Picture of 6 million rupee LED flashlight out of a Lithium Battery!
This pocketsized flashlight packs more amphours per ounce into your pocket than anything you could buy... if you dare to make one.

Step 1: "Make an LED flashlight out of ..."

Picture of "Make an LED flashlight out of ..."
You've seen them. They propagate like syphilis. They are Unoriginal LED Flashlight Instructables.

"Make an LED flashlight out of ...":
an Altoids container!
a Tic Tac container!
a Mini Altoids container!
an empty 9 volt battery container!
an Altoids gum container!
an empty film canister!
a used wad of toilet paper!

Well, this one is DIFFERENT. It's difficult, dangerous, and just plain time-consuming. So don't try this at home, unless your middle name is Danger. And you first name is Nerd. So, you're still interested? Ok, then. Step into the light.
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joeofloath5 years ago
You don't know a short circuit until you short a 7.2v, 4.5ah ni-mh RC car back, The wires glow red hot, and the cells go off one by one like shotgun cells.
nimh can give about 8 amps in short circuit max but car battery can give 20-100 amps so if you short car battery it will be about 1200 W in short circuit and with nimhs you will get about 58 W :D
It's not that simple I'm afraid, it depends on the C rating of the cells and how big they are. A 300mAh nimh from a wind up torch will give maybe 150mAh, but a massive cell the size of your head (like they used in the GM EV1) could pump out hundreds of amps.
i have AA 1.2v 2,1A nimhs and in short circuit they can give 8 amps like most of new nimhs so they can give 4C for 2-3s
Or a car battery. But I've never done that. Well, apart from that one time with the 5 inch electric motor...

Lwts just say sparks flew, and rather thick metal glowed.
how do you re-charge it?
You programmed a PIC ? I don't want to sound like a wet blanket, but .... isn't it (a lot) cheaper to buy a flashlight than a microcontroller ?
klee27x (author)  ElectroFrank4 years ago
The whole point was to make something that I cannot buy, and to reuse some "dead" laptop cells. I still use this flashlight, today, with no mods or repairs.

BTW, microcontrollers probably cost less that you think. This one cost me about 60 cents.
Fair enough, I'm obviously not keeping up with prices going down ! And I guess the practice of programming is always good. BTW, can you recommend any sites where I can pic up PIC programming ?
(I have a good basic training in microprocessors, it would be nice to find a teaching community and coding tips. As the PIC and PICAXE system is well supported as an educational tool, it seems like a good one to get one's teeth into.)
klee27x (author)  ElectroFrank4 years ago
There are a lot of online tutorials that will get your feet wet. But the most imortant stuff is in the datasheet. I suggest you print out the entire datasheet (all 200-450 pages) and bind it into a book. There is a lot of info in there you'll need to refer to frequently, unless you have a photographic memory.

Microchip has fairly active forums if you have specific questions. But to formulate a specific question, you'll have to read the datasheet. :)

As far as learning assembly coding tricks, Micochip has dev boards and tutorials for various devices. If you can follow the schematics and/or make your own boards, you can then download the turorials for free. They'll cover some basic programming tricks, such as making delays, using interrupts, how to make macros and subroutines, etc.
how do you program the thing?
klee27x (author)  elinventor214 years ago
That's a bit more complex. I suggest you look up some microcontroller tutorials if you are interested in that.
konger5 years ago
What 'bout the PIC program and the circuit diagram?
maxpower496 years ago
what if my first name is danger and my middlie name is nerd
klee27x (author)  maxpower496 years ago
Then I'd like to meet your parents.
Their names are Toil an Trouble.
and the father's name is bubble. so now they're bubble and bubble. first names toil and trouble.

her maiden name was schmidt. quite unoriginal.
me gusta......
Mejor con in poco de funda termoretractil
nerd125 years ago
are you indian?
what does the title mean?

D5quar35 years ago
 what's the point of a PIC do I really need it
klee27x (author)  D5quar35 years ago
As I explained, it's only there so I could use a super kewl tiny push button to toggle the flashlight on/off. You could just use a switch, but that would only be kewl. Not super kewl.
 just plain awesome but too dangerous for me
 could i use a button battery? (3v x 3) 
klee27x (author)  northernmagnet5 years ago
Dunno why you would want to spend that much time on a small disposable battery, but yeah. It would be litte more than a throwie, though. :)
Redgerr6 years ago
""Make an LED flashlight out of ...": an Altoids container! a Tic Tac container! a Mini Altoids container! an empty 9 volt battery container! an Altoids gum container! an empty film canister! a used wad of toilet paper!" AHAHAHAHAHAHAHAHA YESSS -- other than that.. amazing cheif, i really like this and i have a TON of 'dead' laptop batteries around my house (just disasembled 2 laptops and 3 desktops LOL) and id love to try this!! Thanks!
luketanti6 years ago
Hello. I have a bunch of these batteries and i need to know : Can I charge 3 cells in series which makes 11.1volts with a 12.6 volt LM317 charger without any protection circuit? I'm going to use them to power a portable amplifier. The battery model is CGR18650hm Panasonic.
klee27x (author)  luketanti6 years ago
Well, it could be done, but you'd have to find out yourself what the max current is. A TO-220 lm317 can sustain >2A output if it's properly heatsinked with a fan. So you'd be relying on a nonheatsinked part, possibly of a smaller package (like a Dpak) to limit current to under an amp or so, and it would get very hot. I'm not sure how long a 317 would last if used like this. It's kinda a hack method, and I don't really recommend it to anyone.

It's far better to use a variable output supply and an ammeter, or to use some active current limiting.. or even passive current limiting. A 5 ohm 5 watt resistor in series with the battery would pretty much ensure a safe current limit for a 3 cell battery charged at a fixed 12.6V. But it would also increase the total charge time by quite a bit.

Dirk57 years ago
have u herd of mega capacitors they stor like 300 farads once i get my hands on i'll make one with one of those
klee27x (author)  Dirk57 years ago
I thought they were called "super" capacitors. Yeah, those are pretty neat. Add a high efficienty DC-DC converter, too, while you're at it!
Dirk5 klee27x7 years ago
actually i hate to correct you but there is something called mega capacitors but there super new and hard to find
also ultra capacitors
Also super duper ultra mega capacitors.
also super'duperpooper'scopper capacitors
what is a scopper?
it just goes in with everything else
i really hope all you guys know that capacitors only hold their charge for less than a second, in other words, once you discharge it, all the energy leaves at one time, not like a battery.
not so...it depends on how you discharge it.
seriously. if you have a 5- or more farad supercap it will run a low power led for at least 10 minutes. however, if you short it with some wire it will run out in less than a second.
i made an led keychain light with a pair of .5F 5.5v super caps and it runs for 15 minutes. but it does self discharge after a few days though.
add a solar panel to charge it with sunlight. maybe make it a pull-out compartment so the panel doesn't break. see if you can find one of those flexible solar panels that will roll up ti fit inside it. new tech. awesome.
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