Slashdot Mirror

http://www.candlepowerforums.com/vb/showthread.php?431016-Another-pocket-fireworks!-(or-why-you-shouldn-t-carry-a-loose-lithium-battery)

http://www.candlepowerforums.com/vb/showthread.php?262234-TK-Monster-Explosion

These were 18650 cells.

http://www.candlepowerforums.com/vb/showthread.php?431016-Another-pocket-fireworks!-(or-why-you-shouldn-t-carry-a-loose-lithium-battery)

http://www.candlepowerforums.com/vb/showthread.php?262234-TK-Monster-Explosion

These were 18650 cells.

A few years ago I was exactly like you. Even now, I still very much agree with you in 'spirit', and perhaps in the VERY long term (1000-10000+ years) evolution may fix the 'bug' which stops your argument from making perfect sense.

This 'bug' is that blue light affects melatonin production (decreases it, so it's harder to get to sleep). This isn't something you can get around. Subjectively, it could also be said that orangey hues (even more red than incandescent!) look 'cosier' and are a nice contrast to the day's blue light. Due to the nature of qualia, that's almost impossible to disprove. Heck, even green and blue illumination is a nice change occasionally.

Yours though is the first comment I've read in my life that even goes in this direction though, so I think that's awesome in itself. You might be interested in my post at CandlePowerForums which tried to find out what colour temperature is subjectively closest to pure white: http://www.candlepowerforums.c...

While I'd like to switch over to more LEDs, every LED bulb I have purchased so far has had manufacturer instructions that they should NOT be mounted in an enclosed fixture (such as a ceiling dome).

The latest 40w and 60w equivalents from CREE are fine in an enclosed fixture as long as there are no incandescents in there with them.

http://www.candlepowerforums.com/vb/showthread.php?374881-40w-led-s-inside-a-ceiling-fixture

No, the R stands for Round, and designates that it's a cylindrical cell. The 0 is just the tenths place, denoting that the cell is 65.0 mm long. I'm sick of this misconception (spread memetically through and from candlepowerforums), could you people please get it right?

No it doesn't. Of course that depends on your definition of "works". If you define it as creating a least common denominator of LOLcats and drunken party pictures, then yes. It has to be popular. OTOH, if you define it as people with particular interests creating online forums to discuss their interests, and possibly meet up in real life then NO, it doesn't have to be popular. There were forums for hair styles, flashlights, trains, motorcycles and a bazillion other things before FaceBook. They are still there, slogging it out, losing a bit of membership but never really going away. They'll still be there if FaceBook gets MySpaced. They "work" for the people that are on them.

Oh, and Slashdot? Popular? Sort of. Not as popular as FaceBook; but not as obscure as candlepower forums. I suppose all of these things "work". All your friends from school are not on all your interest-based forums. You know what? That's a good thing.

How many $20 LED lamps have you bought? How many $10 ones? ALL SHIT.

Cree makes good bulbs because they are driving demand for their LEDs - Cree and Philips are probably neck-and-neck for the lead position in the LED market.

They've got a 40-watt equivalent for $10 at Home Depot and a 60-watt for $14.

http://www.candlepowerforums.com/vb/showthread.php?356710-Cree-A19-9-5w-60w-800lm-2700K-for-13-97

...seems to have the expert analysis. Some people are into flashlights so much and the LEDs that may be used in them, it's crazy what details they keep tabs on.

Post on the Cree MK-R LED at Candlepower Forums.

Nope, lithium primary cells are quite capable of failing explosively. In fact, I think in some ways they're more dangerous than lithium ion batteries because they contain elemental lithium in normal operation. Button cells are probably small enough and rigid enough to be reasonably safe, other lithium cells not so much.

Actually, at high loads, NiMH batteries have nearly double the capacity of alkalines.

Take a look at this review for some AAA-powered flashlights:

http://www.candlepowerforums.com/vb/showthread.php?240639-ITP-A3-EOS-amp-Maratac-AAA-Reviews-RUNTIMES-BEAMSHOTS-DETAILED-PICS-amp-more!

Here's the time-until-50% for three kinds of batteries:

Alkaline (brand not mentioned): 34 minutes
NiMH (Sanyo Eneloop): 59 minutes
Lithium (Energizer L92): 87 minutes

So why haven't you done it?

CPF has a large community of flashlight geeks. Some of them have been at it a long time and are very competent (see McGizmo), but there isn't really anything like what this guy proposes.

Building a suitable housing and mating a good switch and reflector and emitter and driver and lens and power source, have all been done many times over. There is a lack of good, readily programmable, software. Making the thing blink in different patterns is not exactly rocket science, but a few clicks to customize the way the driver manages light output in response to voltage gets my flashlight geek endorphins flowing.

A perfect example of how Mag hasn't done any innovation or design work since the creation of their original lights.

How the FUCK can you have a gigantic chunk of aluminum and fuck up your thermal management so badly that your emitter/power supply circuitry overheats!

http://candlepowerforums.com/vb/showthread.php?t=119665&highlight=mag-led

This LED Zeppelin? http://www.candlepowerforums.com/vb/showthread.php?t=188683

Go visit the wonderful CandlepowerForums.com and look at this post in particular. http://www.candlepowerforums.com/vb/showthread.php?t=178130 7,000 L is not a big deal.

I suggest you spend some time reading though this forum:
http://www.candlepowerforums.com/vb/forumdisplay.php?f=45
or
http://www.light-reviews.com/

LEDs are no longer "rare" or just making entrances into flashlight or headlamp applications.

It is even possible to build your own flashlight or even a bulb for household current out of parts from this site:
http://www.dealextreme.com/products.dx/category.999

Just go here: http://candlepowerforums.com/vb/

Maybe not your car's generator but definitely being used by bikers on their bicycle generators for powering LED lights.

http://candlepowerforums.com/vb/showthread.php?t=172636

I see what you mean about the lumen being human tweaked. Can you have a quick read of my post here and tell me what you think:

http://www.candlepowerforums.com/vb/showthread.php?p=2415085#post2415085

I cannot understand what use this sort of light has for civilian usage.

A cursory Google search revealed this forum with that pic and some more interesting ones like what the flashlight looks like, the battery pack needed to power it, as well as some more illuminating photos (pun intended).

Ah, it's no Galvanick Lucipher.

There is help available, brother:

http://www.candlepowerforums.com/vb/

Leaving aside whether or not anyone 'needs' a brand name, other producers will appear even for high end luxury items and even when the market is not particularly large.

Part of my geekiness manifests itself in the form of flashlights. I like nice ones. 10 years ago if you wanted a nice flashlight you bought a Surefire, the only decent alternative was a Mag light which is not even close to Surefire quality or functionality. Surefire's dealers used to compete with one another and a visit to CPF would usually reveal one of them running a sale or whatever.

Dealer A complained loudly that Dealer B was underselling him. Dealers with no web presence complained about dealers with one. And on and on. (I know this because I work for Surefire sometimes). So to stop the complaining Surefire started a pricing policy that prevents any dealer from offering a flashlight below a minimum price, it also prevents any dealer from selling a light on the internet and shipping it directly to a customer, the light has to ship from Surefire's warehouse. This scheme works and the price of their flashlights has steadily risen, even on Ebay. Their policies were modeled after Oakley's (who I also work for sometimes).

Today one can buy any number of very nice flashlights from any number of companies. Arc is back in business. Fenix. And Jetbeam. There are even more guys making lights in their garages now than there were before the policy change. They all compete directly with Surefire, and the offerings from indirect competitors like Inova and Pelican have diversified. There are even companies competing in the weaponlight market, where as little as 5 years ago Surefire was really the only choice at any price point.

So in the flashlight market Surefire's pricing policies seem to have enabled their competitors. Indeed, if you want a big SF stamped on your flashlightyou still have to buy from them, but if you just want a nearly indestrucible metal bodied light that fits in your shirt pocket yet packs 60 lumens into its artifact free LED beam...you have a lot of choices.

I haven't personally tested these but they claim their NiMH batteries have a much lower self-discharge rate. http://www.rayovac.com/recharge/hybrid_technology. shtml http://www.candlepowerforums.com/vb/showthread.php ?t=138632

I'm in total agreement - it's a superb charger. and the refresh mode is brilliant - it constantly discharges and recharges the battery whilst measuring the output mah on the discharge and only stopped when the discharge capacity stops increasing (can take several days depending on the charge/discharge current chosen).

the charger is available over here in europe as the technoline icharger. it's exactly the same charger.

for a good battery comparison page, check this:
http://www.candlepowerforums.com/vb/showthread.php ?t=79302&page=1&pp=30
includes graphs, voltages and total power output for most commonly available rechargable AA battery types. the post appears to be dated 2005 but it's actually updated quote often with new battery stats added.

I'd second many people's comments. NiMH batteries are very very nice these days, and have far more capacity then they used to. http://thomasdistributing.com/ is good, and if you want cheap batteries, http://batteryspace.com/ is good, but their ratings are 400 mAh or so above their actual capacity. Sanyo or PowerEx is certainly good if you have the money, and 2500 mAh Energizers are a good locally available option. The real key is to get a good charger. I just got one of the new Maha MH-C9000 chargers (http://www.thomas-distributing.com/maha-mh-c9000- battery-charger.php) and it has the ability to do break-in charges, discharge, refreshing, etc. You can also just put batteries in it and it will charge them with a safe rate.

For applications like remotes, or other devices you want sitting around for a long time and ready to use, there are new NiMH batteries that have much lower self discharge rates. Eneloop batteries by Sanyo (http://www.eneloop.info/) have performed the best, and they can be picked up locally at Ritz camera locations as well as ordered online for a little less. They only lose a little of their charge over a years time. For more information about rechargable batteries, try the batteries forum over at candlepowerforums. (http://www.candlepowerforums.com/vb/forumdisplay. php?s=04cb1ed93243098d9b7795bae32555cb&f=9)

I see a lot of angst in this discussion without a lot of careful thought. (Hey, this IS /. after all... I shouldn't be surprised.)

The performance of these bulbs does vary ***greatly*** with the orientation of their installation.

As a personal example, I bought some CFLs for my parents' house and installed them base-up in overhead recessed fixtures. They were very understandably unhappy with the startup time - almost a minute of dim light in a kitchen is very unacceptable. But those same bulbs, base-down, were fine in other places in the same house. If I'd thought about it ahead of time, we could have purchased CFL "instant-on" bulbs and gotten much improved performance in the recessed cans.

CFLs use various types of gas mixtures, and some use drops of liquid mercury like other big fluorescents. If it's a liquid mercury bulb, it takes a short time to evaporate all the mercury when it's first powered on. In this situation, a base-down bulb will probably brighten faster than a base-up bulb, because the drop of mercury will initially be condensed near the emitter coils. The so-called "instant on" CFLs use a different, non-condensing gas mixture.

Also, the brightness profile may have some effect on bulb lifespan: instant-on bulbs may last a shorter time for various reasons. If you're willing to tolerate a slower warmup, you may pay less over the long run for bulb replacement.

See the discussion on this link, or google for "cfl base-up brightness":
http://www.candlepowerforums.com/vb/showthread.php ?t=104314

Moral of the story: there are reasons for these differences, and you can use those differences to your advantage, IF you're willing to think thru the data and specs a bit. Don't toss the baby out with the bathwater just because the "Duh, CFLs are good, heh heh heh" line isn't the whole answer.

Flashlight geeks have been dealing with this issue for a while.

http://www.candlepowerforums.com/vb/showthread.php ?t=78843

http://www.candlepowerforums.com/vb/showthread.php ?t=124776

There have been several documented "venting with flames" of primary CR123A batteries. Rechargeables seem to be a lot more stable, occasional Dell laptop conflagarations notwithstanding.

Flashlight geeks have been dealing with this issue for a while.

http://www.candlepowerforums.com/vb/showthread.php ?t=78843

http://www.candlepowerforums.com/vb/showthread.php ?t=124776

There have been several documented "venting with flames" of primary CR123A batteries. Rechargeables seem to be a lot more stable, occasional Dell laptop conflagarations notwithstanding.

LEDs are about to take over as the standard lighting in automobile headlights and flashlights. Their ruggedness and efficiency is pretty darn good compared to the alternatives. These quantum dots are a very interesting way of getting white light from blue or UV.

I've done the 5 watt LED conversion to a 2-D Maglight (also required converting to lithium batteries) as well as a simpler 1 watt drop-in bulb and reflector replacement for the 2-AA minimag. I think I will do the minimag conversion to another light or two. It is the best bang for the buck, and runs on commonly available AA cells, which cost about 20 cents each at CostCo for good alkalines. It retains the variable focus of the mini-maglite, a major plus. It is brighter, whiter, and the batteries work about 4x as long as they do with the original incandescent bulb.

LED-Replacement has a lot of drop-in replacements for various flashlight bulbs.

If you prefer to spend your money on a purpose-built LED flashlight, check out Amondotech for good deals on lights and batteries.

At Candlepower Forums you can find people who obsess over flashlights more than you or I do.

Flashlight Reviews is a great review site for various flashlights, including good definitions of the difference between lumens (overall output) and throw (how far away you can light stuff up.)

I'm just a flashaholic, and don't make any money from these companies.

Check out the video which is the first link on this page

Green laser burns a hole through a cup. But I admit that it could be staged.

More discussion here

see this site for some interesting flashlights. :-)

I retrofit flashlights with high-powered Luxeon LEDs. There is a fairly good-sized community of flashlight modders, and the work ranges from simple drop-in mods for cheap Minimags all the way to complete retrofits of $400 military-grade Surefire spec-ops flashlights, and some guys even fabricate entire flashlights in their garage.

Some examples:

McGizmo

Mr Bulk

candlepower forums

Sounds like you've spent too much time at CPF

When I used to work at a small start up company, we weren't full of those stereotypical portly nerds that drink mountain dew all day long and have a goofy laugh.

Instead, we had nice upstart individuals that were well motivated and very athletic. (if it's any consolation to you, they didn't take showers after working out)

Whenever there were any sorts of group events, we'd have at least two individuals with experience with hiking, backpacking, rock climb, scuba diving, spelunking, sky diving, flying jets or planes, rocketry, maguyvering stuff(a lot of them were engineers in mechanical, electrical, chemical, etcetera btw), and even inventing little items for personal use with fellow hobbyists.

Yes, I believe it is the insatiable quality of nerds that keep them above the rest in society. Always prepared for any event. If you stuck them on an island without electricity or any signs of human life, they'd be able to make a quaint existence on it until someone rescued them.

For examples of weirdness and whackiness for self made items. Check out this forum for flashlight enthusiasts.

A bunch of them make their own flashlights, or even offer modifications to Mag-Lites to make them into hand-held HID setups just like the UnderWater Kinetics Light Cannon 100 HID Dive Light

Yes, nerds are too overprepared.

For working around the house, pearing into dark corners, etc, I use an Opalec NewBeam drop in for my MiniMag. It is voltage regulated, so you get 10 hours of constant brightness, and it has a low a battery indicator LED. It is driven with 3 bright white LEDs. Nice, tight focused beam. Not quite as bright as the Maglight with the incadescent bulb and fresh batteries, but perfectly usable. And not too bright to annoying when using it to read in the dark, work up close to yuor face, etc.

For backpacking, I use a Black Diamond Moonlight headlamp, with 4 LEDs. Runs on 4AAAs, supposed to go for 70 hours, and is as bright as the NewBeam.

I like both very much. Probably THE best place for information like this on the web is Candle Power Forums, and the LED Museum. At CPF you'll find all sorts of user experiences with most everything out there, and some home grown "pill" style ultra bright MagLight dropins. These are guys who collet $100+ flashlights! And LED Museum has a ton of technical information and reviews.