Anyone tried this 20mW DX laser?

http://www.dealextreme.com/details.dx/sku.8787

I've been looking at this one for quite a while now.. It looks very nice. I have two flashlights looking exactly like that but a different color and want to turn them into lasers anyway..

If anyone has it and can compare it to another one, or even measure it, that would be great.

The laser seems to have two nice aluminum heatsinks on the module, that make it fit into the flashlight head. The only problem with it would seem to be the stupid battery they used. 4xLR44 coin cells in one 6V battery. It means it only works for 5 minutes.


The host they used is capable of taking an AA sized battery, but part of the module and the driver with the spring use up half of the battery tube and don't allow you to put an AA size Li-Ion in. Someone tried powering it with 3 1.5V batteries, with no drop in brightness, and with two AAA cells it is supposed to be as bright as a DX30. Could even have current regulation, that drops out somewhere above 3V. This could be a great little laser, if it wasn't for the stupid battery, but i think it would work nice from a Li-Ion cell. The driver looks very similar to the CR2 30mW "flashlight" style DX laser (like KD50).


I have some 1/2AA Li-Ions from AW on CPF, and i'm sure they would fit, and probably make it work for around an hour.

I can't stop thinking about ordering it.. : If only it was a bit more powerful.

I too have looked at this, but didnt get it because of the battery.
There arent rechargable batteries for this are there?

I can only imagine how often the battery runs out and how expensive replacements will be. so i just went with the mini 30mW laser which is pretty small and thats a cr123a.

mikeeey said:

I too have looked at this, but didnt get it because of the battery.
There arent rechargable batteries for this are there?

I can only imagine how often the battery runs out and how expensive replacements will be. so i just went with the mini 30mW laser which is pretty small and thats a cr123a.

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The original battery only lasts 5 minutes and there is no rechargable battery of the same type.


But i do have rechargable Li-Ions, that are as wide as an AA and only half the length, with 250mAh capacity (actual, not Ultrafire capacity). They would fit in there, because it is an 1xAA flashlight host, except that the module and the driver take up half of the battery tube.

The 1/2AA Li-Ions are slightly smaller than CR2s, and i'm pretty sure they would work great in this laser. If not, i could replace the driver to bring it up to full strength and with a constant current over the entire battery voltage range. But i don't think it's necessary, as it would seem to be regulated. There is no difference in brightness between 4.5 and 6V. At 3V it drops in brightness a little and is supposed to be as bright as the 30mW DX pen laser.


With rechargable batteries, i don't really care about the runtime. Besides, it would be around 1 hour with 14250 (1/2AA) Li-Ions.

You guys could always buy these to go with it.
50 LR44's for $4.

Looks like a cool laser.

Razako said:

You guys could always buy these to go with it.
50 LR44's for $4.

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Nice! That would be 50 times 5 minutes! That's four hours of non stop fun (and battery changing). ;D

No, seriously.. If an 1/2AA Li-Ion fits, why not use that. It also costs $4, but will only have to be recharged 4 times in the same four hours of "non-stop" fun..


This is a really nice looking laser, and could be a great product for resale, if only it didn't use such a stupid battery. I mean 5 minutes run time.. I could never sell a product like that. I would have to include two 14250s and a charger, just to feel good.



EDIT: Oh, wait, those are single LR44 batteries. The laser is supposed to use four of them, but works just as well on three. So it would be 13 times 5 minutes of fun. The fourth battery would seem to be just transformed into heat by the driver.

Using these batteries in a 20mW red would still make sense, but not in a 20mW green, which requires 100-200mW of IR. There is a bullet keychain green on DX, using these tiny batteries, and it also doesn't last long. The nice host in the picture above is capable of much more. It could easily do 50mW of green with a better module and the 14250.

I have this one. I had ordered 3 pieces 9 months ago, still working. http://www.dealextreme.com/details.dx/sku.5785

The laser you are talking about will consume the batteries very quickly. You will always have to change the batteries.

beachbumbora said:

The laser you are talking about will consume the batteries very quickly. You will always have to change the batteries.

Click to expand...

That is why i'm talking about using a different battery, that would make it work for at least an hour! Instead of the crappy 4x coin cell battery, i would use an 1/2AA size Li-Ion.


I just want to know if anyone has one of these, to see if it actually puts out a decent enough amount of green (during the 5 minutes it works) to be worth it.

I see.

iss it possible to just mod it and insert one cr2 or maybe a AAA in it?

No, a CR2 doesn't fit. It's too wide. I tried with the identical flashlight host. A CR2 is 15260.
But a 14250 would definitelly fit! An 14250 has the diameter of an AA and half the length. An AA is 14500.

The numbers 14250 mean 14mm diameter, 25mm length and the 0 means a round cell.
In fact, as i explained above, the flashlight host is capable of accepting an AA cell, but part of the module and the driver are sticking down the battery tube. Even if the driver was removed and replaced by a flat one, without a spring, an AA still wouldn't fit.

But an 1/2AA would fit without any modifications, and this battery is a regular item, $4 a piece, high quality Li-Ion from AW.


I have some weirder battery sizes: 10280 - 2/3AAA, 10220 - 1/2AAA, 10180 - 2/5AAA and so on. I got those for some micro lasers i want to make.

But the 1/2AA battery is nothing special, and is just a little bit smaller than a CR2, so you can actually use two 1/2AA batteries in an 1xAA flashlight host together with a regular 317 driver to get a tiny but powerful laser.

dude those are some rare sizes....why do they even make them!! if the market was all standarized to AA it'd be awesome (maybe there's some magical explanation which will be explained by some LPF god right below my post :wink

What? You think it would be awesome, if all batteries would be in AA size? How would you like having to use a cell phone with three AA batteries on the back side?

There are many different STANDARD battery shapes and sizes. And that is good, so that not all devices have to have the same shape and size. Imagine making a blue ray laser and having to use three AA size Li-Ions to power it. Would you want such a huge laser, when it could just as well be only half the size or even smaller but still have the same power?


Some of the battery sizes i mentioned really are small. But the 2/3AAA will for example allow me to use a 2xAAA pen laser body for a Blue Ray laser, because three of them will fit into the tube, and a normal 317 regulator will be able to work with them.

Using two 1/2AAA batteries, i could make a burning laser out of an 1AAA laser pointer body, again with a normal 317 regulator. Two 1/2AAs would fit into an 1xAA flashlight host, which looks exactly like the picture above, and would again allow the use of a 317 for driving the laser.

With a buck/boost driver only one of these small cells could be used to power ANY diode and would make the tiniest possible laser.


I love having different battery shapes and sizes, especially the rare ones, because they give me possibilities i would otherwise not have.



Oh, and some of these rare sizes were custom made to order, and are not otherwise regularly available.. Someone needed them that small and had them made in a huge quantity.

If a half-AA cell fits, i guess you're done. In terms of voltage it should be fine - those button cells are rated 1.5 volts each, but under such load that'll drop to 1 volt or so in a split second.

I've never seen a 1/2 AA lithium cell, but i guess they are comparable to CR2 in terms of capacity and internal resistance - should deliver a lot more than 3 of those button cells.

I completely forgot about the battery sag. A laser like this probably pulls 150-200mA if not more. And they are using coin cells.... :

If it should turn out not to be regulated, an 1/2AA Li-Ion could actualy kill it, cos it wouldn't sag.

But after your review of the 30mW DX laser, that looks like a KD50, i decided not to buy this. That one is definitely a better choice.


Yeah, they look almost exactly the same as CR2s, but are a little bit shorter and thinner. The capacity is 71% of a CR2.
They would make for an easy red laser solution in 1xAA flashlight hosts. I wanted to use them in the host that looks exactly like the laser in the picture above.