Laser pointer modification by Modeo
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
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cochrate says: Mar 4, 2009. 2:27 PM
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
maniacse says: Jun 8, 2012. 1:49 AM
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.
ronaln304 says: Oct 26, 2009. 10:00 PM
or the another way of power is to plug it in your usb port on you computer. it is 4.5 volts
srhadaham says: Dec 3, 2009. 12:31 PM
Good idea, but I'm pretty sure usb is 5 volts, I could be wrong though
maniacse says: Jun 8, 2012. 1:34 AM
Yes, it is 5V. But, when I play with my dog, my PC/laptop rest home.. So, nice idea, but for other use..
f4ngu5 says: Mar 24, 2007. 11:50 PM
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.
Project D says: Feb 2, 2011. 2:19 AM
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 says: Jul 16, 2009. 6:59 PM
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.
Project D says: Feb 2, 2011. 2:16 AM
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 says: Sep 19, 2007. 11:52 AM
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.
srhadaham says: Dec 3, 2008. 12:34 PM
You winz
cowscankill says: Sep 19, 2009. 8:57 AM
Yup. Second grade is calling Briguy9... lolz...
blackghost says: Jun 17, 2007. 1:19 AM
voltages in series add, amps stay the same
Mzege says: May 10, 2007. 3:22 AM
why do u need a cigerate lighter?
dethmnky666 says: May 5, 2009. 9:30 AM
i have a very limited spending range how much does all of this total?
gnasty gnork says: Feb 16, 2008. 3:42 PM
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,
Davvik says: Sep 3, 2008. 7:06 PM
The little laser pointer batteries are 1.5v and so are AA, AAA, C, and D
gnasty gnork says: Sep 4, 2008. 12:37 PM
I used one D cell battery and it shined brighter for a split second and dimmed to nothing in about 3 more seconds
sjs229 says: Feb 9, 2009. 12:17 AM
same happened with mine but it came back to life when i kept it in the freezer for a hour
srhadaham says: Dec 3, 2008. 12:29 PM
That would be undepowering it not overpowering 3 * 1.5V = 4.5V
cornflaker says: Dec 19, 2008. 9:39 PM
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.
awang8 says: Dec 22, 2008. 2:25 AM
You'll probably need something like a 100k resistor depending on the original button cells.
chinnerz says: Aug 23, 2008. 3:09 AM
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 says: Dec 22, 2008. 2:26 AM
Wow... My hot glue is 170*c when it comes out of the kinda-ugly-when-you-think-about-it nozzle.
chinnerz says: Dec 24, 2008. 2:03 AM
170* thats kinda hot... you would kill the diode with that for sure XD
awang8 says: Dec 25, 2008. 8:35 PM
I've never killed a thing with my hot glue...
chinnerz says: Dec 26, 2008. 12:25 AM
rly? wow...
Modeo (author) says: Aug 22, 2008. 9:53 PM
Yes overpowering will break it, however this instructable is to increase usable time of the laser by substituting longer lasting batteries at same voltage.
peanutthegreat says: Oct 8, 2008. 6:17 PM
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.
DV8Ways says: Jan 8, 2009. 1:14 PM
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...
peanutthegreat says: Jan 10, 2009. 9:52 PM
you could, but it would be easier to just use a 9 volt; no cords, less hassle.
gnasty gnork says: Oct 10, 2008. 2:00 PM
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
peanutthegreat says: Oct 11, 2008. 10:40 AM
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
awang8 says: Dec 22, 2008. 2:28 AM
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.
cotton says: Dec 5, 2008. 8:05 AM
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
mmwag says: Mar 19, 2007. 5:58 AM
(removed by author or community request)
srhadaham says: Dec 3, 2008. 12:35 PM
He has a life. His life includes such activities as saving money by modding gadgets to run on cheaper batteries
alanfreefal says: Jul 24, 2007. 7:48 PM
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 says: Jul 20, 2007. 10:40 AM
really? i did it
seedofanarchy says: May 6, 2007. 12:53 PM
you gotta have a hobby.
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