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[How To] USB Battery


prx984

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USB Battery, How To

I made a usb external battery, and I thought it was about time to show it. So, I have written a tutorial on how to make one.

First off, I'm just going to say that I dont warrent this project. If you screw it up and blow up a device, its your own fault. Not mine. I cannot be held responsible for what you do. Just gotta protect my butt here :lol:

First off, your going to need an IC, 9v battery connector, a small protoboard, and some kind of containor. Oh and some wire will be necessary.

Materials

1 X LM7805 (+5v voltage regulator)

1 X 1 inch by 1 inch protoboard

1 X Altoids, Colgate, or any other kind of small tin that can fit the entire project into

1 X Female usb adapter plug

1 X 9v connector

Construction

anywho.. once you have the materials, its time to setup the circuit. Ill explain how the LM7805 works. Theres 3 pins on the IC. The center one is ground, while the 2 outer pins are in and out positive. Input can be from 5 - 30 volts and the output will always be +5v dc

If you hold the LM7805 with the letters facing you, the first pin on the left is pin 1. That pin is input, the second pin is common and the 3rd pin is output.

Take the positive lead from the 9v battery connector and hook it up to pin 1, then the negative pin goes to the center pin. Its important to know that your going to have 2 wires coming off of the center pin as this is the common lead.

Your circuit should look a little like this:

diagramni6.png

Its a crude diagram, but it works.

Heres the pinout for the female USB connector. Make sure you hook up the + and - wires to the right pins on the connector, they should't be right next to each other. The pins in use are on either end.

Anyway, the next thing to do is solder it all together on a protoboard and manipulate it to go into an altoids or colgate gum tin. Also, you might want to cut a hole in the side so you can plug into it fairly easily.

Heres some pictures of my final product.

The inside of the tin:

sunp0004my5.th.jpg

The "tin" charging my iPod nano :lol:

sunp0006vu1.th.jpg

sorry for the crumby quality close up of the iPod, but the camera wouldn't capture the display for some reason <_<

If you decide to make one, post some pictures of yours here.

I searched on here for anything on how to do this and didnt come back with any results so I decided, why not post it here? I'm sure more people will see it here than on my forums. I'll take it down if need be.

-cygnus

Edit: Updated to include the pinout for the USB connector.

Edited by Cygnus
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nice tut, and simple schematic. How long does the battery usually last?

although aluminum isn't a very good conductor i'd suggest wrapping the entire inside of the altoids container with tape or something to prevent shorts.

and just a side note, taking 9 volts down to 5 volts (diffrence of 4 volts) doesn't require a heatsink pretty much anything higher then that will, so make sure you take that into consideration if anything besides a 9 volt battery is used.

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i ran my iPod off of it for about 3 or 4 hours, i havent really benchmarked that yet, i dont have a brandnew 9v to try this on lol.

the highest voltage i would recommend putting through this regulator would be about 10, although they say 30 is handled, i wouldnt go much higher. i used a piece of double sided tape on the bottom of the protoboard so nothing can short, it was from a cpu fan actually. the rest of the wiring i used heatshrink tubing to make sure nothing will short.

so far its worked quite well :)

thank you for the compliment ;)

Edited by Cygnus
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im not 100% sure, but i think that firewire uses a higher voltage, around 12 volts or so. so youd need to use more than 1 battery to acheive the higher voltage. i dont have a firewire port on anything of mine, so im not sure on which pins are to be used, but i could probably find it.

edit: heres the pinout for firewire, going by that, your going to need a much higher voltage/more batteries. the end result will be heavier than the usb version.

heres a person who has made an iPod firewire charger in the altoids tin as well.

Edited by Cygnus
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im not 100% sure, but i think that firewire uses a higher voltage, around 12 volts or so. so youd need to use more than 1 battery to acheive the higher voltage. i dont have a firewire port on anything of mine, so im not sure on which pins are to be used, but i could probably find it.

edit: heres the pinout for firewire, going by that, your going to need a much higher voltage/more batteries. the end result will be heavier than the usb version.

heres a person who has made an iPod firewire charger in the altoids tin as well.

What I find interesting is that the iPod, no matter what voltage you give it, will still charge. I have a Belkin iPod battery pack that uses four AA batteries, for a total of 6V. That guy's battery pack uses two 9V batteries in parallel and two additional AA batteries for a total of 12V (both 9V batteries deliver a voltage of 9V in parallel). He also has another one that uses a single 9V battery... :wacko:

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i saw a 4 aa battery pack at bestbuy the other day, but it was about 70 bucks :blink: i want one, but not that bad lol.

the next thing im going to be looking into is getting a replacement battery for my nano, the battery thats in it isnt much older than 6 months and its still giving my 12 hour run time, so i think itll be fine for a while yet. i always give it a good rundown every month just to keep it calibrated. i dont care what they say, the lithium batteries do suffer from the memory effect. heck, the batteries (battery X 2, both of my laptop batteries o_O) in my laptop did it. they would charge to 100%, but within 5 minutes they were down to 80%. i killed them dead (to the point that the comp shut off) and charged em, and they have been fine ever since. my iPod has already done it once, a simple recal fixed it :)

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Well, I don't want to criticize your project, which I like, :) but with the same schematics using 4 AA or maybe even AAA batteries should be better, as the IC will have to regulate only between ~6 V and 5 V instead of 9 V to 5V, and that should reduce the amount of heating of the thingy, it will also last longer.

It would also be interesting if you could use 4 NiMH rechargeable batteries, but since they are 1.2 V, maybe the resulting 4.8 V is not enough. :blink:

Specs for common Alkaline batteries:

http://en.wikipedia.org/wiki/List_of_battery_sizes

6LR61 (9V) 565 mAh

AAA 1200mAh

AA 2700 mAh

I guess one could easily make a 4 battery holder from an old remote, or you can buy one for a few cents:

http://www.allelectronics.com/cgi-bin/item...34;_LEADS_.html

http://www.allelectronics.com/cgi-bin/item..._AA_CELLS_.html

jaclaz

Edited by jaclaz
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iv got a 2 AA battery holder in my basement, but its way too big. maybe when i goto active components again ill look around and see if i can find a 4 AA battery holder and get a project box and put it all in one of those with an on/off switch and all that, maybe even a power led :lol:

4 aa's would work a lot better, but you would have to get akalines for sure, the rechargeables i have only reach about 1.33 when theyre just fully charged, and thats no load. i dont want this little box to be too heavy either, so thats why i used a 9v, 4 AA's wouldn't fit into an altoids tin i don't think.

ill post back if i decide to make a better one later one (which i think i will)

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