DIY Solar Phone Charger ($5 Battery Free - UPDATED!)

Picture of DIY Solar Phone Charger ($5 Battery Free - UPDATED!)
Here's a real quick and easy tutorial on making a "Portable Solar Phone Charger", it only took me 5 minutes to make one! It's powered by PURE solar energy. The device is designed to fit right into your pocket, it also comes with a built-in stand! Works with apple devices (tested on iPod Touch and Quadcore Android Phone)

How Does It Work?
Solar powered chargers and powerbanks are pretty common these days. These devices usually have battery reservoirs inside them, to cut it short they are not 100% solar powered so as being eco-friendly. These products are gimmicks, they defeat the purpose of being 100% green and eco-friendly. My DIY tutorial will teach you how to make a "100% PURE Solar Phone Charger". Feel free to be independent from the power grid :D

My Review: (Pure Solar vs. Solar+Battery) 

  100% Pure Solar: (Pros)                           100% Pure Solar: (Cons)
   - 100% eco-friendly                                     - Can only charge devices during day
   - No need for charging internal bat.             - May Not Work with TABLETS (High Amp. Devices)
   - Independent From The Power Grid          - Ideal for outdoor use (where sunlight is present)
Solar Power Bank (w/battery): (Pros)            Solar Power Bank (w/battery): (Cons)
   - Can charge high power devices anywhere    - Conatains Lion Batteries (limited lifespan 1-2 years)
   - Doesn't need sunlight (internal battery)         - Not Completely Eco-friendly
                                                                             - Takes a long time to charge internal battery

Remove these adsRemove these ads by Signing Up

Step 1: Tools & Materials

Picture of Tools & Materials
The links below are just alternatives since the stores where I bought my parts where just available localy in the Philippines. When converted into PHP to USD the price of my spendings would become $5! It's real cheap. The solar panel only cost me $3.

Materials: (Click on the link to see where to buy)
- 6V Mini Solar Panel
- 5V Step-Up/ Inverter USB Charger Circuit ($3
- Your Smartphone (for testing)
- Your Phone's Charger Cable (Interchangable)
- Flexible and Foldable Plastic Card (for stand)

- Hot Glue Gun
- 30W Soldering Iron
- Leatherman Multitool

Step 3:

Picture of
The USB charger circuit came from a cheap old iPod USB charger. The main chip is similar to the well known MAXIM inverter chip. The circuit is a step-up/ step-down regulator, meaning when the power supply is underpowered it tends to boost the voltage but when the power supply is overpowered it limits the output voltage. It's ideal for solar powered purposes.

1st.) Dissemble a 12V High Power USB Charger.
2nd.) Cut the wires, short enough to be mounted on the solar panel.
3rd.) Solder the charger circuit to the solar panel (Adding a switch is optional).
4th.) Use a hot glue gun to mount the charger to the solar panel.
5th.) Be sure that the USB port is not protruding and the circuit should not touch any other leads on the panel.

Step 4: Adding The Foldable Stand (optional)

Picture of Adding The Foldable Stand (optional)
I recycled an old gaming prepaid card and bent it with a ruler. I also hot glued it to the right side of the solar panel.

Step 5: You're Done!

Picture of You're Done!
Now enjoy being completely independent from the power grid. I forgot to tell you that I have an interchangeable USB charger cable for Apple 30 pin, Micro USB, Mini USB, Samsung, Motorola, and Nokia, you can find one in your local dollar store. 

You can now carry your own personal solar powered charger anywhere. It's also a perfect survival kit since sunlight never runs out :)))) Have fun! :D
1-40 of 50Next »
How are you able to use a 12V charging circuit with a 6V solar cell? That doesn't seem to make a lot of sense. Wouldn't it be easier to use a DC to DC boosting circuit instead?
ASCAS (author)  JoshuaZimmerman1 year ago
If your'e familiar with the joule thief, the circuit almost acts just like it except there's a regulator feature.

I was under the impression that 12V car systems were step down regulators, whereas a Joule Thief is a step up converter. Thats why I'm confused.

All the car USB adaptors I've pulled apart have lacked the necessary circuitry to handle voltages lower than 12.

yhdesai1 month ago

i used 7805 and my phone started discharging and it showed charging

do you know if you of these parts could be bought online?

curiouser16 months ago

I am totally new to this stuff :) Can someone please tell me if it is meant to use the disassembled usb circuit or one of the things in the picture on this page? Or I am to somehow use both? Thanks so much for helping me to understand!! :)

playboysbend7 months ago

It doesn't work with my Iphone 4s and my ipod touch...

Mr_Rep7 months ago
My plan is to wire two in series to the guts of a ciragette lighter style car charger since it's got the 5v regulator USB connection. Will this work?
eagletz1018 months ago

Please let me know where did you buy the items locally in the Philippines. I would like to know. Thank you.

Hi, great instructable! question. does the voltage monitor screen turn off or does it constantly stay on? because I would like to just press it if I can and it appears for a few seconds and turns off, to conserve power.

jtagnepis10 months ago
Pre saan ka nakabili ng parts sa pinas sabihin more yung part cost tapos kung Satan more binili ex
Solar Panel P120 cdrking fairview
jtagnepis10 months ago
Pre saan ka nakabili ng parts sa pinas sabihin more yung part cost tapos kung Satan more binili ex
Solar Panel P120 cdrking fairview
pgrferrari10 months ago

Can i also use this solar panel?

cnelson1711 months ago

How long does it take to reach full charge in optimal conditions? Will this also work for android phones? Does the step-up inverter boost charging time?

I didn't realize that my last solar projects were unconsciously inspired by your project of one year ago, indeed I had it in my favorites :-) but I didn't remember that! Well done, awesome project!

I did a very, very simple version of this, by simply gluing a Powerbank to the back of a 4.5 V solar panel. The output from the solar panel goes into the Powerbank, and then when I want to charge something, I unplug the panel from the Powerbank, and plug my device in. However, I feel it's not charging properly, and also, I want to find a way to put a display of the power output on it. Any suggestions?

fbiletta1 year ago
No, I just soldered those two components with wires, as you did
fbiletta1 year ago
Hi, yesterday I connected tis solar panel ( with the first charging module of the step 2.. But it doesn't charge at all my iPod, but the strange things is that my Nokia lumia, when it's connected, show the charging icon on the battery as usual, but it doesn't charge a bit, even after 2 hours. What should I do??
ASCAS (author)  fbiletta1 year ago

Do you have the booster circuit installed?

jerryrard1 year ago
Bilib ako sa pinoy!
stubbsonic1 year ago
I wired two panels in series and got 12.7 V on a fairly sunny day.

I connected the side part of a 12V car charger to the negative on one panel, and the tip of the charger to the positive on the other panel. When I tested the voltage on a USB cord, I got -5V. But ordinarily I think it is supposed to show +5V. Do I need to switch the wires to make this work correctly?
dawelge1 year ago
Are you using a 5v or a 12v? I tried a 5v like in the picture with a 6v 1w 168mA and it will not charge my cell phone. Is there something else that I need?
that is, unless you buy a charger to modify that works with an iPhone
most iphones, if your phone is one, have special circuitry that apple put in that changes the voltage (on the charger end) to a few voltages as soon as a phone goes in, like a code, that the iPhone, iPod, iPad etc, "reads" to ensure its an apple-approved charger
ASCAS (author)  dawelge1 year ago
I'm using a 5v regulator. Do you have a step-up regulator?
ASCAS (author)  dawelge1 year ago
I'm using a 5v regulator. Do you have a step-up regulator?
So the charger circuit you used is a regular dollar-store USB car charger? and if so, you think it will work with this solar panel?
ASCAS (author)  JorgeTristan1 year ago
Yes, but be careful in selecting chargers, I got lucky and I found a maxim based (stepup reg.) Well that device on your link, has enough power to charge USB devices without the regulator.
sbanerjee51 year ago
Hi, I have the same question. I have a 12V - 5V dc-dc car charger. will that work for this. I am not sure if the circuit works if the solar panel puts out a less than 12V voltage.
nickpar201 year ago
For 12v usb charger circuit would a car USB charger work?
That is a darn good question. I happen to have found one and would be interested to know this as well!
mnugnes1 year ago
hi there, i will go to the seeside in one week. i need to build one but i dunno where to buy the 5volt to usb charger circuit.... is there any chance to find it inside one of the emergency battery charger?
ASCAS (author)  mnugnes1 year ago
I updated the guide a while ago, check out step 3. The link if the store is provided.
Free Shipping
Sjoerd X1 year ago
I would like to make a phone charger with batteryfuction, prefered a supercapacitor, to get things working, would the following mod of your project work?:

- Solar panel (6V?) +
|                                              |
|                                              |
|                                              |
| super cap, blocking diode |
|                                              |
|                                              |
|                            switch, for less leaking current when not charging USB
|                                              |
|                                              |
|                                              |
- your "12v" to usb module +
ASCAS (author)  Sjoerd X1 year ago
Yup! But could you draw a schematic of your idea.
Sjoerd X ASCAS1 year ago

U=(1/f) * {I*dt} (capacitor formula)
I = U*f/t (asuming integral {I*dt} = I*t

E=U*U*F= 5.4^2*F
E= U*I*t = 5*1.3*3600 (my battery has 1300mAh, is 1.3 ampere for 3600 seconds/1 hour)


U=voltage, F=capacity, I=current, dt=infinitdecimal time, t=time, E=energy,
ASCAS (author)  Sjoerd X1 year ago
BTW, I updated the guide, there's a link above, of the USB Step-Up Inverter.
No need for formulas, well the capacitors acts as a small-time power line filter. For the Rectifier Diodes, the 1N4007, is a cheap & reliable 1A diode.
iTardis1 year ago
Would I be able to make this without the circuit?
lawroman1 year ago
ASCAS, you left out some important detail. Can you tell us what name brand or model number of that 12V USB Charger ?
akitagawa1 year ago
Hi. Can u pls tell me where to get the charger circuit. If not can u tell me how to know if its the same circuit. Thank you
1-40 of 50Next »