I'm interested in making this solar mobile charger. Can you tell me how much it will cost to make this one at home myself?

Guest Author: bilaal15 Apr 2015

Won't the absence of a diode drain the phone battery when the sun is out?

Guest Author: yashwant mathe27 Apr 2015

Can the solar mobile charger really work? I am asking because I made it but it does not work so can you give me the possible reasons for it not working?

Guest Author: Thanos29 Apr 2015

I cannot find a solar panel with 4 Watts only, but one with 10 Watts - is it ok to use?

Guest Author: rahul karmakar02 May 2015

Can I use 6v 5w solar instead of 12v? Will it harm the phone or are there any other demerits in using 6v solar panel?

Author: Dharmendrasinh Parmar14 May 2015 Member Level: Bronze   Points : 1

What change we need to get o/p 5v and 1000mA? Which comp is needed for it?

Guest Author: MAX JORDAN27 May 2015

Hey, I am building a solar mobile charger from 6V and 100mA solar cell. Should i follow the same circuit diagram to get output of 5V and 1A. if no, then please suggest me how to do it.

Guest Author: sandeep.s.nair10 Jul 2015

Sir can I use 12V 3W or 12V 5W solar panel instead of 12V 4W?

Guest Author: Arjun27 Sep 2015

Sir, I have 5w,500ma solar panel. How can I make a charger & tell me what things are to be used for it.

Guest Author: Abdullah Bukhari30 Sep 2015

Can I use 12v or 13v battery instead of solar panel to this voltage regulator circuit?

Guest Author: rajesh30 Sep 2015

I connected two 6v solar panel in series, I get 11.6v as output. I connected this to 7805 regulator circuit,I got 5v as output but when I connected my mobile it charges only 3 to 4 second, after connecting my mobile the output voltage of regulator circuit reduced to 4.4v from 5v.
Plz help me

Guest Author: rajesh30 Sep 2015

I connected two 6v solar panel in series and I get 11.6v as output. I connected this to 7805 regulator circuit, wherein I got 5v as output but when I connected my mobile it charges only 3 to 4 second. After connecting my mobile the output voltage of regulator circuit reduced to 4.4v from 5v. Please help me out with this problem.

Guest Author: Michael18 Oct 2015

My solar panel is 3v. Can this work, using the same method?

Author: Kubavat bhargav05 Nov 2015 Member Level: Bronze   Points : 0

What is the price of this circuit? Let me know please.

Guest Author: pranshu agrawal05 Dec 2015

Can I use a solar panel of a calculator?

Author: muzmmils shaikh21 Jan 2016 Member Level: Bronze   Points : 1

Pranshu Agrawal, you cant use a calculator solar panel.

Guest Author: Sandra Peters25 Jan 2016

From which electronic store or website can I purchase this solar panel? Please give guidance.

Guest Author: Aakash P02 Feb 2016

Can I use a wind source of equivalent power (12v) instead of Solar Panel?

Guest Author: animesh09 Feb 2016

My solar panel is 9 Volt 3 Watt. Can this work, using the same circuit?

Author: Gurdeep Singh25 Oct 2016 Member Level: Bronze   Points : 0

Hi, I have semi flexible solar PV , If any one in need I can supply, contact me

Author: Virat Patel08 Jul 2017 Member Level: Bronze   Points : 0

How to connect two 7805 plz explain me. And how to check current. Which current value is good for output.?

Guest Author: James01 Dec 2017

I use solar panels to charge my cellphone and tab. My solar panels are 20v, 2A and 20v, 1A connected in parallel. Output goes to a 2A, 5v regulator circuit and from there to whatever needs charging

Guest Author: Thibeau M.20 Jan 2018

Hello, I have a solar module that has a higher wattage than your 12V 4W module. How can I calculate the components that I need, like you have calculated the 8705 and the capacitors.
I also want to place a buck-boost chopper so I am sure to have a constant output.
I hope you can help me :)

Guest Author: Girish23 Jan 2018

This circuit doesn't work practically.
Theoretically, it's okay, practically found that instead of charging the mobile battery it gets discharged.
Another point observed that, while connecting this Solar Changer (Circuit) to Smart Phone of Battery 3500 Mah, it shows charging.
Please help me.

Guest Author: Alan Jowitt16 Jul 2019

Is there any advantage in putting a diode in series with the panel input?

Guest Author: Emjay17 Nov 2020

Thanks for the information.
So, i have got two 6V 3W solar panels with 500mah each. I would like to know if i should combine them in series which gives me a higher voltage of 12V. With same current of 500mah. I just want to know if it would work like that.

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