Step 2: The Charging Circuit

For this project I've stolen a charging circuit from an Emergency iPod charger I got off ebay. You can find these all over the place. The key is to find one that will work with an iPhone.

Apple decided to have it's newer iDevices not follow USB standards. When an iDevice is plugged in, it checks the data tabs on the USB to see what it's plugged into. Depending on what it finds, it sucks more or less power, which makes sense but is annoying because NOTHING ELSE DOES THIS. Thus no charger out there has any power flowing to the data tabs.

So the key is to find one that works for your newer iPod or iPhone. If you have an older iPod or iPhone when you don't really need to worry all that much.

(For a USB Version of this, check out this instructable.)

If you want to make your own circuit you can always use a Mintyboost kit.

Thorough and well thought out instructions...as would be expected from a teacher..<br><br>Appreciate the explanation of the non-standard apple implementation of usb charging....which probably explains why other gadgets such as my Garmin GPS and Palm Treo are aggravatingly finicky about their usb power supply..<br><br>Also appreciate your browndoggadgets.com site, as a source for small quantities of solar project related parts, that (I assume) have already been experimented with, as to their appropriateness for project/experiments (might suggest putting the wattage on the LEDs though).<br><br>One question I had: what would be a good source for the little tabs that one could solder on to NiMH AAA/AA batteries when replacing same in such items as Norelco rechargeable shavers and such? I have found sources for the Heat Wrap (like All-Battery.com) to bind multi-AAA/AA packs and such, but not the metal tabs (which would seem to be more stable/useful than a bit of wire, esp. when putting the battery pack back on the circuit board)..<br><br>Thanks again for the great instructable... bet you are one of the favorite teachers at your school..
Don't know if you still looking for this solution or not. <br> <br>But you can buy &quot;battery bars&quot; at just about any hobby shop. They come in various sizes, just bring in the cells you want to connect to get the size you need. I have some rather small lightweight copper bars. Bars used in multi cell RC buggy racing (If the jump to LiPo has not been made) are longer and at least an eighth inch thick.
This is an awesome website. I hope that you are able to make big bucks off of it. PS I really like the usb kit design. It looks rustic but also helpful.
Do you have any idea of how to identify a solar panels Volts and Amps?
<p>use a Volt/Ohm multimeter with Amps included usually cheap analog or slightly more for digital Most home building supply stores - even wal-mart.</p>
<p>Volt meter and amp meter.</p>
Do you have to have the blocking diode? <br>
<p>Very much so.</p>
Can i use a another Blocking Diode instead of the 1N914 Blocking Diode? Because they hardly to get in me country. Thank You.
<p>Anything similar would work.</p>
<p>this is awesome! But what if I use a different lightning to usb cable for my apple devices? I prefer the longer ones something like this one , </p><p><a href="http://bit.ly/legitapplecable" rel="nofollow">http://bit.ly/legitapplecable .</a></p><p>Do you think it will worked? You are awesome man. I think I'd rather do this one than buying a new one. Thanks I will keep you posted after I finished mine. <br></p>
<p>Use make up one with a standard USB port on it. It's much easier and then works with anything, including a lightning cable.</p>
So i purchased everything from Radio Shack execpt the usb port(ripped one from a car charger). Wired all together last night but didn't glue in tin yet. Wanted to test it today first. Noticed this a.m. that my positive wire from battery box came off so I just twisted them together and placed it in the sun. Went to check a few hours later and plugged device in but it wouldn't charge. The only way I can get it to charge it to untwist that wire then the solar panel will charge device if in sunlight but if i hook that wire up it stops....need help.
Wish you had been my science teacher back in the day!
I want one of these but I want it to have a usb and be able to charge my iPod or anything else I had lying around and I still want it to be solar powered I also want to get everything at RadioShack if u get back to me soon that would be greatly appreciated.
if I cant find something like this I guess I will go to a minty boost and see if I can get everything at RadioShack.
could i replace the charging circuit for a female usb port instead. what would happen
I'm mostly worried about the temperature that can be reached while charging under the sun. The eneloop datasheet ( http://bit.ly/YfvnqN ) says I can fast charge them up to 40 C. It doesn't say anything about trickle charging. What do you think?
i found a cable that looks like the one pictured, but was wondering if i still need to find something else? i don't think the bit with the capacitors on it is actually a part of the usb. sorry if this is a dumb question, im a DIY noob :3
Could I modify this with two pairs of AAs in a series-parallel arrangement? (one pair in parallel with the other pair, for double the capacity still at ~3V) Would I need a stronger solar cell, or would this one work fine?
What is the difference between this charger and your other solar USB charger? <br>-Doctordv
This has an iPhone cable, so you'd only be able to charge up iPhones or other apple gear. <br> <br>USB chargers have a USB port, they are generic and work with everything.
Quick question, how come you can charge multiple types of phones with your solar USB charger, but you are unable to use one phones wall charger with another phone? Thanks! <br>-Doctordv
You probably can. Usually it's due to the type of &quot;plug&quot; that goes into the phone from the charger. Each company has a different shaped plugin (unless they're nice and use a generic mini USB port), which requires you to buy stuff from only that company. <br> <br>Joshua
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.<br> <br> Most no name recharagables are <strong>50%</strong> at most.<br> <br> Second tier, what I call name brand generics like Tenergy, yield around <strong>75%</strong>+. (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.<br> <br> Name brands tend to be in the <strong>90-99%+</strong> range. Rayovac, Energizer, Duracell, etc.<br> <br> The <strong>kings </strong>are the <strong>Sanyo </strong>and <strong>Sony Cycle</strong> batteries. They test at 100% and the the results are exactly the same for each battery.<br> <br> -Bottom line is there is <em><strong>NO such thing</strong> as a</em> 3000mAh battery as far as I know.
-Bottom line is there is NO such thing as a 3000mAh battery as far as I know.<br> <br> Yeah, but there are 2850 mAh batteries like the ones in the pics.<br>
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. <br>If you tested the ones in the pictures, I really doubt you'd get near that number. Good luck with it though.
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.
Actually, they're in a series to increase voltage. Two of them together is 2.4-2.5V with 3,000mA. <br> <br>I switched battery suppliers awhile back because their batteries just plain sucked. I now use much better batteries. <br> <br>If you really want a long and steady charge, switch to Lithium. $15 will get you a charge controller circuit board and a decent lithium battery. Then add on a diode and a solar cell and you're golden.
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.
Okay, so I'm a newbie, but wondering if all i'd need to do is buy this device: <br> <br>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 <br> <br>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) <br> <br>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?
I really have no idea without taking on apart and seeing how it works. <br> <br>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. <br> <br>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. <br> <br>Plus having batteries is a really good idea. Solar is not consistent, and batteries or a big capacitor helps regulate the flow of power. <br> <br>Man, now I'm going to have to find one of these and take it apart!
Will the circuit boost enough to charge an iPad? I read my adapter and it says 10 watts.
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.
I thought you needed 5 volts to charge an &quot;i device&quot;. will it work the same with 2.4 volts or will it be slower?
The circuit boost the voltage up to 5. Thus why we can use 2 AAs.
Oh... right. thanks i get it now
SOMEONE PLEASE HELP ME WITH THIS: <br> <br>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.
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 ?
Because the solar cell charges the batteries, which then charges the iPod or iPhone
okay understood ! But how long will the it charge from 0% to 100% ?
<br>Hi Joshua <br>Thank you for this nice instructable! <br>its awesome <br>i was wondering if there is a limit to the voltage of the solar panel used? <br>could i for example use a 9volt 109mA solar panel? <br>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? <br>Thank you very much! <br>Sev <br>Amsterdam/Berlin
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.
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??
Charge the batteries up first, if you have a 3GS they're insanely picky.
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.
Mhn..and if I want to charge an iPad? what kind of cell should I use?
Because we're using small cells that have a limited output, we can't directly charge iPads. That's why we use AA batteries to store up a charge, which we then use to charge up bigger things. Like iPads.<br><br>If you want to directly charge up your iPad you're going to need a big panel that throws out more than 500ma of current.
where can i get the charging circuit??
You'll need at least 1amp of output for an ipad

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Bio: I used to teach middle school science, but now I run my own online educational science website. I spend my days designing new projects for ... More »
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