in Electronics, Experiment, Gear, Spectral Arts

Convert laser pointer to AA batteries

I play laser at the end of almost every day with my Border Collie, who is 1.5 yrs and has seemingly boundless energy.

My laser pointer is a strong Chinese (Taiwanese, actually, it turns out) number I bought years ago for some stupid reason. The green beam shoots really far and when its batteries are fresh, you can see the beam itself in dark or smoky air which is hella cool.

Anyway, it’s a problem because we play with it so often that the included CR2 battery wears out quickly. I bought a couple replacements, but it’s not sustainable. I already have a AA battery charger and batteries, so I figured why not try a conversion. It’s just about the level of DIY electronics that I’m ready for.

So I bought this 4 AA & 2 AA battery holder from Gikfun via for just under $10 CAD. I wasn’t really sure what I needed, and haven’t completely worked out the voltage/current question here, but I plunged forward recklessly just the same.

Here’s what I started out with for laser, disassembled:


The brass-y looking part (not sure if that’s actually brass) has a mark on it: with an ID number. I looked on the Taiwanese site but didn’t see it. It’s at least 10 yrs old though I think, so whatever.

Anyway, I watched some other confusing conversion videos and the process it turns out is actually really easier than I thought.

What I was able to get to work: use one alligator clip on the lower spring inside the laser case, and attach this to the black (negative) lead on the battery holder. Then attach the red lead to the case, since these kinds of cases are generally conductive and that completes the circuit.

Problem is that cuts out the build in switch and I don’t want an always-on laser, so I wired in an arcade button from Sparkfun which has been gathering dust as well. Wire the switch onto one of your leads, and then to the case. I’m not sure if you can do it off the black lead, but probably, right?

Anyway, once I got that working, I hunted around for a small box to use as an enclosure.

If I’m able, I will find myself an old NES zapper and gut it to use as a housing.

But this was a really fun, easy project with minimal parts requirements. What’s even more fun is that this laser seems more powerful than before even, and I can just recharge everything at my convenience. Will also work with a small dollar store style red laser like for cats.

Once I test this out in the field a few days, I will replace probably my alligator clips with a little soldering. But I need to find a great enclosure first!

Also published on Medium.

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