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.
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pcanywii3 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.
ronaln3044 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 f4ngu56 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...
cotton5 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 mmwag5 years ago
He has a life. His life includes such activities as saving money by modding gadgets to run on cheaper batteries
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