Instructables
Modifying a small laser pointer to accept larger batteries.
 
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Step 1: Modification

I had a key chain laser pointer that soon became my dogs favorite toy. (He loves to chase the red point around) Unfortunately the batteries would run out after a few hours of play. At $4.95 each the batteries are pretty pricey and the pointer needs 3. I decided to modify it, to use regular batteries instead of the expensive ones.
What you will need:
- laser pointer
- car cigarette lighter plug
- hose clamp
- 4 AA battery holder
- electrical tape

Step 2: Assembly

- solder a positive and negative wire to where the batteries fit in the laser pointer
- fit the wires through butt end of the cigarette lighter connector
- fit laser pointer into butt end of cigarette lighter connector (might have to use electrical tape to butt fit it properly (red tape in previous picture))
- the old batteries were 1.5v each, that means we need 3 AA batteries to have the same voltage
- attach clamp in the middle of laser and cigarette lighter connector
- attach battery holder to clamp
- attach wiring to battery holder
- insert batteries and test

Final Notes:
After extensive testing, a set of batteries will last a year or more. It looks like a funky alien weapon but it makes great fun for my dog and koi fish.
pcanywii6 months ago
I'm not good at making instructables so I want someone to make an instructable about uses of a laser pointer. I guess they can entertain you but not a ton... ??
cochrate5 years ago
solder a positive and negative wire to where the batteries fit in the laser pointer - I would like to do this for a different project it is not working for me. where exactly do you solder the wires ? Thanks
If You dont want to disassembly this cheap laserpointer, You may solder negative wire to string and positive wire to tapping or casing. If You have extracted board, then negative wire to point, where was attached string and positive wire to contact, where was attached casing of pointer.
ronaln3045 years ago
or the another way of power is to plug it in your usb port on you computer. it is 4.5 volts
Good idea, but I'm pretty sure usb is 5 volts, I could be wrong though
Yes, it is 5V. But, when I play with my dog, my PC/laptop rest home.. So, nice idea, but for other use..
f4ngu57 years ago
you said, "the old batteries were 1.5v each, that means we need 3 AA batteries to have the same voltage". However AA batteries are 1.5V anyway. Also are your batteries in paralell or series. It looks as if they are in series which means that however many batteris you connect in series they will still have the same voltage (in your case 1.5V). This means that in fact you dont need three batteries. The only way you would need three was if your original batteries were 4.5v and your new ones were connected in series.
The original batteries were 1.5v each, times three. Regardless of whether series or parallel increase the voltage, the old setup called for three 1.5v batteries, and he replaced them with three 1.5v batteries, so he did it properly.
Briguy9 f4ngu55 years ago
HAHA are you kidding? 1 AA batt = 1.5V, 1 old batt = 1.5V.

1.5V old batt x 3 = 4.5V
1.5V AA batt x 3 = 4.5V
It's grade school math, and so is this:
1.5V ≠ 4.5V, or
1.5V < 4.5V. They aren't the same, dude.

Oh yeah, Second Grade called, you're due for another year.
Ease up, he did the same thing many of us have done, misunderstood the OP and thought he meant 1.5v *total* for the old batteries. Be nice.
SimoMies f4ngu57 years ago
You are a complete moron. Learn electronics BEFORE start complaining. IF you put 3 AA batteries in series, that counts to 4.5V. Amps stays the same, just like blackghost informed. If you put them in parallel though, then it'll be still 1.5V but it'll last longer.
You winz
Yup. Second grade is calling Briguy9... lolz...
voltages in series add, amps stay the same
Mzege f4ngu57 years ago
why do u need a cigerate lighter?
dethmnky6665 years ago
i have a very limited spending range how much does all of this total?
I have tried to do this before and it broke my laser pointer. Overpowering the laser pointer will only make it break easier. not brighter,
The little laser pointer batteries are 1.5v and so are AA, AAA, C, and D
I used one D cell battery and it shined brighter for a split second and dimmed to nothing in about 3 more seconds
same happened with mine but it came back to life when i kept it in the freezer for a hour
That would be undepowering it not overpowering 3 * 1.5V = 4.5V
There is more to it than just voltage you know. A D cell has a whole lot more current than a button cell. Also it very unusual for something to be damaged from being under powered.
You'll probably need something like a 100k resistor depending on the original button cells.
Modeo (author)  gnasty gnork6 years ago
Yes overpowering will break it, however this instructable is to increase usable time of the laser by substituting longer lasting batteries at same voltage.
i had this crappy laser/led combo from a dollar store, and i took out the laser and put it in a pen and soldered it to a usb cable, and now its cool. its also way brighter and i can piss off kids in computer class.
You should do an 'ible on how to connect to a USB cable... I was thinking this would be useful for the professional doing powerpoint presentation and what not... You could connect the laser to your USB port of the Laptop from which you are hosting the presentation and never have to worry about batteries... Just make sure to give yourself some length on the cable so you can walk a little ways from the Laptop to present the material...
you could, but it would be easier to just use a 9 volt; no cords, less hassle.
I hate those "wal-mart, dollar store" laser pointers because every time i take one apart the laser diode and led if there magically vanishes as i open the case. by the way did you get detention from pissing kids off in computer class??? if not, your teacher rocks
No, shes pretty cool, but there was a sub that day. Me and my friend are at a 193% *shrug* so we had a laser fight on the rolly chairs. ;D
I got a $3.95 laser pointer and 2 white LED torch combo but the batteries are dead in just 1 week of pointing the funny red dot around the house.
the small cells which the laser module had be4 are now being replaced by much bigger longer lasting AA batteries. how much charge a battery can give out in its life (i think) is measured in mAh. those small cells have about 70mah, a duracell battery pumps out about 26000 mAh, i think, which will prolong the lasers run time :) . i have done this with all my lasers, i have broke a few but thats because i decided to encase it with hot glue to keep it still. i later found out that this glue is like 90*c when it comes out which is too much for the laser
awang8 chinnerz5 years ago
Wow... My hot glue is 170*c when it comes out of the kinda-ugly-when-you-think-about-it nozzle.
chinnerz awang85 years ago
170* thats kinda hot... you would kill the diode with that for sure XD
awang8 chinnerz5 years ago
I've never killed a thing with my hot glue...
chinnerz awang85 years ago
rly? wow...
cotton6 years ago
i flagged mmwag's comment as not nice because i hate that and great idea but show us how to build it while your building it
mmwag7 years ago
(removed by author or community request)
why cant you just read the "we havw a be nice comment policy" thing at the bottom of the thing while you are typing your reply because this is a great way to save money o batteries and if you had any knowlege at all on electronics (which you oviously dont) than you would know this is very easy to do
yeah!!!! u tell him
srhadaham mmwag6 years ago
He has a life. His life includes such activities as saving money by modding gadgets to run on cheaper batteries
mmwag dude, r u kidding me, this is a really good idea... if you dont wanna spend 5 bucks a piece for those small laser batteries, which only last like 3 hours maybe, you could do this. ill probably end up doing this
newkiraj mmwag7 years ago
really? i did it
you gotta have a hobby.
chinnerz6 years ago
because some lasers are about the size of one of those AA batteries( just a bit shorter ) what you could do is modd the battery holder so that the head of the laser sticks out. what i did was get some zip tie and clamped down the button, then i got a flick switch and put it behind the laser. if you want i can take a photo of the case ( without the laser (that was used for another project))
now doing this, will it make it more stronger to the point where it can burn things?
my lighter plug thingy is to big to fit can i just connect the wires from the bat. pack to it? ~struckbyanarrow
Modeo (author)  struckbyanarrow6 years ago
Sure then all you have to do is secure the laser to the battery pack in some fashion.
to make it burn things you have to solder something on the actual chip.
the chip that holds the diode or whatever. im gonna put an instructable up on it.
no the chip that controls the power spike
Power spike? are you talking about that teensy little black thing that is soldered on? Thats is called a surface mount resistor. And just so everyone knows, i DID end up trying to solder that little resistor. It doesnt work. I think it would just make it have alot more infrared light which could be EXTREMELY dangerous. When i tried it, the point was very dull and it was hard to make it show up. I WOULD STRONGLY ADVISE AGAINST IT. look at the safety page fror lasers on the internet... This is a hypothesis, about the IR, but i would still consider it a stupid thing to do.
power spike fo the laser the component u have to solder is the controller so the laser doesnt heat up =/
Think Again
Than i just mis-interpreted your message. I think we are talking about the same thing, the chip that the button is on in the laser that makes the light, there are a few things ( on dollar - store ones anyways ) the metallic strips making the actual diode, the resistor to solder that controls how much power actually goes to the diode, and the button that completes the circuit. when you push the button, the power goes through that resistor and the resistor " slows down " the power. If you Disable the resistor than you get the heat. BUT this only works with 5mW or higher GREEN laser Pens. The 5mW littlle laser pointers just get screwed up.
well it doesnt have to be green man
The actual laser has to be green. Like the light has to be green not the shell. and yes it does because the red ones just dont work.
why they dont work with red ones?!?! its the same theyre both lasers :P
I dont know why, the green ones just have more power to them
well but red ones are officially made for being stronger but its just 1mw as i mod it its stronger lolz and i did it today i writted in a piece of tape!
You can save some money on the 1.5V by purchasing (1) 12V battery. When you open the battery up you will find 8 1.5V batteries inside. A 12V runs about $2-3 and will save you some money in the long run.
LoneRanger7 years ago
Might I ask wat this modification does for the laser pen??? Is it just if u cant get them small ones or will the laser pen be stronger???? Idk good job tho
Well, anyone having cats and a dog that loves the laser toy can tell you that buying those little button batteries is expensive. I have LOTS of rechargeable AA batts, and can even charge "normal" alkaline ones. I hope this hack works because it sure would save money/make it easier to have the AAs around when you need them... it's hard finding the right size button batts.
bustedit Jumpin6 years ago
Why are the batts so expensive, when you can buy a complete cheapo laser w 3 new batts for a couple of bucks???
Myself Jumpin7 years ago
It just drives me nuts that they don't sell "Renewal" rechargeable alkalines anymore. They were perfect for laser pointers: Full per-cell voltage (1.5v as opposed to 1.2-1.3v for rechargeables) and very slow self-discharge. Putting NiMH AA's in a laser pointer is silly, they'll run flat from just sitting before you'll drain any significant power from them. A piece of dowel sized to fit the battery compartment is an easy way to do this. Drill a hole down the center, solder a wire to the pin of a thumbtack or the shank of a small copper nail, put it in the end of the dowel, and use that as your inner contact.
Jumpin Myself7 years ago
Clever. I just found my Renewal charger days ago, funny you should mention. Crikey, they're charged to like 1.6V. Yahoo! Have you heard of this charger: ECC charger by Saitek? I have it on permanent loan from a friend who "doesn't know how to work it"... ie doesn't have time to fig out and hates the annoying chiming when things can't be charged. This really does save cash on the batts and charges AA-Dcells, nothing smaller than an AA, although, I COULD probably modify it now that I am more emboldened by my recent electronics experiments.
Modeo (author)  LoneRanger7 years ago
It just extends battery life and changes the batteries from the button ones to regular AA's.
marc927 years ago
All the laser pointers that I have are very hard to access the insides. If you know of a brand for which that is not so I would be glad to learn of it.
bustedit marc926 years ago
We have an indoor fleamkt each weekend, and theres a booth full of cheap sht from china. i bought a toy laser gun for 3 bucks. It had a 1mw red laser pointer, 3 or 4 regular bulbs, plus a lil motor, and a sound chip IC (black blob) that says "peeww peeww fire fire!". The gun is plastic, and the laser comes out easily, very small and accessible. For the $3 spent I got a lot of stuff. I was thinking of buying up a box and parting out on ebay for bending n stuff. Go Sox. Good instructable!
DeriemD6 years ago
When I make it I will Hook it up to a car battery Mwhahaha
DeriemD DeriemD6 years ago
Sure it might destroy the laser pointer but there only a buck
f4ngu5...? if each battery is 1.5v and it originally takes 3, thats 4.5 volts. the same as 3 AA batteries. right?
Only if he has them in a series (one circuit). Yes, same as three 3 AA cells.
Use the reply button.
yeah it is but f4ngu5 has read as if each wasn't there....
dude !!!!! i love you man!!!!!!!!!
douro207 years ago
If you can find a laser pointer which takes two LR44 cells instead of three, you could buy a 1/3N lithium battery for about $5 and put it in there...it'll last longer than the LR44 cells.
yorniloc7 years ago
you no i made this into a laser cutter by titening the screw inside and soldering component b
butt you have to have a green laser
It's a good tip in general. Button cells are grand if you do need *really* small devices, but I've done the same thing to any number of devices including a laser pointer. With AA/AAAs being so much cheaper, it makes good sense to just solder something on, put a battery cage (can be raided from lots of broken AA/AAA devices), slap some duck tape on the SOB and you're good to go. For the ambitious, raid a DC port from another broken device and shove it in for good measure - run off adapter when you feel like it.

People who wish to run off a single AA might consider the voltage adapted LED flashlights. I always carry an LED flashlight that runs on a single AAA, stepping it up to 4.5 by my voltmeter. I'm not willing to destroy it, but I assume If I chopped out the led and soldered in wires, I could run an appropriate laser pointer off it. Perhaps I'll experiment, 'cos now I'm starting to itch a bit..
if you add too many batteries wont the laser get realy hot?
Modeo (author)  i make shooting things7 years ago
What normally happens is the circuitry will just fry do to current overload. If you are thinking about the really powerful lasers out there, yes, the units need cooling, because they generate heat as a byproduct of their intensity.
krazy7 years ago
could the laser pointer not be run on just 1 AA battery? If so why not just take one of those little flashlights and take the tip of the laser pointer and mod it to fit the flashlight... I think i might go out and buy some and see if i can get this to work.. because then you will still have the compact size and it look nice too.
Modeo (author)  krazy7 years ago
The way the resizing of batteries works is that you have to keep the voltages the same. The original 3 small batteries were 1.5 volts each for a total 4.5volts. The AA batteries are the same voltage 1.5 volts so you have to use 3 of them to match the voltage. If you have too low of a voltage the laser will not work, so you can't use 1 AA battery unless you redo the circuit controlling the laser.
tek20007 years ago
I have done something similar and much smaller and more compact before: Take one of those battery adapters and cut off a piece of the laser pointer back side so it fits into the AA battery case then take 3 more batteries and solder some cables to the contacts of the laserpointer. open one end of the battery case so the laser can get out. turn the pointer so that you can still operate the switch it works forever !!
DannyHunt7 years ago
Very cool for its ingenuity but sort of defeats the purpose of having a small laser pointer that fits in your pocket. Too big and clunky (ugly) for business, but I guess if it's just for your kids or pets around the house it will be just fine.
Modeo (author)  DannyHunt7 years ago
It still fits in my pockets. I wasn't thinking about its looks while building it, it was more of a practical issue. There are really nice laser pointers out there for the business class. There are also really powerful ones you can get here's a link:
http://www.amazing1.com/
ninja fire7 years ago
try putting like 120v to it will be like a 50W lazer thet can cut steel
Modeo (author)  ninja fire7 years ago
That would be nice, but then you wouldn't be able to buy it without signing a million papers, going through a military clearance and having the FBI investigate u. :-) ! If you change the voltage it will simply burn out the little laser diode, they are not meant for more power output.
DanAdamKOF7 years ago
How hard is it to work on the inside of a common cheap laser pointer? I dunno if I could reliably solder a wire to the battery content deep inside the one I have.
Modeo (author)  DanAdamKOF7 years ago
It's a bit tricky, there is 1 contact in the middle for the negative wire (this is the 1 that's the hardest) the other 1 u just solder to the side anywhere. It is due able with a little patience.
bigpinecone7 years ago
I WANT KOI!!!
JakeTobak7 years ago
He said what it does. It lets you use batteries that are cheaper and last longer than the normal batteries.