Picture of Lithium Heavy Duty Solar USB Charger 2.0

Sometimes you need a whole lot of solar power to get your gadgets going. Bigger phones, tablets, and gadgets mean that they're more power hungry. When normal DIY solar chargers fail you, you need to turn to a Heavy Duty solution.

In this project I'm going to show you how to create a Lithium Heavy Duty Solar USB Charger. It's the second version of this project and addresses a lot of minor issues while improving the overall design. The key highlights of this project are it's 5W Solar Panel, 3A dual USB output, a powerful Lithium Ion Battery, and a laser cut wooden case.

Due to the parts being used, this project is suitable for direct solar to USB charging and could easily be used day to day. It's something that could be used for light camping or be used in an emergency situation. It's internal battery is more than powerful enough to charge any cell phone up at least once, and lesser phones/ gadgets several times. The only downside to this project is that the laser cut case is not waterproof, though it is very rustic looking.

Most of these parts can easily be found online, or at least very similar parts. I have a full Lithium Heavy Duty 2.0 Kit available on my website. If you're looking for a smaller project, try the Solar USB Charger 2.0 Kit. If you just want something pre made, then grab a Folding USB Solar Cell.

Note: This is not a beginner Maker project. Lithium Batteries can be dangerous. Practice doing some other projects before doing this one.

Difficulty: Easy - Medium
Cost: Medium - Less than a store bought at the same power
Time: 30 - 60 Minutes

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lnguyen298 months ago

Thanks for the educational ible! Very inspiring. I was wondering if a 7.5V 720mA solar cell is compatible with the lithium charge controller on your website? Is that too high of a voltage for the controller? Or is there such a thing? Also, I've read all your other ibles and have noticed that the rechargeable AA battery solar chargers require a diode between the solar cell and batteries, does the charge controller also eliminate the need for this? Any help would be great! I intend on helping a brown dog get some treats ;)

JoshuaZimmerman (author)  lnguyen296 days ago

Yes. That would be enough. You may want to drop the voltage down a bit though. (I've had people use 9V solar panels with the lithium boards I sell, no problems. It's one of those "it should be ok, but I should also just monitor it a bit to be sure" kind of situations.)

There already is a diode built into the charge controller I'm using, otherwise you are correct about one being needed.

digdug181 year ago
How is this an instructable, you don't teach anything about making the actual product. It's just free advertising for you to sell a product....

Now if you included how to make all your actual circuits.
JoshuaZimmerman (author)  digdug181 year ago
I also don't tell you how to forge your own screws, cut down and mill trees into wood, how to chemically treat copper and turn it into a solar cell, or how to spin copper into wire. But no doubt you find fault in all instructable posts for those reasons as well.

You can use this basic guide to create your own charger using a whole bunch of off the shelf parts. If you really want to learn how to make your own using similar parts found all over the web, or use parts of this design and go your own direction with it. No one is forcing you to buy anything from me, and I'm giving you the design and explanation for free. (In fact if you have access to a whole lot of junk, like at a Makerspace, you could use this design and make it from junk parts alone.)

That said, it would be nice to have the schematic for the charge controller so those adventuresome enough can beild their own from scratch.

JoshuaZimmerman (author)  haroun6 days ago

It's not THAT kind of project. Building the charge controller from scratch and the USB circuit from scratch are rather large under taking. In fact that would increase the difficulty and price by a factor of 100. That isn't the point of this project. This project is for beginners. If you're smart enough and ambitious enough to make your own USB and charge controller, you're smart enough to do some quick google searching and easily find schematics for both. I've had great success doing this with middle and high school students, none of whom would have been able to make this 100% from scratch. They were however able to make up this project and could easily explain the theory and ideas behind it. That's the point of this.

SparkySolar2 months ago

Thank you

kayra9 months ago
can you send the circuit diagram and how can we connect the solar panels each other
Poetic197910 months ago

a cigar box works very well for this step. That's what I used:)

mterpstra11 months ago
I have noticed JoshuaZimmerman that you didnt specify the type of lithium... I want to make one that has lots of mAh and that will support my samsung galaxy mega ( lots of power drawn) and my ipod classic and my gfnds samsung note. Can I use any type of lithium?
Tampaguy1 year ago
I have used Lithium Ion Batteries for years with Radio Controlled aircraft. Yes, they need to be handled with care, but I would never consider them any more "Dangerous" than any other type of battery - Why do you say they can be Dangerous?
There are two concerns with Lithium batteries. First they are prone to thermal runaway; and second, the electrolyte is flammable. Couple that to the fact that lithium packs a lot more energy in a small space than any other battery technology and you have a dangerous combination.
Many RC enthusiasts will only charge their lithium batteries in a protective sack that can contain the results if a battery does go rogue.
Lithium batteries have become safer as manufacturers have improved their designs and processes. That combined with protective circuits that prevent over-charging of the batteries make the incidence of battery mishaps rare. but while the probability of a problem is low the consequences are significant.
Like any of the "new" advances in science, there are positive and negative qualities. Personally, I'm not into learning all the nuances of the MANY TYPES of chemicals used on Li-Ion batteries. Some are safe, some are DANGEROUS. The best information on current technology, and how these batteries came to be.

Complete info can be found at http://www. - Thanks for pointing out some of the possible dangers!
lithium, batteries have an unseen floor, they catch fire and their flame is invisible to the naked eye,by the time 80% of damage has taken place no appearance is seen.
Electric scooters have been retrofitted with other batteries for this reason the rider does not know he/she is on fire. (First noticeable cases IBM laptops-since changed.)
They don't catch fire until the casing is breached. Without oxidizer, there is no fire. What happens is called a thermal cascade, and it is when the heat from the battery accelerates its own discharge in a positive feedback loop. At some point in the cycle heat swelling can rupture the battery and spray lithium into the air. That is when it catches fire. Before then, it is just irreparable damage.
Wow! I am vey impressed with the high level of knowledge on these batteries - I guess I lived in my little corner of the world (R/C airplanes), and had no clue as to many of the facts pouted out in other replies. Thanks to all who replied for the information!
I'd like to build something like this, but I want to permanently attach the solar cell to the battery instead of plugging and unplugging it. Are there charge controllers available that would allow this.?
JoshuaZimmerman (author)  ShortnBearded1 year ago
That there are. Quite a few. I have one on my website if you can't find one.
Onfire12991 year ago
Thanks :) I will look that up ;)
Onfire12991 year ago
Awesome instructable!!!! =) I am actually planning to make something similar to this, but I'm using a battery from an old ipod, and its not gonna be solar.
But I did a lot of research, and I still can't figure out how to tell if the battery is charging (the battery has full charge right now, last time it worked), and I think you might have more experience than I do, so maybe you would be able to help me somehow...
JoshuaZimmerman (author)  Onfire12991 year ago
You need a battery charge controller. Many have built in battery status LEDs. I have a couple different types on my website, some with many status LEDs, and some that just tell you when it's full. It depends on how big you want your project to get.