Replacing XP-G with XM-L?

I just purchased a very cheep flashlight, about the cheapest you can find, $5. It is a small no-brand light that has an XP-G LED. The output of the light is very impressive. I would say that it is about 200lm (that's just comparing it to one of my nice flashlights).

Just for fun I would like to try to swap out the XP-G for an XM-L.
I found an XM-L that looks like it could just be "dropped in," it has the same oporating voltage, and the current is higher than the XP-G so it wouldn't get burned out or anything.

Here is a link to the light that is in my flashlight: http://www.digikey.com/product-detail/en/XPGWHT-01-0000-00FE3/XPGWHT-01-0000-00FE3CT-ND/2242664
And here is a link to the light that I would like to get: http://www.digikey.com/product-deta...0LT40E4/XMLAWT-00-0000-000LT40E4CT-ND/2615395
(I do not think I am breaking the rules by posting those links, but if I am I will remove them)

Has anyone done this? --Thank you!

My $5 light!

The question is, how large is the hole at the bottom of the reflector that the emitter sits behind? If the hole is slightly larger than the XP-G then an XM-L won't work as its a but larger than an XP-G. If he hole is larger then you might be able to get away with it, but, you might run into focus issues with your reflector.

The question is whether or not you're going to like the resulting beam. The XM-L has a larger die which will give you a larger hotspot that is slightly less intense and the spill will be slightly brighter. The output will increase by about 40 lumens, but, you might not even notice the difference in brightness since it's mostly in the larger hotspot.

PCC said:

The question is, how large is the hole at the bottom of the reflector that the emitter sits behind?

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Sorry not to clarify earlier, but the light uses a little lens, not a reflector. The beampattern is already so bad I don't think it could get much worse! When the light is "zoomed" you can see the square LED on the wall:fail:. So to answer your question, there is no hole that the LED would have to fit into.

It's an aspheric lense, you will always see the 'square' image of the LED die on the wall at full focus, whatever LED you use.

Also, an XM-L with it's wider emission angle would waste a lot more light, less would make it out of the lense. The lower surface brightness will also mean less throw.

It is indeed an aspheric lens, which means there is no true focus, but again, this is a $5 light and I'm not expecting much with it. Honestly, I bought it for a laser build, but the 14500 can't support a 1.5w diode. And anything I use this light for will be up close work - like on a car or something, so I do not require, nor want much throw.

And the XM-L that I will get (in the link) has the same angle as the XP-G that I am replacing, so I don't thing there should be much of a problem there.

Ok, you might want to consider potting the head (not essential) and leaving it as a bare LED/'mule' light for full flood. That aspheric lense design is already very inefficient for getting light OTF for XP series LEDs.

Btw, are you sure it's an XP-G and not an XP-E? I can't tell very well from the picture but it looks slightly more like an XP-E to me which has a slightly smaller viewing angle.

The listing I bought it from said that it was an XP-G LED, and it does look like the ones in my TK45 and PD30, but I am not 100% sure that it is.

And forgive me if this is a stupid question, but what is "potting" and how would it help? Digkey sells lenses for XM-L emitters (http://www.digikey.com/scripts/dkse...ewproducts=0&ptm=0&fid=0&quantity=0&PV309=653) could I drop one of those into the build in replace of the current one?

Potting is filling a space with a substance, which will then set, in order to electrically insulate it. In relation to your light it would mean putting glue or something similar around the LED and over the solder connections to keep it waterproof. It isn't essential, but could be beneficial.

The way to tell between XP-E and G is the size of the yellow die in the centre. If there is any gap between the edge of the yellow bit and the edge of the clear dome then it is probably an XP-E.

A new lense may work, it depends entirely on whether it would fit in the space available.

From the pic, it looks like the original poster's flashlight is a clone of a Sipik 68, a small 1xAA/14500 budget zoomable light.

Yes, you can replace the emitter with an XM-L. At high currents this should give a noticeably brighter flood mode. Spot mode will be wider and not project nearly as far. If you really want to see what an XM-L can do in an aspheric you'll need to replace the driver with a higher current one (2.8 amps works well) and run it on IMR cells.

Forget making the light waterproof. The Sipik 68 and clones do have slots for o-rings so in theory you could make it waterproof by sticking in appropriate size o-rings in them. However, in practice this does not work well with a push-pull style zoom mechanism. This is because cycling the zoom mechanism changes the internal volume of the light which will reduce or increase the internal air pressure relative to the exterior. If the light is airtight, the air pressure won't be able to equalize. The result is that the zoom mechanism won't stay in position and becomes unusable. Example: With an airtight SK68, if you seal the light by putting in the batteries in flood mode, then the zoom mechanism will seek to return to flood mode on its own. If you slide the bezel into spot mode, air pressure will cause the bezel to retract on its own back to flood mode.

The existing lense that comes with the SK69 will work fine for pretty much any emitter. However, you may want to modify the body or add spacers around the pill threads so that the zoom mechanism stops at the optimum point.

RedForest UK said:

I...

Also, an XM-L with it's wider emission angle would waste a lot more light, less would make it out of the lense. The lower surface brightness will also mean less throw.

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you can get around this by modding the light so that the top of the emitter sits as close to the back of the aspheric lens as possible. The closer the emitter is to the lens, the wider the flood with less lumens wasted into the side of the bezel. Of course spot mode still wastes a lot of lumens though.

RedForest UK said:

Potting is filling a space with a substance, which will then set, in order to electrically insulate it. In relation to your light it would mean putting glue or something similar around the LED and over the solder connections to keep it waterproof. It isn't essential, but could be beneficial..

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My understanding is that potting is usually done with the driver electronics. You can place a non-conductive material such as arctic alumina epoxy over the electronics. The main effect is to provide additional support for the wiring and increase its resistance to shock from being dropped.

Personally, I prefer unpotted electronics as it is much easier to mod. It's easy to swap the driver on an unpotted light. Not so with a potted light.

Fireclaw18 said:

From the pic, it looks like the original poster's flashlight is a clone of a Sipik 68, a small 1xAA/14500 budget zoomable light.

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Geeze, how could you tell from that photo? The light is a clone of a Sipik 68. I am running it with a 14500.

Fireclaw18 said:

Yes, you can replace the emitter with an XM-L. At high currents this should give a noticeably brighter flood mode. Spot mode will be wider and not project nearly as far. If you really want to see what an XM-L can do in an aspheric you'll need to replace the driver with a higher current one (2.8 amps works well) and run it on IMR cells.

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Looks like people on eBay sell XM-L mounted on drivers. It sure would be easy to drop in something like this, I bet I could get 500lm from it - http://www.ebay.com/itm/CREE-XM-L-T...291?pt=LH_DefaultDomain_0&hash=item3a74f5fceb.

I could have bought an XM-L light for $16, but this should be much more fun, and it is very small. The only problem is that an XM-L will use about 10watts... an IMR 14500 is 700mAh... 700mAh/10watt/3.7volts = 15minutes I'm not sure a 14500 could handle that draw. I guess I'll find out.

weegidy said:

Geeze, how could you tell from that photo? The light is a clone of a Sipik 68. I am running it with a 14500.



Looks like people on eBay sell XM-L mounted on drivers. It sure would be easy to drop in something like this, I bet I could get 500lm from it - http://www.ebay.com/itm/CREE-XM-L-T...291?pt=LH_DefaultDomain_0&hash=item3a74f5fceb.

I could have bought an XM-L light for $16, but this should be much more fun, and it is very small. The only problem is that an XM-L will use about 10watts... an IMR 14500 is 700mAh... 700mAh/10watt/3.7volts = 15minutes I'm not sure a 14500 could handle that draw. I guess I'll find out.

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IMR 14500 can handle around 5 amps draw. It should have no problem handling an XM-L even with a 2.8 amp driver. However, a protected ICR 14500 can only handle around 1.5 amps safely. So you would be stressing your battery if you are not using an IMR cell.

Heatsinking may be an issue. The SK68 is really too small to run at 2.8 amps for an extended period of time. Be sure to only run your light at full power for short periods of time at 2.8 amps.

An XM-L "can" replace that of an XP-G emitter. You'll have to thermal epoxy it on but make sure you have the right sized MPCB board. As for the light itself, I have a feeling they used a cheap 800mah driver that starts on High>Low>Strobe. I got rid of this problem by custom-fitting a aluminum ring into the bezel and then pressing in the driver. Solder everything together and VOLA!!! Your customer is happy but your wallet isn't as it was a free service.

Are you saying that the company that made my $5 flashlight used a cheep driver? I'm sure they did, and I'm sure the one I just got on eBay isn't any FourSevens driver either. But for a total of $16 I'd say this is going to be a pretty good light. The one thing this light does have going for it is the heatsinks, they seem pretty good.

I ordered an XM-L U2, and a 2800mA driver. I should be able to get very close to 1000lm with this set up.

I did add some o-rings, and I replaced the rubber on the switch with a spare from a fenix light of mine. I will definitely do a write up when I get the XM-L (which should be in about 2 to 3weeks).

weegidy said:

I ordered an XM-L U2, and a 2800mA driver. I should be able to get very close to 1000lm with this set up.

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Are you sure it is 1000 lumens at the emitter or OTF? Once behind an aspheric, you lose quite some percent of the lumens OTF.

When the driver does come, you may need to custom-make a pill to fit the driver on and the pill fitted into the bezel as well. Unless, the hole is measured to 16.92mm in diameter.

Tiresius said:

Are you sure it is 1000 lumens at the emitter or OTF? Once behind an aspheric, you lose quite some percent of the lumens OTF.

When the driver does come, you may need to custom-make a pill to fit the driver on and the pill fitted into the bezel as well. Unless, the hole is measured to 16.92mm in diameter.

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The LED should emit close to 1000lm, so probably 800lm when it's all said and done. I might see if I can fit a little parabolic reflector and glass lens in there instead of the plastic aspheric lens - that would probably boost the OTF luminosity by quite a lot.

As for the driver and LED module I ordered they are both 16mm, the same as the old LED module and driver that were installed. It should be pretty much a plug-and-play conversion.

Here are the items I ordered
-LED: http://www.ebay.com/itm/321012846528?ssPageName=STRK:MEBOFFX:IT&_trksid=p3984.m1427.l2649
-Driver: http://www.ebay.com/itm/261031758625?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

And here's what I took out of the light

most lights that run at 2.8a with XM-L U2 usually gets about 800+ if behind a reflector setup. But the driver in the list is 2.5a.

Tiresius said:

most lights that run at 2.8a with XM-L U2 usually gets about 800+ if behind a reflector setup. But the driver in the list is 2.5a.

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Thanks for the info. This is my first flashlight "build" so to speak. 2.5amp should be OK especially since it is such a little light. Maybe 600lm+ or so?

weegidy said:

-Driver: http://www.ebay.com/itm/261031758625?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

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Could I modify the driver to output 3.0amps (so I can get full 1100lm at the emitter)? Would it be as simple as replacing the resistor, or do the ICs control the current? I can't find the specs for the ICs on the board, but I am guessing that the resistor sets some sort of setting on the IC that controls the current. Can anyone confirm or deny that? -_- I'm a huge noob to drivers.

Thanks!

weegidy said:

Could I modify the driver to output 3.0amps? Would it be as simple as replacing the resistor, or do the ICs control the current? -_- I'm a huge noob to drivers.Thanks!

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I'm a bigger noob than you are when it comes to modding drivers. I would try the setup with what you have as of now to see if the light can dissipate heat properly. You might need to ask the guys at the flashlight electronics section about modding drivers. But definitely put together what you have now and if you think it's possible to push harder without frying the LED, go for it.

Remember, safety first before anything else.