thanks to everyone’s great feedback, i’ve now got a usb battery that’s much more efficient and capable of delivering more current to a portable device. like i promised, i put together a slick little case to finish this hack off right. read on for some tips on building your own.
quick improvement
as mentioned by several readers, you’ll want to use a 5 volt regulator ic instead of the resistor/zener-diode combo i discussed previously. you’ll be able to charge your device faster while it is running and it’s much more efficient, which will give your 9 volt a longer battery life.
the best part is that it’s easier and cheaper to do it this way. just grab an lm7805 from your local hacker store and wire it up. connect the positive battery terminal to the 7805 input pin, the positive usb pin to the 7805 output pin, and connect the negative battery terminal and the usb ground pin to the 7805 ground pin.
which is which? if you hold the 7805 with the text facing you and the pins downward, the pins from left to right are: input, ground, output. it looks like this:
for the female usb connector, look down into the end of the connector so that it is oriented like so:
pin 1 is the positive (5v) terminal (which goes to the output of the 7805) and pin 4 is ground (which goes to the 7805 ground pin).
easiest way to test
several people were wondering how to tell if you are going to fry your device. here’s the easiest way to test when you are all done wiring:
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cut a standard usb cable in half.
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plug the male end into your usb battery.
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connect the positive and negative ends of your multimeter to the red and black usb wires respectively.
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if it reads something very close to 5v then you are wired correctly.
making a case
i chose to make my case out of polystyrene plastic. you can find this stuff in sheet form at most hobby stores. it’s the same kind of plastic used in your standard plastic model kit and the sheet form lends itself nicely to making flat sided objects
well, the above mod work great, i am now doing a test to see how long the batteries last.
Ok, it turns out i was mistaken in a few of my above posts.
I stated that only the ipod shuffle has the ability to charge from USB. According to the wikipedia article on ipods
http://en.wikipedia.org/wiki/IPod
the 4th gen big ipod and the 2nd gen mini also have support for usb charging
that said, DO NOT FEED ANYTHING MORE THAN 5V INTO YOUR IPOD. If you supply 12v (or anything about around 5v) you’ll almost certainly fry the thing.
Supplying 12V through the FIREWIRE port SHOULD be ok.
#140:
As for the external hard drives, its probably what #141 said. But personally i woudln’t connect anything to any of my precious USB devices (especially if I had a bus-powered external HDD) unless it had been through a voltage regulator first.
Well 152 is right, but USB devices should handle a max of 5.25v without problems.
I was wondering if someone could make a diagram for 4 ni-hm batteries in a altoids box, with a switch to kill the drain from the batteries when not in use and a led for activity. also I’m looking for a way to plug an external power source to recharge the ni-hm batteries.
also something off topic:
my electric shaver does not keep a charge that long anymore. it has 2 AA ni-cad batteries inside that have a piece of metal attached to the ends of the batteries then it’s wired inside in the shaver. If i would to take the metal ends off the ni-cad batteries and install 2 AA ni-hm and resolder the metal back to the ends of the batteries, would that work instead of replacing with ni-cad? which is better ni-cad or ni-hm?
as a reply to 154, DO NOT SOLDER NI-MH BATTERIES. WHile it is possible and it will work, you activily destroy the battery’s seals, causing gasses to leak out and corrode electronic components nearby. This is a common problem with RC Car builders.
As for the schematic, I am working on that kind of design for myself, but I do not have the time right now. I’ll post in the future when I get a design going.
thanks for the info. If I were to super glue the metal contacts to the ends of the batteries either ni-cad or ni-hm would it still get the connection? thanks
Nick, aslong as the superglue doesn’t get between the tabs and the battery, it should.
If you live in the uk you can purchase a Small narrow box for 1
thanks, now works better!!
I must say that this works great if you have a USB charger cable for it! But, I’d ratcher use the diode desing so I can make it give 4.5v instead of a stright 5.0v (because I don’t want to blow my $250 mew gadget!)
Errrr…messed up on 160…I ment to say it works great for the PSP
Hey! I’m having trouble using this thing with my iPod. It is a regular 20 gig, 4G iPod. It CAN be charged through USB cuz it does when you connect it to the computer. I’m almost 100% sure that I wired it right, but it seems to drain my iPod’s battery instead of charging it. Is there a way to fix it so it charges it? The charging meter comes up as usual and it appears to be charging. I left this thing on for like 5 hours, came back, and my iPod battery was almost dead. HELP!
In Australia jaycar (www.jaycar.com.au) stock the USB terminals that are needed, but they arent cheap at AUD$2.20 for 1.
Question:
Using a DC wall plug pack that puts out 500ma at 9v how would I go about dropping it down to 5V?
Thanks Doc
RE: Frank Cummins
I have the same problem with a 4G 40GB with a AC to USB wall adapter. The ipod display shows charging, but the battery drains and the iPod gets very hot. I think there may be a requirement for a signal through one of the other usb pins to enable USB charging.
Ro
i just built one last night, except that i used a radio shack project box. love it!
re #162 and #164
a couple of people above noted that you have to solder the pin 2 and 3 wires to ground for an ipod shuffle. The same thing might apply to a 4g ipod.
re #163
try a 7805 voltage regulator, like this one:
http://dseau.resultspage.com/search.php?p=R&srid=S8&lbc=dseau&w=7805&url=http%3a%2f%2fwww%2edse%2ecom%2eau%2fcgi%2dbin%2fdse%2estorefront%2f%5fsessionid%5f%2fProduct%2fView%2fZ6545&rk=1&uid=239927058&sid=2&ts=p2&sessionid=4279c7e509849594273fc0a87f9c0790&method=and
or
http://www1.jaycar.com.au/productView.asp?ID=ZV1505&CATID=&keywords=7805&SPECIAL=&form=KEYWORD&ProdCodeOnly=&Keyword1=&Keyword2=&pageNumber=&priceMin=&priceMax=&SUBCATID=
BTW I would measue it with a multimeter and make sure you do in fact get 5v from it before I plugged anything in to it, if i were you. Also it would be a good idea to check to see that the current isn’t much less than 500ma
nice. couldl u use that to charge a PSP or DS becuz im pretty sure those need 5v to charge….
I attemted to make one of these for my ipod photo (30gig) and had the same problem as #162. I have also taken pins 2&3 to ground, like i have heard needs to be done for the shuffle. Without taking those pins to ground i didnt seem to get any response at all. Also, when i first tested the voltage i got around 5.02v (i dont remeber exactly, but it was just above 5v) after attemting to charge for a few hours i tested again and got 4.88v. I am using 4 AA batteries insted of a single 9v. Is it possible that it drained the batteries and didnt charge?
re #167
yes you should be able to, if you can find the right connector for the DS/PSP power in port
re #168
as i found out, 4xAA batteries are not very appropriate for this type of project. The 5v regulator causes a voltage drop of ~2v, so you need at least a 7v supply.
i wanna purchase some of your items
whatever you do, do __not__ try to skip the voltage regulator part! i fugured that since it’s written 5-30vdc on the back of my ipod, it would handle 9v directly all fine, but i was proven wrong… my ipod is now dead, and all i got out of it was that i spotted a new battery icon with a warning sign on it. guess that was a bad sign…
of course, the ipod has a internal voltage regulator, but i guess that the usb power pins bypasses it since it always expects to get 5v computerish power (guess that the ie. the hdd runs on 5v, beeing a computer part)…
jeeze all this over making an external battery pack… heres an even better solution make it WIRELESSLY CHARGED. i know it might sound like a hoax but i did it to my mouse.take a 5v 12A powersupply feed it into a NE555 ic after it goes through a resister. make the right circut for an astable oscillator and use the square wave that comes out as a trigger for a bigass FET send the power through a coil of magnet wire before it goes back to ground. plug that into a portable generator that you have in the wagon behind you and on the ipod have another coil around a ferrite with a diode to mooth out the current AC-DC it should be able to charge the battery from your shirt pocket. just snake the cord through your shirt and try not to look like an idiot while wearing this thing.
hey, i would either ike to make this, or a firewire charger for my 4th generation ipod.i have an extra dokck to firewire cable that i chopped the firewire end off. i just need to know, which wire (clear or black) is power or ground? thats all i need to know. thanks!
waaay back in post #8, brk suggested using a national semi switching regulator or similar to help get rid of the excess heat produces by the 7805. Has anyone tried this?
Also, is there a wiring diagram available, Jason? Or a website with ALL of the great ideas people have tried here, with parts lists and diagrams?
hy i just want to make an usb-to-wall adapter,for that, i have a phone charger that gives me 8.7V. i was thinking of buying an lm7805 to get it down to 5V and a female type A usb connector and “atach” these things to the phone charger..what do you think? will it work?
i’m planning to get an ipod later this week and i wanted to build a charger. does the ipod come with a cable that allows you to charge with usb or firewire, or do you have to buy that separately?
also, is it correct that i should use a 5v regulator if i wanted to charge with usb and a 12v regulator for firewire? is it less likely to fry with usb?
I was wondering, I have the hole cut in my mint tin and I have the female usb end cut and the wires exposed. What wires are what, since they are encased in some thick plastic? like which wires are needed for me to solder to the voltage regulator? the black is ground right and the red is the 5 volt?
i just checked, and the charger that goes with the nintendo DS or the gba: SP has a voltage of exactly 5.2, so technically you could just chop the nintendo end off and solder a female USB plug onto it.
When I was tearing apart a usb cable for the female end, I accidentally tore out the pins, so I just ended up using the cable that plus into the usb on my zen micro. I also added a switch so I don’t have to keep unplugging my battery. The other cool thing is it all fits inside a box that a deck of cards came in so its completely disguised. Then when I want to recharge, I jsut open the box, plug in the cable, and flip the switch and it charges. I did run into a bump though, probably because I have a zen micro, it wouldn’t charge unless I had the white and green wires from the cable soldered onto the ground of the recharger, I wonder why it needs this.
-Peace
i have an iaudio u2 and I wired up everything correctly, including the white and green wires to ground. but when I plug in my u2 it doesn’t appear to do anything. if i press the on button while it is plugged in it shows that it’s connected for a few seconds and then turns off. any ideas?
i have an iaudio u2 and I wired up everything correctly, including the white and green wires to ground. but when I plug in my u2 it doesn’t appear to do anything. if i press the on button while it is plugged in it shows that it’s connected for a few seconds and then turns off. any ideas?
I bulit one using some AAA and the voltage regulator for use with my iPod. I cam across a problem when I tested it out. the iPod detects power and but doesn’t use it to charge or to power itself. I then ran the iPod on my computer using the data on the cable bu the power on the battery pack and it charged fine. I am looking into how the AC adapter for the iPod is wired so it will charge without having to be used by the computer and have normal use on it. any suggestions?
ok, after working on it some more I found a solution and have been able to charge my iPod. I connect the iPod to the batter and then reboot it pressing play and menu for a couple seconds at the smae time (I have a 30gig iPod Photo) and then it will run on the batter and chanrge itself. now all I need is a case. here’s a picture of it charging my iPod: http://home.comcast.net/~ditto_125/pictures/ipod_battery.jpg
i made one for my ipod as well built from an extra dock that i had lying around works great thanks for the inspiration
btw, i decided that i was going to make this (to charge a shuffle). here are the pics that i took of it. the main difference between this and the how to here is the addition of a power switch between the 9v battery and the regulator. also, you’ll notice 2 usb ports. that’s because i got it for free and that’s all they had. currently, both are soldered together. lastly, i dont know if this makes any difference at all, but the regulator is a CW7805, not LM. can anyone tell me the difference?
http://home.comcast.net/~michaelprice/Pics/Pic1.JPG
http://home.comcast.net/~michaelprice/Pics/Pic2.JPG
http://home.comcast.net/~michaelprice/Pics/Pic3.JPG
Just a quesion; how did you cut the altoids tin? It’s really hard to do it neatly.
i used a pair of tin snips to cut the place for the usb port. the whole for the switch was just punched out with a nail. you should be able to get them at walmart or home depot. these ones are pretty similar (found on google images) http://fcsurplus.ca/tools/images/402981b.gif
Ah, I see. Gotta get some of those.
i tried to build one of these to power my 4g ipod. i followed the directions exactly (i think) and it didnt work. all it does it drain my battery. i tried to reverse the polarity, but that just made the regulator super heated. should i not be doing this for my 4g? or am i just really really stupid at making these things? what am i doing wrong?
Okay.. I made one of these.. it gives out 5.2 volts with a perfectly new battery. To use with my ipod ((4g 20gig or 60gig photo)) what would I have to do? I was thinking combining 2 9vs and a regulator to make it some voltage that the ipod needs. Maybe 12v, I’m not sure. Can anyone help?
yay! i got mine to work (i’m the complainer from post 190) by, as i read after i had posted, grounding the usb cable. for post 191, it seems to be running fine on the 5 volts that it’s putting out. my ipod is charging now, we’ll see how it goes later. i put it in an icebreakers tin, seeing as how everyone else used altoids. support us products!
For anyone trying to get this to work with their 4G iPods, I’ve just made a variation on this thing, except I used a KA7805 (absolutely no difference between the KA and the LM7805 from what I’ve read), using 7 AA batteries (I had a 4-AA and a 3-AA container lying around). What normally happens when I turn it on/plug it into the iPod, is that if the iPod is off, it will turn on, but will not charge. If you put it to sleep, the animation won’t come on, and it will still be sleeping. What I did is I shorted the data pins on my connector (the remaining two pins in between the + and – pins). When you plug it in, it still won’t show the charging animation at the top-right part of the screen. However, if you have “Sleep” enabled in your menu (check Google on how to make it show if you don’t have it there already) or if you hold Play for 3-4 seconds to make it sleep… the charging animation will show – it’ll be charging. If you press any key again to start the iPod back up, you’ll now see the charging animation – the iPod now knows it can now charge. What I think happens is that when you plug the iPod into the USB jack on your charger, it detects the voltage, and tries querying the data ports, asking “Hey, what am I connected to? Who are you? Can you give me power?”. Of course, it gets no response, so it does nothing, even if the pins are shorted. However, when you put it to sleep, it once again does the query, but apparently slightly differently, as this time shorting the pins will work, and it’ll accept the charger as a power source. I’m not sure if this will work for you, but it did for me. I’ll be posting a quick guide (complete with link-back to this article and pics explaining the process) shortly on my site, http://varu.ca. Good luck :)
Or not.. hooked the two shorted pins to the ground as well just to try it out.. both variations drain the iPod’s battery. If I had the time and skills to do this, I’d put an osciloscope and a port monitor on and see exactly what the iPod and the comp tell eachother when you plug it in… but I think the better alternative is to just go with the FireWire, it seems to work with that one. Probably cause of the different pinouts on the iPod connector.
I have my and this usb battery works only as a “aditional battery” The AA, AAA, 9V, bateries doesnt have power enought to actually charger the ipod mini.
Right now im playing with my car’s lighter and built a usb lighter adapter. With this one i am able to actually charge my ipod battery.
cheers
PC
Hey how do I charge my hp h4155 pocket pc its 2000mA
Hey how do I charge my hp h4155 pocket pc its 2000mA
Hey how do I charge my hp h4155 pocket pc its 2000mA
196, 197, 198:
what voltage does the ppc wall charger output?
check out the datasheet for an LM338T current regulator
I’ve made the battery, but im a little scared to try it on my iPod mini. Does it really kill the iPod, and if it breaks can i fix it?
PS i have to warranty