newbie keychain question

I've read the boards on here for awhile, and decided to finally jump in. I have carried my fenix p1d on my keychain for a year or so, upgraded to the -ce then the q5. I carried a simple 5mm pushbutton from DX before that, and am considering going back to that just for my keys.

Has anyone tried upgrading the 10mm keychain they sell to a brighter 10mm LED? I have looked on ebay and they have 3 10mm led's that seem to upgrade the 20,000mcd that comes with it. Which one would work best, the 140,000mcd, a 1/2 watt 280,000 mcd ( 13 lumens advertised ), and a one watt 61 lumens advertised. the keychain comes with 2 cr2025 3 volt lithiums, and appears to have 150mah or so. since these are so cheap to buy ( 73 cents apiece shipped ) I am ok with minimal run time.

It would appear that the 1/2 watt would still have about an hour of run time if it draws 150ma. the 140k draws 20ma. both of these led's are cheap to buy too, at around 30-40 cents or so apiece I'm ok overdriving them. My gut tells me the 1 watt version ( 4-5 bucks each ) at 300ma will fry the batteries too quickly unless I go to a larger cr2050 cell. then the voltage will be too low. these led's seem to just rest inside the case. has anyone tried this, and what problems or solutions do you see ? am i right on most counts, and what have I got wrong? is this a bad idea? or a good baby step to begin modding?

You might want to consider these
http://www.dealextreme.com/details.dx/sku.12270

I personally hate the beam pattern on the 10mm keychains, and they are too bulky.

I looked at the 5mm 35k ones, and that's why I was considering swapping out the 140k mcd or the 280k mcd on the 10mm's . the 140k replacement has a pretty narrow beam ( 12 degree) but the 280k had a 40 degree. I'm trying to minimize the bulk in my pocket from the p1d on my chain, it also hits my leg while I am driving. the 10mm keychain seems to be about 30% bigger than the 5mm. I can live with that. of course I'd love the orb or the wee, but I am interested in trying to upgrade something...

Thought of another reason today to go in the keychain direction. On my keys now, the fenix p1d-ce q5 is doing the same thing my old p1 did. the ring /lobster claw combo is slowly ripping it's way through the aluminum hole in the bottom of the flashlight. I can always drill another hole in the cross on the bottom, but the problem remains.

Keep in mind, mcd is a measure of the hotpot/throw only, not overall brightness.

so, 140,000 mcd will not be brighter than 20,000mcd? I know that lumens is a basic brightness level, and the 280,000 mcd ( 1/2 watt ) are rated at 13 lumens.

The Nichia GS overdriven in a fauxton will be brighter than pretty much anything else in that form factor. Generally, you can't relate mcd and lumens anymore than you can relate lux and lumens.

ok, I guess I always equated more is more, whenever your talking mcd to mcd, lux to lux or lumens to lumens. I guess what I don't understand is how an led rated at 35000mcd is brighter than one at 140,000mcd. Is it because the voltage/ma makes the 35k brighter? or the degree angle? i admit I'm a newbie. :duh2:

David Gretzmier said:

ok, I guess I always equated more is more, whenever your talking mcd to mcd, lux to lux or lumens to lumens. I guess what I don't understand is how an led rated at 35000mcd is brighter than one at 140,000mcd. Is it because the voltage/ma makes the 35k brighter? or the degree angle? i admit I'm a newbie. :duh2:

Click to expand...

It's degree angle essentially. If you focus a little bit of light into a tight beam, you have a high mcd/lux reading. You can take a lot more light and shine it over a wide area, and have a very low mcd/lux reading because the light is more spread out.

David Gretzmier said:

I looked at the 5mm 35k ones, and that's why I was considering swapping out the 140k mcd or the 280k mcd on the 10mm's . the 140k replacement has a pretty narrow beam ( 12 degree) but the 280k had a 40 degree.

Click to expand...

I detect some marketing BS. A wider angle LED will invariably (in reality) have a LOWER Candela -- 280 Cd into 40 degrees is by definition about 100 lumens. You should basically disregard advertized Candela numbers as most ebay vendors assume their customers don't know the actual meaning, and simply lie and make up something that sounds bigger and better. I'm sure that's also why they refer to intensity as "250,000 mCd", intead of 250Cd. Yet nobody would EVER describe a length of 250 meters as 250,000 millimeters...

I'm trying to minimize the bulk in my pocket from the p1d on my chain, it also hits my leg while I am driving. the 10mm keychain seems to be about 30% bigger than the 5mm. I can live with that. of course I'd love the orb or the wee, but I am interested in trying to upgrade something...

Click to expand...

The 10mm LEds are a waste of space/poor design, and have a less useful beam pattern than the 5mm LED keychain lights. Although if you're trying to cut down bulk but dont' want to give up the raw output and/or throw of your P1D, have you considered a AAA light?

The p1d is a great show off light, but in reality it is too much for a keychain for me. The lanyard hole gave up the ghost today anyway. I either need to drill another hole or go to a different light for my keychain.

lengthwise, the AAA light sounds interesting, but probably lengthwise the same as p1d. but diameter wise I would think much less. I really only need one level of bright and probably 60-80 lumens would do me. I just want something that is like 4 times as bright as the fauxtons from dx, and not as big as the p1d. any ideas?

Did you consider the Nichia GS faux-tons?

Because I don't think that the 10mm leds are any brighter than the 5mm ones.

Also if you're looking for another light to put on your keyring I would suggest something in the AAA size. Fenix has the L0D-Q4 which is very popular but there are other brands availible.

I've ordered a couple of the 35k nichia fauxtons. I have a discontinued older cr2 dx light that is labeled smartfire b-13w, it's output is less, but similar to the medium on the p1-d ce Q5. probably 60 lumens or so. I'm pretty sure this is an old luxeon III or so. sizewise it is pretty close to perfect. I'd like to mod it to a cree r2, or find an r2 cree twisty that runs a cr2 that is that size or smaller.

the aaa lights seem to run thinner, but longer in length , which for me on keychain still hits my leg when I drive. so 2" long is max. the perfect light is probably the new orb raw aluminum at 100 bucks, or the wee at 80 or so. Surely there is a less expensive mass market twisty light ( 25 bucks? 40 bucks? ) out there that runs a newer led and a cr2. but I have not found it.

the other issue is putting it on my keychain itself. It seems putting a tiny ring through the lanyard hole and carrying these lights on a keychain wears out the aluminum hole fast. I doubt my cr2 twisty will last much more than 3 months or so before rubbing through. any ideas?

One of these shouldn't wear out the keychain hole:

http://www.dealextreme.com/details.dx/sku.3249
http://www.dealextreme.com/details.dx/sku.11669
http://www.dealextreme.com/details.dx/sku.5397

I used to carry a Fenix P1D-CE on my keychain and found it to be a little big. I ordered a Fenix L0D-CE Q4 Olive which never turned up . That must have got stolen by someone in the postal service, so, instead, I decided to go for something even smaller...


The light on the left of a typical squeeze-type keychain light, to the right is the Cree Q5 equipped Lummi Wee NS

MikeSalt said:

I used to carry a Fenix P1D-CE on my keychain and found it to be a little big. I ordered a Fenix L0D-CE Q4 Olive which never turned up . That must have got stolen by someone in the postal service, so, instead, I decided to go for something even smaller...


The light on the left of a typical squeeze-type keychain light, to the right is the Cree Q5 equipped Lummi Wee NS

Click to expand...

It's good unless you need something with decent runtime and lumens. Although it is impressive that you can get about 50 lumens outta that thing for about 30mins.

I've been doing all I can to resist buying a Wee, just because they're so darn cute and well made. Maybe someone will sell me one cheap when the new Wee-Da's appear...

You gotta love the wee, or the raw. both are the ultimate show off lights. I am looking for something about that size, but 1/2 the power and price.