Instructables

Repurposing a cell phone - the making of a rechargeable battery pack.

Long story short, I was in need of a 3-5v battery pack that was lightweight, lasted a decent amount of time, and wasn't too big.
So I looked around for something, I had plenty of rechargeable batteries that suited my needs, but none that had dedicated chargers for them.
And then I came across my old cell phone. Unfortunately when I was removing the battery contacts I pulled a pad off the board. And there were no traces nearby to solder the wire to.
So, being the person I am, I grabbed another cell phone and made what you see here.
I made this battery pack and charger with intention of using it in my fursuit, but you can use it for pretty much anything you choose to.

Was it at all necessary to do all this work? Probably not, but I wanted it to look good since I'd be using it a fair bit.
Read on to see what I did.
 
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Step 1: Tools and Materials

This stuff pretty much depends on how you want to do it, meaning you might not use the same tools (or materials) as me.

Some basic tools you will most likely need:
-00 or 000 Philips screwdriver (Or the appropriate screwdriver to disassemble your cell phone)
-Soldering iron and solder
-Scissors or wire cutters
-Marker or pen/pencil (I used a wet erase marker)

And any other tools that will make your build easier for you.

Some basic materials:
-Cell phone with its battery and charger
-Glue (I used hot melt glue and a glue gun)
-Wire
-3 pin connector (Female, two of these)
-3 pin connector (Male)
-Enclosure of some sort (I used the enclosure from an old battery pack)
-N/O SPST switch (Just a regular pushbutton, optional)

And you can use whatever else you want to make the finished product look nicer.

Got everything? Let's build!
RyanF1217 months ago
Do you have anything protecting the lipo battery? I just finished making my own from a 1000 mah ipod battery and two 800mah RC batteries. If the aluminum "balloon" surrounding the lithium were to break, your ear would catch fire. I don't think people at the conventions would be too apreciative of that kind of attention. By the way, do you remember me?
zack247 (author)  RyanF1217 months ago
I left the protection circuitry on the battery, and simply soldered the header onto that. I can't foresee myself using it long enough to fully drain it before I can recharge it though.

I feel as though I should remember you, but my memory isn't so hot sometimes ^^'
RyanF121 zack2477 months ago
I've become involved in the RC hobby and have lipo batteries that weigh 3 lbs and put out 11.1v with 5000mah for my multicopter. They have taught me how to rewire the connectors on the batteries, and a battery should ALWAYS have the female plug. You don't want to find out last minute that the protection circuit doesn't work when you bump the pins into something metal.

As for remembering me, do you remember AM?
zack247 (author)  RyanF1217 months ago
AM.. AcidMods?

as for the battery, my level of concern is rather low. I typically handle my batteries with some level of care and it usually has the contacts plugged into something, even if it is just a plug to cover them.

i suppose i probably should have put the female header on the battery, but i was a bit too lazy to do that, since i had no female headers at the time. so soldering the male header seemed like the ideal path.
RyanF121 zack2477 months ago
You are correct about it being acidmods. We talked a few times in the shoutbox. As for the batteries, I said the same thing about my lipos and had male deans connectors on all of them until I had my first fire. Since then, I have switched all of my connectors to prevent the same mistake. The risks of a lipo fire are higher for me though. I drive my erevo almost every day and fly my planes and helis several times a week.
zack247 (author)  RyanF1217 months ago
did you go by the same username there? it seems familiar. I havent been as active there as i once was since i got my car and whatnot, i still modify things but they're just small things and not really consoles of any sort.

I haven't got any hobby grade RC's since i can't afford them, but i do know some people who do and can. lipos can pack a punch, so i can see how fires could start.
RyanF121 zack2477 months ago
I went by RyanF on AM. I strayed away when I got into the RC hobby (funny story about that) but recently started coming back to it.

If you wanted to get into hobby grade RC's, you can get a used traxxas slash or mini erevo. They go pretty cheap, aren't very big like my erevo, and only need 1 battery. They also have some decent speed too. I've also heard good things about the losi micro T.
zack247 (author)  RyanF1217 months ago
i might eventually get into the RC stuff, but first i need to find employment somewhere so i can pay for the gas and plates on my car.
astral_mage7 months ago
usually the en key turns the phone off / on .
zack247 (author)  astral_mage7 months ago
indeed it does, and it does with this phone too. i just chose it because pushing the end key momentarily wouldnt execute any commands or anything like that. i usually just plug the charger in and go from there, but if you wanted to turn the phone on and then charge the battery, that works too.
ironsmiter2 years ago
Where did you find my last sprint flip phone?!?
And why didn't you convert the other 3 batteries while you were at it?

Guess I'll have to do it myself.
Since you've had the circuit board out already.... think it'd fit inside an altoids tin? I know it's narrow enough, but not sure about the length.

:-)

So, now I have a de-cased and re-cased cellphone cum battery charger.
And a second "project" phone.

Now, what to DO with it?

My first instinct say to make a flashlight out of it, and send the high-brightness light beaming out of the antenna hole. Maybe even the worlds bulkiest laser pointer?
What do YOU think?
zack247 (author)  ironsmiter2 years ago
ive found that the LED backlight assemblies are really cool and versatile things.
what i would do if you wanted a small compact flashlight, is take the backlight, rewire the LEDs in parallel and add a small resistor and switch, after removing the LCD. the backlights give off generous light and are really compact.
zack247 (author)  ironsmiter2 years ago
im not sure if it would fit in an altoids tin, to be honest ive never had one of them before.
i believe it should fit, but dont take my word for it. if you know how long an altoids tin is i can measure the circuit board from the phone for you.
Sure as Shootin, it fits like a dream.

Dark Chocolate altoids mint tin = 3.5"x2.125"x0.75" opening.
samsung SPH-A660 = 4.25"x1.825"x1" (With antenna removed, only 3.325" long)

basic decasing of the cell phone leaves plenty of room.
Dissassembly was super simple(as always .

#1: a fine screwdriver : remove 5 screwes. 1 by antenna, 4 under battery



#2 : Spudge open the case halves.( I was completely unsafe and used a

pocket knife. fingernails would work. it's just 2 TINY plastic clips)



#3 : disconnect screen cable(just pry it off. easy) #4 : flip phone over, and watch circuit board fall out.





Notes on MY version...

By removing JUST the antenna, the entire phone body will fit into the altoids tin(lid closes, and 99% latches. remove the screen for more space than you know what to do with). This means, I don't have to de-case the battery or solder AT ALL, if I don't want to :-)

I have a SECOND, fully functional phone identicle to the first(warranty return that the company didn't want returned) and 2 additional batteries. This can be shelled for a project, or left as-is to be used as a 3-batttery 911 car-phone.



Notes on YOUR version :-)

There is a 0.25" rare earth magnet in the screen bezel.

It was there to tell the phone if the screen was open or shut.

You can use this to your advantage ;-)

Most every flip phone uses this technique.

I THINK most slider phones do as well.

Might be a good way to control power to the screen and/or keyboard leds.
zack247 (author)  ironsmiter2 years ago
good to hear it worked out for you as well :3
i didnt worry about the magnet too much since the LEDs turn off after 30 seconds anyways, so i figured id leave it as is.

feel free to PM me pics so i can add them to the 'ible if you want :)
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