Solar Altoids iPhone/ iPod Charger

I love my iPhone 4 to death.  I really do.  Even if it sucks juice faster than a 1st grader at snack time and I often find myself on low power with a long train ride ahead of me.

I originally made my Altoids USB Charger to use with my iPhone, only to find that Apple being Apple doesn't let it's products play nice with generic USB chargers.  I then set out on a long journey to find a cheap charger that would work with an iPhone 4.  After sacrificing many a cheap Chinese charger to my garbage can I eventually found a great little circuit with the added bonus of having a retractable cable.

It's a cheap and easy project to put together and a great gift to give.

(If you want a USB version of this kit, I have an Instructable for that.  I also published a Heavy Duty USB Version as well which is a beast; for people who need a lot of power on the go.)

Time: 30-60 minutes
Cost: Under $20
Difficulty: Easy

Step 1 What You Need

Parts:
Charging Circuit
2x AA Battery Holder
2x Rechargeable Batteries
1N914 Blocking Diode
Solar Cell greater than 4V
Stranded Wire
Tape

Optional:
Altoids Tin

Tools:
Soldering Iron
Solder
Hot Glue Gun
Wire Strippers
Protective Goggles

If you're interested in this project I have kits available on my website, browndoggadgets.com, that have everything you need to make the charger.  If you're not one for making things I  sell premade chargers as well. 

More than 12% of all profits go to dog and kitty toys.  You wouldn't make a kitty cry, would you?

Comments

[RelientOwl]

Do you have any idea of how to identify a solar panels Volts and Amps?

[DoctorDv]

What is the difference between this charger and your other solar USB charger?
-Doctordv

[rcisneros]

I hate to tell you, but I've tested dozens of batteries brands. Literally. And almost none of them come close to their rated mAh.

Most no name recharagables are 50% at most.

Second tier, what I call name brand generics like Tenergy, yield around 75%+. (They have several lines and I have NOT tested the ones pictured.) Problem with these types is that the ones that test higher tend to drain faster that higher quality batts.

Name brands tend to be in the 90-99%+ range. Rayovac, Energizer, Duracell, etc.

The kings are the Sanyo and Sony Cycle batteries. They test at 100% and the the results are exactly the same for each battery.

-Bottom line is there is NO such thing as a 3000mAh battery as far as I know.

[Roosi80]

-Bottom line is there is NO such thing as a 3000mAh battery as far as I know.

Yeah, but there are 2850 mAh batteries like the ones in the pics.

[rcisneros]

Yeah you missed the point. I can post pictures of batts that are labeled 3000mAh. That doesn't make them 3000. If you had a decent tester you could check it yourself.
If you tested the ones in the pictures, I really doubt you'd get near that number. Good luck with it though.

[Da Person who plays paintball.]

What the author meant was that with two batteries he can get 3000, not one has 3000, and with two sets he could get 4000-5000.

[inquilab]

Hi Joshua- How would i go about building this device but for 3x 4x or 6x AAA batteries instead of 2x AA batteries? Appreciate your help.

[inquilab]

Okay, so I'm a newbie, but wondering if all i'd need to do is buy this device:

http://www.aliexpress.com/product-fm/536521891-free-shipping-emergency-charger-AAA-battery-external-backup-battery-charger-for-iPhone-4S-4-3G-3GS-wholesalers.html

and then connect a 3.6 volt solar panel directly to the leads on battery case within this device (with a diode on the + side)

Would that work- charging my three AAA batteries from solar panel, while simultaneously also using these AAA batteries to provide a charge to my Iphone?

[JoshuaZimmerman]

I really have no idea without taking on apart and seeing how it works.

It looks like it uses a boosting circuit of some kind, as 3 AAA rechargeables does not equal 5V, and a Li-ion would only be 3.7V.

Now you could, in theory, hook up a solar panel to it if it is just a boost circuit. However, you'd want to use something far larger than a 3.6V solar cell as a 3.6V solar cell will NEVER give you 3.6V. You'd want something larger than 5V with at least 200mA of current available.

Plus having batteries is a really good idea. Solar is not consistent, and batteries or a big capacitor helps regulate the flow of power.

Man, now I'm going to have to find one of these and take it apart!

[blinkyblinky]

Will the circuit boost enough to charge an iPad? I read my adapter and it says 10 watts.

[JoshuaZimmerman]

You know, the older iPads seem to work just fine, I've gotten reports that the newest iPads have issues. As I don't have a new iPad, nor do I know anyone who does, I have no way of testing.

[NanoRobotGeek]

I thought you needed 5 volts to charge an "i device". will it work the same with 2.4 volts or will it be slower?

[JoshuaZimmerman]

The circuit boost the voltage up to 5. Thus why we can use 2 AAs.

[NanoRobotGeek]

Oh... right. thanks i get it now

[xxhydrax]

SOMEONE PLEASE HELP ME WITH THIS:

Ok, first let me start off by saying I am very very new to electronics and have absolutely no idea what some of these components. None the less, I still want to build this thing. Now I have 2 AA rechargeable batteries, the blocking diode (which I don't know how to install) and pretty much everything else on the list, EXCEPT 1 THING; the charging circuit. Since I said before I have no experience, I was wondering how I can get/make this circuit. Is their a detailed instruction on exactly how to do this? PLEASE help me.

[wchiong]

As what you say we can't get a iPhone to charge directly from the sun , then why do we put in a solar cell ?

[Da Person who plays paintball.]

Because the solar cell charges the batteries, which then charges the iPod or iPhone

[wchiong]

okay understood ! But how long will the it charge from 0% to 100% ?

[nireves1]

Hi Joshua
Thank you for this nice instructable!
its awesome
i was wondering if there is a limit to the voltage of the solar panel used?
could i for example use a 9volt 109mA solar panel?
and what kind of solar panel do you think would charge the AA's the fastest with the least amount of light without adding extra parts (except perhaps a diode or voltage regulator) to the circuit?
Thank you very much!
Sev
Amsterdam/Berlin

[iApple guy]

I was reading the comments to see if anyone has already posted this question and it seems that you get cheap Chinese chargers. Do you know where I can get these for a very low price. I do not care if it is in store or online, all I want to know is where I can get a charger circut. A schematic is acceptable as well too make a charger.

[kerec6]

I have a question. A little while ago I bought this as a kit and made it. I charged the batteries and of course, I get the error message. I tried it with standard AA's, and got the same message. The thing is, it still charges, but very slowly. This happens with my friend's iPad when you plug it in to his old computer and it still charges. Is this normal??

[JoshuaZimmerman]

Charge the batteries up first, if you have a 3GS they're insanely picky.

[kerec6]

I did charge the batteries- they've been in the sun for about a week now. I'm using an iPhone 4. And like I said, it still charges but it displays the error message.

[Wehrdo]

I received your kit as a Christmas present, and was pretty excited, because I had considered making a solar USB charger myself. As I was going through the instructions before I started, I realized it wasn't supplied with a diode. :( No sweat though, as I whipped out my electronics box and took one from my stash. I was eager to see the charger in action, so I put a couple brand new AAs in the holder and temporarily connected them to the power pins on the charging circuit. Then an "Oh-No" moment. A "Charging is not supported with this accessory" error popped up on my 3rd gen iPod Touch.

Are these chargers not compatible with that version of iPod? It seems to work with the other iDevice in my house, a 3rd gen iPod Nano.

[Wehrdo]

I forgot to mention my charging circuit has a slightly different PCB layout than the one in your picture. Don't know if that's a good or bad thing.

[JoshuaZimmerman]

No diode? How odd. Sorry about that.

If you're getting that error you just need to charge up the batteries. That almost always fixes that issue.

[Wehrdo]

Turns out I put the diode with a different electronics kit. Silly me ; )

I've tried it with brand new alkaline AAs, which should have a higher voltage than fully charged NiMh, and it still gives me that error. Any other suggestions?

[mrsayao]

What's the difference between this circuit and the one that charges non-apple phones?

[JoshuaZimmerman]

Apple stuff, unlike every other USB device on the planet, checks the USB data ports to see what it's connected to. Thus it takes in more power if plugged into a wall as compared to a computer USB port. Well this causes some issues as up until that point no USB charger on the planet had power flowing to the data ports.

This is why a lot of people will plug their new iPhone into a newish USB charger and get an error message and no charging.

I have some some USB charger circuits that work with iPhones, but I can't always get them. Which is why I have a circuit specifically for iPhones and a generic USB one that may or may not work with an iPhone (though these days most of the ones I get in seem to work just fine).

Also, having a built in iPhone cable is a nice touch.

[me the great]

Will any iphone charging cord work or do you have to use a cord like what you have? A, B, or both?

[forgotengun]

im not trying to spam or be offensive, but if your looking for a minimaly priced solar ipod charger. this would suffice it costs around $6. I bought them before and can verify that they work, although the battery only holds about half an ipod charge.  <img src="http://www.budgetgadgets.com/images/proimages/708/7088/DSC_32990_360.jpg">

[JoshuaZimmerman]

Yeah, I've tested those as well. They do work, but you can build better for a little bit more. With the ones I build you can always swap out batteries if they're dead, or if they degrade over time. You can always build in a better charger with a larger cell and battery capacity.

It all depends on what you want to do.

[tmaxfield]

Hey Joshua, could you by any chance get a schematic for the charging circuit?

[JoshuaZimmerman]

I don't build them, or make them. I salvage them from already made cheap Chinese chargers.

If you want to make one yourself, adafruit has kits you can buy as well as PCB boards. If you search instructables for "minty boost" there should be a schematic up for one there as well.

[JoshThebBoss]

Hello Joshua,
I thought this little invention is amazing and im choosing it to do it for my 8th grade science fair project. Only problem is that i don't have that charging circuit. am i able to use a female usb port instead? I also think using the usb port looks cleaner. if i can can u give me a small brief statement on how...i couldn't find anything tht tells me how and this is me last resort..please help!!ASAP

[JoshuaZimmerman]

Oh no! It won't work. You need the circuit to boost the voltage up to the 5V needed for iPod/ USB charging.

[JoshThebBoss]

Ok in yor past message you said-"The way to make this interesting to for you to do the test at the "recommended" angle and direction, and then try a couple of other. Graph it and chart it." so this means that i should face the solar charger in a specific angle toward the sun an see which angle harvest the most power? and how do i do this? will i not super glue the solar cell onto the altoids box? Ok improved question. What is the best way to mount my solar Ipod charger to harvest the most energy throught the day? hows it sound; does it make sense? and can you give me small details on the procedure on this project?

Thanks 4 ur help.

Josh Pisia

[JoshThebBoss]

Oh yes and i almost forgot,
I was just looking on your website and i saw the simple usb circuit for $0.75. Before i buy this i was just wondering; The AA x2 battery holder that i got from Radio Shack also has RED and BLUE wires just like the simple usb circuit. Do i solder the wires together by corresponding colors in order to have the charge go to my Ipod? Like solder blue wire to blue wire and red to red? thanks!

[JoshuaZimmerman]

I've sent you a PM about this.

Don't use a simple USB circuit. You need an actual boosting circuit to get the voltage up to 5V from your 2AA voltage of 2.4V.

[JoshThebBoss]

Wait so 2 AA battery holders = 2.4v + 2.4v = 4.8v?