Extremum - keychain flashlight with 400 lumen output

Hi. We've built a usual keychain flashlight with an unusual feature - it's output is 550 lumens. It has 3 level of brightness:And a strobe light. We want to ask your opinion - do you like the idea of powerful keychain flashlight with extra wide beam?p.s. Soon we'll add video with real world comparisons with other flashlights

Re: Extremum - keychain flashlight with 550 lumen output

Looks good. Whats the emitter and power source?

Re: Extremum - keychain flashlight with 550 lumen output

And how many seconds will it run at full power? Unless you have developed an extremely new power source, 500+ lumens would drain any cell that small in at most a few minutes.

Re: Extremum - keychain flashlight with 550 lumen output

It looks remarkable, but I would personally find more useful a light of that size with a maximum output of 200-250 lumens and a longer runtime on maximum output. Thanks for showing us the new light - very impressive!

Re: Extremum - keychain flashlight with 550 lumen output

The concept is not that unusual for anyone familiar with the MBI HF-R which has five levels of light, the fifth level outputting a similar amount of lumens (~550), the first level only 1 lumen .... and the HF-R runs on a 10180.

Obviously the high level is only for small bursts and is more to show-off than to use for any length of time.

The HF-R also has a nice classic reflector beam which results in a well-defined hotspot enabling decent throw in addition to good spill. Personally I prefer that beam shape to the one shown here.

Re: Extremum - keychain flashlight with 550 lumen output

Thinking the MatchBoxInstruments HF-R uses 10250, but who's counting, still impressive. Directions from MBI say to turn off or lower output in something like 20 seconds or less.

Good luck with your interesting project. Are there any time or temperature constraints with your light to keep the reckless and uninformed from destroying?

Re: Extremum - keychain flashlight with 550 lumen output

I had a similar one already, this one seems with a higher output, but how is the runtime and power source?

Re: Extremum - keychain flashlight with 550 lumen output

550 lumen is impressive. Would like to know how long the battery could last.

Re: Extremum - keychain flashlight with 550 lumen output

First of all a new update - we decided to squeeze only 400 lumens and limit current at 800 ma.
Some technical specs:
led: cree xml-l2 U3
driver: our own
battery: 10180

At max output you'll have ~4 minutes of 400 lumens and ~3 minutes of ~200 lumens.

Here is a link to our draft kickstarter project: https://www.kickstarter.com/projects/1727819497/1059833774?token=07e02905

and a few videos



We tried to achieve wide and almost uniform beam.

Re: Extremum - keychain flashlight with 550 lumen output

Why do you get only 3 minutes at 200 lumen and 4 minutes at the higher 400 lumens?

Re: Extremum - keychain flashlight with 550 lumen output

In response to your question: no, I'm not interested.

Power:
The beam is way too powerful for any keychain application I have ever needed.

Runtime:
Moreover, when I default to using my keychain light, I favor run time over massive output because it's an emergency light. Your current run times make it little more than a novelty.

UI:
You don't mention the UI, but it looks to be a twisty format, making it impractical for defensive scenarios or quick deployment needs.

Heat:
Anything that powerful is going to get hot, fast. Given the size, that will make handling it problematic for any use past a few seconds.

Batteries/power source:
Given the size, it's either a rechargeable or using a relatively obscure battery or batteries. Another factor for me in keychain lights is the ability to replace batteries with minimum fuss, if needed. Which is why I rarely - to date, never - deviate from using the AAA platform.

Beam profile:
There, I agree. I prefer a broader beam as being more practical in a keychain light.

Extremum - keychain flashlight with 550 lumen output

550 lumens is not unheard of, but it looks interesting. The wider beam makes sense, especially because it's a keychain light. Normally you use a keychain light in say, the car, so +1 on the beam.

I don't mind the unconventional battery size. In fact, this size and chemistry is most pragmatic considering how fast a light of this size and output will go through batteries. The 10180 is great for keychain use, as opposed to other popular formats like AAA (heavier, longer, and less voltage).

Twisty format also makes sense, so as to conserve space. I will say, however, that this is relatively common and falls quite short of the MBI HF's intuitive tailcap twisty.

200 to 400 lumens doesn't make a lot of sense, because both blow through the battery so fast with little perceivable change in output. From what I can see, the 200 lasts less time even, so all the more reason to scrap it.

In conclusion:

Very interesting light overall, and I will definitely be interested to follow its progress. With that being said, it is up against stiff competition from the MBI-HF that pre-dates it by several years and is still more advanced. The MBI HF is brighter, has an ingenious mode switching mechanism, and a carry case that stores extra batteries and syncs with the HF as a larger light. The HF is, without a doubt, at the apogee of keychain light innovation and design (although George's new 10280 light he's working on with the programmable driver does look pretty damn cool). More innovations would definitely benefit this light.

Re: Extremum - keychain flashlight with 550 lumen output

It gets 8 minutes on turbo which is ~4 minutes @ 400 lumens then ~3 minutes @ 200 lumens. That is just turbo mode. It has 3 modes. 20 lumens, 120 lumens, and 400 lumens.

I agree that the MBI HF is better, but this is also less than half the price. There is a place for both.

Is the MBI HF currently available? I thought everything from MBI to as currently on hold.

Re: Extremum - keychain flashlight with 550 lumen output

I love powerful little keychain sized lights like this! I do use the highest levels on my MBI here and there -- at 500ish lumens, it can be used for most anything that isn't long-distance. So this sounds great to me.

My one concern might be the switch. The MBI's switch was a twistie at the back, and I am not the only person who had trouble with it turning on in my pocket, multiple times. I then put it on a dangler, and it still turned on by itself. I contacted MBI and they sent me a new switch that was tighter and has never turned itself on, but even so I guess I just plain don't love the switch, don't love not being able to tell, when I twisted the switch off, how close it was to the next mode, and hence might turn itself on. I far, far, far prefer the switches on the cheap Mecarmy type 10180s, and in fact those little 120 lumen lights almost always knock the MBI out of my pocket, because they're so much more natural and easy to use than that real twisty on the MBI. I'm guessing from the pics, your switch is that little nub on the back? The light might be a no-brainer for me if not for that switch; now I'd need to think about it a bit. I realize you don't have many options if you want 3 modes and compactness, and don't want to do a lowest-common-denominator head-twist switch

Re: Extremum - keychain flashlight with 550 lumen output

Need to fix the thread title. It overstates the actual output by 37.5%.

edit: I see this has now been corrected.

Thanks!

:thumbsup:

Thanks for your response!
We'll try to answer all questions:

1. We decided to lower output to 400 lumens. Unlike mbi you can use our light until you drain battery, not only for 15 sec as 'more advanced' mbi hf. We use copper thermal pads for cree xml-l2 u3 and managed a problem with overheating.
2. Mode selector is a button at the end of flashlight. We don't like rotating heads on keychain flashlight.
3. We've created our own driver for that flashlight. To avoid accidental switches modes are changed through double click. Off -> double click -> low -> double click -> med -> double click -> Turbo -> double click -> strobe
But we would like to hear your opinions about the way of switching between different modes. We can program our driver in any way.
4. Heat - extremum will be still comfortable to handle after 5 minutes of turbo mode. Why? Cases are made either from steel or titanium. Both metals haw low thermal conductivity (especially Ti version). Only lens would be rather hot. Bun not to the level to injure somebody.

Here are actual beamshots on 400 lumens. Iphone 7, Iso 500, 1\10 sec:





p.s. Tomorrow we'll start kickstarter campaign and if you're interested please support our project and\or tell about us to your friends. We've already made one successful project https://www.kickstarter.com/projects/1727819497/cardlight-powerfull-flashlight-in-a-size-of-credit and have only positive feedbacks. Sure, we're not a flashlights guru but we're quickly learning and always trying to keep our promises. No fake lumens, no fake beamshots or lying about runtime.

ProjectOne said:

Thanks for your response!
We'll try to answer all questions:

1. We decided to lower output to 400 lumens. Unlike mbi you can use our light until you drain battery, not only for 15 sec as 'more advanced' mbi hf. We use copper thermal pads for cree xml-l2 u3 and managed a problem with overheating.
2. Mode selector is a button at the end of flashlight. We don't like rotating heads on keychain flashlight.
3. We've created our own driver for that flashlight. To avoid accidental switches modes are changed through double click. Off -> double click -> low -> double click -> med -> double click -> Turbo -> double click -> strobe
But we would like to hear your opinions about the way of switching between different modes. We can program our driver in any way.
4. Heat - extremum will be still comfortable to handle after 5 minutes of turbo mode. Why? Cases are made either from steel or titanium. Both metals haw low thermal conductivity (especially Ti version). Only lens would be rather hot. Bun not to the level to injure somebody.

p.s. Tomorrow we'll start kickstarter campaign and if you're interested please support our project and\or tell about us to your friends. We've already made one successful project https://www.kickstarter.com/projects/1727819497/cardlight-powerfull-flashlight-in-a-size-of-credit and have only positive feedbacks. Sure, we're not a flashlights guru but we're quickly learning and always trying to keep our promises. No fake lumens, no fake beamshots or lying about runtime.

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I would prefer a much lower low. It doesn't have to be moonlight but maybe 5 or 10 lumens as the low. My preference would be that strobe would not be included or that it would be hidden.

As far as your previous project, it looks like there are still backers that have not received their items. Is there a reason for this and will the all be taken care of?

moshow9 said:

I would prefer a much lower low. It doesn't have to be moonlight but maybe 5 or 10 lumens as the low. My preference would be that strobe would not be included or that if would be hidden.

As far as your previous project, it looks like there are still backers that have not received their items. Is there a reason for this and will the all be taken care of?

Click to expand...

All modes would be discussed several times with all backers. With polls etc.

To all backers that haven't received their pledges we've re-sent their flashlights with tracking. It's our responsibility that everyone should receive what was promised.
Unfortunately we choose bad postal company and about 5% of all parcels were lost ;( We study on our mistakes and now we'll ship only with tracking codes and by another (more pricy) postal company.

ProjectOne said:

.... Heat - extremum will be still comfortable to handle after 5 minutes of turbo mode. Why? Cases are made either from steel or titanium. Both metals haw low thermal conductivity (especially Ti version) ....

Click to expand...

If you are not conducting all that heat away from the emitter and electronics, then where is it all going ...

archimedes said:

If you are not conducting all that heat away from the emitter and electronics, then where is it all going ...

Click to expand...

Through the end with lens. Also xml-l2 u3 is very effective and when you drive it with 800 ma you don't need that much heat dissipation as you needed on previous generation of leds.