Silly question – Most of these projects are focused on ‘charging’ ….(i.e. plugging into a portable device that already has a rechargable battery inside it – what about simply fashioning a custom rechargeable (lithium ion?) battery pack for a device ….(to make it truly portable)? like for this recent item (Aivx) -
http://www.cooldrives.com/aidimi2usbdr.html

i bought the 7805 now where can i get usb/firewire conector

response to post 105:
4xAA gives about 6V. The 7805 requires 2 volts of “drop-out” to create 5V. In other words, you need at least a 7V input for the 7805 to reliable output 5V. If the input is less than 7V, it may or may not work. also when you attach a “load” to the battery, the battery output voltage will appear to drop slight due to the internal battery resistance.

response to post 99 & 103:
i was thinking of using the MAX1675 step-up DC-DC (http://www.maxim-ic.com/quick_view2.cfm/qv_pk/1878). It will operate on as little as 0.7V input and is very efficient (up to 94%). that means it will work with a single AAA (as in very light charger). it is also very cheap (~$2). the only problem is that it is surface mount, so it’s hard to work with. the 78SR105 solution looks interesting though. it is no longer recommend by ti though. they suggest the PT78ST105 .

btw, i am an electrical engineer working on a battery powered device at work, so i know a little about this stuff.

In response to post 106.
That seems like a great idea. The 9V nimh I’m using now have very poor power density. A couple of AAA or AA should be around the same size and pack much more power. Any idea on how to wire up the MAX1675? Not only is it surface mount, it’s really tiny as well.

As for the PT78ST105, it’s not suitable as it requires a minimum 9V input. May not work properly with a 9V battery.

I used a USB to PS/2 Converter as the Converter has a female USB.

When I try to charge my ipaq, it makes the backlight come on and shows charging, but the battery continues to drain, no matter what I turn off. Doesn’t seem to be charging. Am I missing something? Connected to 1 and 4 on the usb and getting 5v out.

I made a USB battery for my Ipod shuffle but when I checked the volts I got around 10 or so, any idea what I did wrong? It looks like I put the wires in the right place, I used the website in post 109.

RE #113 and #111

The ipod (3g i’m sure about, probably also applies to 4g) are not designed to charge AT ALL through the USB port. I don’t think it is very likely, but it is possible that the ipod completely ignores all power coming through the USB.

Based on my (very limited) knowledge of the way these things are designed, I think that it is VERY LIKELY that the USB controller inside the ipod pulls power from the USB port. In which case, connecting it to a USB that outputs 12v wuold almost certainly kill the USB controller and probably the entire ipod

Does your ipod come with a wall plug? If so, you could sevre that half way, solder a barrel plug onto the power adapter end, and a barrel socket onto the ipod end. And make a battery pack that produces 12v and has a barrel plug for power output. Just make sure you use the same polarity on all three (positive center is usually used)

SO: If you fry your ipod by connecting it to 12v through the usb, it’s your own fault. I think that its a very stupid thing to do.

#115
My recomendation: if you can’t find a store that sells firewrite connecters, find and buy a firewire card for your pc that includes an internal firewire port, like this one:
http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&category=3666&item=5178936708&rd=1

As if you’re ever going to open up your PC just to plug in a firewire device. So use some desoldering braid to de-solder the internal firewire port. If you do it properly (don’t short anything on the card AND don’t desolder anything else) you should atill be able to use the card.

(Here in Australia, I couldn’t find a store that sold USB sockets. So I had to vandalize a USB extension cord to make my USB battery.)

On another note, I now have an ipod shuffle, but its the 1GB version and i don’t want to take the risk of plugging it into my USB battery. Aside from the AU$230 I have to scrounge up to replace it, it is very hard to find a store that has them in stock. For anyone else in Brisbane, Australia, Infinite Systems ( http://infinitesystems.com.au ) had stock last Wednesday, but I doubt they still do.

So, at least for now, my usb battery will not be tested with my shuffle. I might buy that external battery pack that apple sells.

hey would this work on my new dell axim x50

#117
Buy a 5v power supply and wire it to a USB cable. You probably should not try to make your own power supply unless you know what you’re doing, as it can be dangerous. The power supply unit should be rated for at least 500mA.

#119
Did you connect the LED in series?

#119: what type of power supply are you using for this? I originally used 4 x AA, but found they didn’t supply enough voltage. A 9 volt battery is far more effective.

re #123
yes it is possible. solar cells produce about 4w, so you should be able to do it with one or two cells. However, I would recommend using at least 4.

You would have to wire them up the right way to get the right voltage and amperage. And personally, I would hook the cells up to a voltage regulator.

It won’t work (at all) unless the panels are directly facing the sun AND there is no cloud cover. So if you build one, you won’t be able to use it in the middle of a city. Or even on the outskirts. I’m guessing you want this for a long drive? You wouldn’t be able to generate enoguh power unless it was on the roof of the car AND aligned properly.

If you want this for a long car journey, buy a cigarette lighter plug, and connect that to your voltage regulator. Power the whole thing off the car’s battery. Because most cars have a generator to recharge the battery, you’ll be able to use it as long as there is petrol in the tank.

Belkin makes a cigarette lighter plug adapter for cars that has a USB port, and a red LED. It puts out 5.5V and one sticker said 700 mAh at input of 12 to 24V. I use it to charge my PDA. I tested it with 9V from 6 AAs on the input and it appears to put out 5.5V and charge my Sony PDA’s 3.7V Li Ion battery through its USB cable. You can pull out the ciruit board and put it in a box, or make a box with a cig lighter port for this to plug into. They have a PCB with a switching chip and several diodes, resisters and caps. I have found these for $1 at the 99 Cents store (packaged with cellphone and PDA USB cables) and for $1 at an electronics swap meet.

#126
What I meant was that you should check to ensure your led is not connected in series. If you connect the led in series, there will be a voltage drop, and your phone will not get the full 5v. The led should be connected in parrallel with a resistor to limit it’s current, and the led and resistor together should be in parrallel to the 5v supply to your phone.

Depending on how much current your phone draws, it may be normal for your battery to run a little warm. But I think it’s more likely that something is shorted here. Check your wiring again.

129:

Well, you’d have to figure out on what voltage the PSP charges and get the appropriate adapter. If it was, say, 12 VDC, you could get 2 6v batteries hooked up to a diode (so the current doesn’t reverse!) then hooked up to an adapter that fits into the PSP’s charging socket. If it’s less/more than 12 VDC, add/remove batteries and add a voltage limiter if needed. I’d imagine that it’d charge rather slow, since the current isn’t too strong, but it should work.

Anyone know what voltage PSP’s charge on? I should make one of these for a friend with a PSP (heh, lucky fucking bastard)

cool…wanna try it myelf…

Has anyone else noticed that hackaday converts all your comments to lowercase???

I just purchased a pcmcia usb card in order to add usb ports to an old pre-usb notebook, and wouldn’t you know it, *the card needs a usb port to power it* (catch-22)! Geez.

So I went searching online for a way to power it with an external battery pack, and found your article. Can’t wait to try it. (I’ll have to canabalize an old USB/PS2 keyboard adaptor for the female usb recepticle because they are impossible to find.)

Keep up the good work.

using USB/PS2 adapter… you don’t have to take it apart…just find the 5+ and ground on the PS2 and connect it to those 2 pins

#139

no i don’t have a multimeter

i’m trying to use the 9V setup since i tested the harddrive with a several configs.

i tried
3AA alkaline = 4.5V. (HD doesn’t start)
4AA alkaline = 6V w/ VR (doesn’t start)
4AA alkaline =6v [no] VR (doesn’t start)
6AA alkaline = 9V w/ VR (HD starts up)
4AA NiH = 4.8 (starts up)

so since the 6AA=9volt worked. I’m using a 9Volt battery since it takes up less space than 6 AA. since my current set up is like the one described here using a 9volt battery.
can someone measure the amp output?

great portable battery. i hooked my own up and found that it works great for an ipod mini or iriver H3** great!

I own a 40 gig Ipod and I charge it every day thruoght the USB port. It is a fourth generation so maybee usb support is new. I built one of these and it doesnt seem to work right. I wired it correctly am getting 5.2 volts out but my Ipod doesnt take a charge from it. The backlight comes on when I unplug it. I havent tried shorting the data pins yet, will let you know if this works.

I’m crap at electronics! Can I buy one from someone?

Thanks again.

P.S. Great idea!

Matt/#146 I’ll make one, but how much are you willing to spend >:)

This is just for those who want to use this for a psp battery.

4 nimh rechargable batteries in series provide a peak voltage around 5.4 volts. during their power discharge curve, they tend to level out around 4.8 volts, and when they start to run out of juice (roughly less than 10%) their voltage starts to fall rapidly around 4.65 volts. Of course, these values will be different depending on the brand of battery.

The psp power supply I have outputs 5.4 volts, so the rechargable batteries should not overvoltage the psp, and using an adjustable power supply, the psp will continue to work (without the internal battery) until the voltage drops to about 4.65 volts.

So, now I am going to simply plug 4 batteries (nimh) to the psp power input. I figure it should work, and from my estimates, it should last as long a the standard internal battery. to keep currents low I plan to use this as a supliment to a fully charged psp internal battery.

On a side note: Usb specs state that a usb port will need to provide 5 volts within a range of 4.75 to 5.25. any usb device worth working with should be able to hande this range also, to it should give you some margin of freedom to play with. I hope this tidbit helps.

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.

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?

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

If you live in the uk you can purchase a Small narrow box for 1

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!)

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!

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

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

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 #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.

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)…

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!

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 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?

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?

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

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

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

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?

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!

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.

Hey how do I charge my hp h4155 pocket pc its 2000mA

Hey how do I charge my hp h4155 pocket pc its 2000mA

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