# Skilhunt H03 Headlamp Mods for Waist Light



## ThinAirDesigns (Dec 15, 2016)

Hi there. New contributor, but have read the these forums for some time and made great use of the knowledge herein. Thanks to everyone who contributes.

This post is only going to be partially headlamp related so bear with me. I've decided to post it here since it involves mods to headlamps and there's no specific forum for waist mounted lights.

I am a recreational ultra-marathon trail and mountain runner. This regularly involves training and competing on rugged mountain trails at night (I often run close to 80 miles a week -- with a significant chunk of this at night).

I have a strong climbing and backpacking background and have used Petzl and Black Diamond headlamps for decades now -- with reasonable success and happiness. For running however I need more light to read the terrain quickly (especially as I've aged), so I've added a handheld LED flashlight. This brings up the shadows, compensating for the flat nature of headlamp lights. I usually run with something like a Petzl MYO (370lm) and a 2-300lm handheld.

A handheld works great most of the time, but during longer races / runs, I really need my hands for hydration and nutrition -- something you can't skimp on and hope to finish 100 mile distances. Also, I can smash handhelds up pretty good when I trip and fall on rocks - you throw your hands out to break a fall and guess what gets slapped on the rocks very hard. I've thought about strapping something like a Zebra to the back of my hand (leaving my hands sort of free for eating and drinking), but the light blinds me when I drink and I have a fear of breaking bones in my hand if I go down as on the back of the hand they are not well protected.

Recently I got thinking about waist mounted options and I looked at the UltraSpire Lumen 600. I liked the concept (they show up on competitors at ultra-marathon races regularly and are well liked) and would have bought one but I know just enough about flashlights to recognize how crappy the light itself actually is (the belt is great). For the price ($175) I can do a ton better light wise. Their claims for the light are nonsense (some reviewers claim 8+ hours on high) as I know from watching them used that they are unregulated. Yes ... it will burn a long damn time on "high", but not with 600 lumens. I know the limitations of the 18650 battery so I'm not fooled.

I don't know if UltraSpire had someone design a light specifically for them or just slapped their name on some already existing Chinese OEM product (someone here might recognize the light ... who knows). It looks like they even just sewed the somewhat standard silicone / rubber ring mount into their belt. Following are a couple pictures of the product for those not familiar with it.














What I'm going to get into next will make more sense if I describe my background -- I've worked for many years as a mechanical engineer and designer in the Silicon Valley. While mechanical is my specialty, I'm reasonably familiar with the electronic (and programming) side as well. In my work I was responsible for integrating such into my mechanical designs. I am also a competent machinist with access to extensive shop including CNC.

I also love projects that result in unique and hopefully usable doodads, so if someone asks "why are you doing this instead of just buying 'product X' which is sort of like this?", the answer may just be "Because I like building things I consider to be cool". Just call me a nerd.

So here are my 'wants' for what I consider the ultimate in a waist mounted ultra-marathon light:

1: External battery
Not only is there no need for an internal battery (the light is belt mounted after all), but a battery in the light adds bouncing mass to the very item you wish to be the most stable. It also limits the capacity. An external pack allows for the weight to be better controlled, and provides battery sizing options depending on the length of the run / race. Full nights of unsupported racing requires 8-12 hours of light. A short training run? -- well, you get the idea. Pick your battery pack.

2: Low profile (minimal 'overhang'). 
This one is easy to understand -- the more overhang, the more bouncing.

3: The ability to run both 'spot' and 'flood' at the same time with independent aiming.
I want flood at my feet (and specifically the 20 - 30 ft in front of me) for working the terrain while also having a bright spot aimed down the trail for route finding. Currently I use the handheld for the localized flood and aim my headlamp a bit higher than I would normally with a headlamp alone. This allows me to just move my eyes up for those split second views into the spotlighted further distance and then back down to the well flooded local terrain. 

4: Lumen settings in the 200 - 500 range on each light (adjustable independently).
Rain and fog actually make higher outputs counter productive - heavy underbrush the same as there's too much reflecting going on. Heavily wooded trails favor medium outputs, while open desert terrain with nothing to reflect just eats up light and requires higher settings. Snow of course kills the the eyes of lit too bright.

5: Redundancy.
While I don't mind sharing a common power source (it's redundant in that I would carry a spare battery), I would like my waist light to have two independent sets of circuits, switches and LEDs for obvious reasons -- people train for months, fly halfway round the world and then sit beside the trail until the sun comes up because of light issues. Redundancy rules.

With that in mind, here is what I'm thinking of doing and this is where the knowledge base from this forum comes in: Following are a series of screen grabs from my CAD program. My written details will make more sense if I just show the pictures first so here goes:






















OK -- in short what I'm proposing is to take two right angle, tube style headlamps (Zebra, Armytek, etc), remove the battery compartments and mate them up to one central (and shortened) tube and then powering them externally. This assembly then mounts right up to a belt like the UltraSpire shown above with the battery(s) going in one of the pockets.

As many here have already recognized, I modeled the Spark SG6 but I'm not at all insisting (or sold) on the SG6 as the desired unit. I used the SG6 merely because the 'flood' and 'spot' lenses were visually distinguishable which made it easy to display what I was trying to accomplish. I also set the two heads at what is likely an exaggerated offset angle -- also just to make it obvious that I want the lenses to be able to aim independently.

The combined unit would be as light (or perhaps even a touch lighter) than a single unit with installed 18650 battery.

While anything is possible, using a model which has a head machined separately from the battery tube might make things easier (assuming they can be separated). The Zebra line appears to be one piece, while I've seen pics on this forum of the SkilHunt tube unscrewed from the head so those two models sort of bracket the options.

As far as the battery pack(s) go, I'm not sure if an empty case something like pictured below, refreshed by dropping in new singles would be the best route, or perhaps a bicycle battery pack (second pic below) or even make up my own packs. Perhaps some combo of the above -- the singles case for shorter training runs and a bigger packs for all-nighters. These would be questions I would also like input on.













So for all the experts on board -- what are the pitfalls that you see? Remember, neither cost nor effort is the driver here (though I think I'll still be in the price range of the Ultraspire 600 and with a FAR better package). 


Thanks.

JB


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## tech25 (Dec 16, 2016)

*Re: Headlamp Mods for Waist Light*

Welcome to the forum! This looks really well thought out and learning from experience, good luck with this project! 

I am no expert but am interested in seeing you go through with a perfect working model for your needs. 

My two questions that I have: when you're running are you going to be able to change levels on the fly easily with the buttons like that ( will the jarring of the running throw off your hand from the button) ? And also I see you fixed the position of the two beams are there any times that you need to change those positions of the flood or spot?


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## Szemhazai (Dec 16, 2016)

*Re: Headlamp Mods for Waist Light*

I've done this a few years ago - copper case home made on a gas stove - one led is pointed a few degrees downwards. It is still used for a friend of mine in Nordic Walking trainings. The main issue is that the cable is breaking quite often - to much movement here.


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## lampeDépêche (Dec 16, 2016)

*Re: Headlamp Mods for Waist Light*

Nice stuff, ThinAirDesigns!

Just a small tip--the Acebeam H20 also has the feature that its head threads off from the battery tube, so you might be able to use this for a two-headed push-me-pull-you.

http://www.acebeam.com/headlight-h20-cree-xp-l-hi

Szemhazai--
I like your design, too, and the materials that you used bring to mind the famous "plombier Polonais"!


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## ThinAirDesigns (Dec 16, 2016)

*Re: Headlamp Mods for Waist Light*

Szemhazai -- nice work. I figured it was too obvious of a configuration to not have been thought of before. There are good strain relief grommets available now for the wire so I think that problem can be overcome.

Thanks for the pics.

JB


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## ThinAirDesigns (Dec 16, 2016)

*Re: Headlamp Mods for Waist Light*



tech25 said:


> Welcome to the forum! This looks really well thought out and learning from experience, good luck with this project!
> 
> I am no expert but am interested in seeing you go through with a perfect working model for your needs.
> 
> My two questions that I have: when you're running are you going to be able to change levels on the fly easily with the buttons like that ( will the jarring of the running throw off your hand from the button) ? And also I see you fixed the position of the two beams are there any times that you need to change those positions of the flood or spot?



Thanks for the kind words tech25.

I don't believe there will be any need in my application to be fiddling with the buttons while on the move. I'm pretty sure I can just select the appropriate level for the conditions and then it will likely stay that way for hours.

As far as beam adjustment goes, I suspect that once I find the best offset angle between the two, it will remain that way forever. I will make that offset adjustable, but it will be super duper stiff so that they don't wander around relative to each other. Of course the entire assembly will still rotate in the rubber rings to allow for angle adjustment - just like with my headlamp, I will want to tilt it down for long steep descents and up for long climbs.

JB


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## ThinAirDesigns (Dec 16, 2016)

*Re: Headlamp Mods for Waist Light*



lampeDépêche said:


> Nice stuff, ThinAirDesigns!
> 
> Just a small tip--the Acebeam H20 also has the feature that its head threads off from the battery tube, so you might be able to use this for a two-headed push-me-pull-you.



Thanks for that tip. Had not seen that option.

JB


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## tech25 (Dec 16, 2016)

*Re: Headlamp Mods for Waist Light*



ThinAirDesigns said:


> Thanks for the kind words tech25.
> 
> I don't believe there will be any need in my application to be fiddling with the buttons while on the move. I'm pretty sure I can just select the appropriate level for the conditions and then it will likely stay that way for hours.
> 
> JB



I was just thinking if it's foggy out and then clears or going from a narrow trail to wide open, an easier way to change modes might be helpful. Or maybe with those buttons- just a few necessary modes with a press and hold the buttons as it scrolls through the modes and release to stop when you want it- (much like the zebralight ui)


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## RLDubbya (Dec 17, 2016)

*Re: Headlamp Mods for Waist Light*

Take a look at Gemini headlamps, I think there might be some knowledge to be gained. They have been designing and bringing headlamps to market for quite a number of years. They are currently using an 18650-based solution; they offer separate battery packs. Looks like their current top-end offering is a 8-cell pack, driving a 4,000 lumen 6 LED light unit that gets 2 hours 40 min of runtime. FWIW, I like their beam profile and color tint.

The battery packs are separate from the head units, and they also offer extension cables - so you can get any length you want. The head units mount via a separate piece of hardware to bikes, helmets, and headbands; so the bracket bolts on, then the light clicks into place on the bracket.

I wonder if you could purchase a running belt, get a seamstress to mount the bracket, and be good to go.

I do have one question: What about a green LED? Would that have any compelling advantage? Since it preserves night vision, would it help to reduce the tunnel vision that comes from wearing a headlamp? I've talked with several ultra-runners (my wife is into trail running as well, but has yet to do her first ultra), and they talk about getting fairly several nausea induced by the tunnel vision from the headlamp. Would a waistlamp by itself eliminate tunnel vision?

The green is also said to not attract bugs.

One company, TekTite, makes a CSI series of handhelds that include green leds they claim are good for night running. 

I don't know if the above will help, I'm really just kind of babbling out loud. Got to vent the little voices every now and then to minimize the back pressure...


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## ThinAirDesigns (Dec 17, 2016)

*Re: Headlamp Mods for Waist Light*



tech25 said:


> I was just thinking if it's foggy out and then clears or going from a narrow trail to wide open, an easier way to change modes might be helpful. Or maybe with those buttons- just a few necessary modes with a press and hold the buttons as it scrolls through the modes and release to stop when you want it- (much like the zebralight ui)



Usually I find that conditions don't change often or quick enough for me to need to do much setting changes on the fly. I ran in a 50 mile race today and it was foggy almost the entire day for instance (top of a mountain and in the low clouds). The last hours in the dark there was simply no use at all for a headlamp and I just took mine off and held it low in my hands. I HATE headlamps in the fog and was really wishing for a good waist-belt solution all evening.


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## ThinAirDesigns (Dec 17, 2016)

*Re: Headlamp Mods for Waist Light*



RLDubbya said:


> Take a look at Gemini headlamps, ...



I have looked at a couple different models of those. I have mountain bike friends that use them and did consider them (and am still considering their battery packs). The issue I have with them is I have not seen a great 'flood' version. MB lights tend more towards the 'throwy' end of the scale as they need light out front rather than at their feet. Also, the beams aren't independently aimable that I can see. That small single is a nice light package if they only had a flood option.



> What about a green LED?



Not sure -- never tried them. Have had many headlamps with red LEDs and never really took to them. Have had no problem with tunnel vision while night trail running. Might be fun to try green just to see, but so far I've had no issues with just lighting the trail up and getting on with it.

Thanks for the suggestions. 

JB


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## RLDubbya (Dec 18, 2016)

*Re: Headlamp Mods for Waist Light*

In talking with my ultra buddies, the problematic vision issues hit at like hour 12; one guy told me he regularly pukes from it. I see that makers of waist lamps claim tunnel vision is eliminated by just using the waist location instead of the head.

Green light is popular with hunters. It definitely preserves night vision, and it also seems to preserve detail, etc. that red washes away.

I have not used the newer Gemini lamps, but: they made a somewhat floody light called the Titan a few years ago. The head was on the small (for them at the time) side, and provided something like 900 lumens. I was wondering if you could mount two of these, which would give you redundancy and some independent adjustment.

Another thought: could Gemini handle the manufacturing on a contract basis, working to your specs? They strike me as being a fairly small, hungry company.

Best of luck with your project. My wife wants a chest band version, fwiw. She feels the waist version doesn't quite work. If you get prototypes built and need testers, she would be keen to help you, to see if your concept of a waist version works for her needs.


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## ThinAirDesigns (Dec 18, 2016)

*Re: Headlamp Mods for Waist Light*



RLDubbya said:


> In talking with my ultra buddies, the problematic vision issues hit at like hour 12; one guy told me he regularly pukes from it. I see that makers of waist lamps claim tunnel vision is eliminated by just using the waist location instead of the head.



No idea ... never suffered from it and don't know anyone that has.



> Green light is popular with hunters. It definitely preserves night vision, and it also seems to preserve detail, etc. that red washes away.



As far as I know, Ultrarunners have no reason to preserve night vision. We want things lit as bright as practical and we want it to stay that way till we see the sun or the finish line. 



> I have not used the newer Gemini lamps, but: they made a somewhat floody light called the Titan a few years ago.



With a search of back models from Gemini, I did find the Titan to which you refer, but no reviews that I read comment on it's 'throw' or 'flood' nature. Even if it were floody, it's tech is from close to a decade ago so I can't imagine it's efficiency is going to be up to current par. Additionally, it's much too big by comparison.







The form factor is also the problem I have with the current line from Gemini. The more cantilever the more bounce and the belly isn't exactly the most stable or locations to begin with. Below you can see the Gemini Duo and it looks to require something like twice the cantilever as a design made from a Zebra style light.








> Another thought: could Gemini handle the manufacturing on a contract basis, working to your specs? They strike me as being a fairly small, hungry company.



I have no idea what interest Gemini would have in building one single light to my specs, but I'd be surprised if the costs weren't far out of line compared to what someone like myself can do. Besides ... as I stated in my OP. I LIKE building things for myself, and have the equipment and experience so I'm not going to skip that step. 



> Best of luck with your project. My wife wants a chest band version, fwiw. She feels the waist version doesn't quite work.



She might be right that the chest is better -- I'm still trying to decide that for myself. I do know that in the fog, the lower the better, but other than that I'm not yet sure. If the base light is good, the mounting options can be worked out.




> If you get prototypes built and need testers, she would be keen to help you, to see if your concept of a waist version works for her needs.



Thanks - this isn't something for market. This is just a one off for me.

JB


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## ThinAirDesigns (Dec 19, 2016)

*Re: Headlamp Mods for Waist Light*

Well, it looks like I won't be using the Spark SG6 (my first choice) for this project. It's looking more and more like Spark is not a reliably viable entity anymore (looking for feedback on this if I'm wrong). The latest "news" on their website is from 2012 and even finding someone who carries their products leads to limited results.

I liked the fact that their button was on the end (which would make the controls symmetrical on the mirrored units) and the ability to change out the lens from spot to flood was an appealing flexibility. Oh well.

So now the leading candidate is the Skilhunt H03. Like the SG6, it also has the head machined separate from the battery tube (making it removable). It also has a wide range of input voltage possibilities (accommodating many battery pack options). I'm worried that with the side button it will be hard to adjust the light in the holder (with gloves and the like) without hitting the button but we'll see.

JB


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## Trango (Dec 19, 2016)

*Re: Headlamp Mods for Waist Light*



ThinAirDesigns said:


> Well, it looks like I won't be using the Spark SG6 (my first choice) for this project. It's looking more and more like Spark is not a reliably viable entity anymore (looking for feedback on this if I'm wrong). The latest "news" on their website is from 2012 and even finding someone who carries their products leads to limited results.
> 
> I liked the fact that their button was on the end (which would make the controls symmetrical on the mirrored units) and the ability to change out the lens from spot to flood was an appealing flexibility. Oh well.
> 
> ...



Hi, take a look at the Imalent HR20, it also has a separate head (at least according to images, don't own one), has an infinitely variable rotatory switch in the end (don't know how practical is it with gloves) and accepts 18650 and 2xcr123.
It has a xpl-hi emitter and a claimed beam distance of 225m (on max), which can be good for the throw part of your belt.

Good luck with your project!


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## ThinAirDesigns (Dec 19, 2016)

*Re: Headlamp Mods for Waist Light*



Trango said:


> Hi, take a look at the Imalent HR20, ...
> 
> Good luck with your project!



Thanks Trango. Had not seen that option so it was good to know about it. Has some interesting features. The one thing that drops it out of consideration is that from all I can find there are not two versions (spot and flood) and I specifically need one of both in the assembly.

Thanks again. Always good to look around.

JB


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## lampeDépêche (Dec 19, 2016)

*Re: Headlamp Mods for Waist Light*

I don't own a Skilhunt, but I see that its lens is held in by a faceplate with 4 Torx screws.

You might see if that will allow you to remove the reflector, and use one of the two heads as a pure mule (no reflector, no lens, no optics of any kind).

Mules have a lot of advantages for running, because the light is so even and diffuse. Plus, there is no transmission loss.

Might not work, if the reflector won't come out, or if the beam is just too weak (mules don't throw). But might be worth the trial.


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## ThinAirDesigns (Dec 19, 2016)

*Re: Headlamp Mods for Waist Light*



lampeDépêche said:


> I don't own a Skilhunt, but I see that its lens is held in by a faceplate with 4 Torx screws.
> 
> You might see if that will allow you to remove the reflector, and use one of the two heads as a pure mule (no reflector, no lens, no optics of any kind).
> 
> ...



Great idea. According to the review here on this forum, it should pop right out. I'll try that.


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## lampeDépêche (Dec 19, 2016)

*Re: Headlamp Mods for Waist Light*

Yeah, personally I dislike those pebbly diffusers. They throw a bit, but nowhere near enough for seeing at a distance. And they are not purely floody like mule.

My wife runs in the dark some mornings (here in the north it is very dark at 6a). I loaned her my pure mule ZL 603d, and she said that everyone in her running group raved about how "it didn't bounce", i.e. there was no hot-spot bobbing around. Pure mules give the impression that the source isn't moving, even when it's bouncing up and down on your head! Everyone just sees even light.


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## ThinAirDesigns (Dec 19, 2016)

*Re: Headlamp Mods for Waist Light*



lampeDépêche said:


> ... everyone in her running group raved about how "it didn't bounce".



That's really interesting because just this evening (while taking our trash down a long rural driveway to the road) I was playing with a new relatively cheap LED flashlight I picked up to play with (a Nebo Cryket). It has an extremely broad and diffused flood setting and with it turned to a right angle and clipped to my belt (it's one of those twisty top lights that can adjust any angle) I couldn't notice it bouncing, but when on spot it just annoyed the poop out of me.

I realized that perhaps I'm wrong about wanting one flood and one spot on my assembly. I think the spot aimed out long might just be a total visual pain in the ***.

I really wish the Spark SG6 was a viable option because then I could throw in the reflector and if I didn't like it, just put the flood lens back in. Now I'm trying to decide if I order a Skilhunt spot and a flood or just two floods. I'm really afraid my spot idea may well be bunk.

Decisions.
JB


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## lampeDépêche (Dec 19, 2016)

*Re: Headlamp Mods for Waist Light*

Well, you'll just have to try lots of different experiments--there's no other way to gain the info you need. 

(Not even by asking random over-opinionated strangers on the Internet!)

My guess is that you are used to holding the long-range spot in your hand, and that overcomes a lot of the irritation factor. Your hand acts a bit like a steady-cam to dampen the bouncing, and you also have more control over where it points. (Control has a big effect on perceived motion--it's a lot harder to get car-sick when you are in the driver's seat, because you are in control of the twists and turns and get rigid feedback through the steering wheel.)

So maybe keep the flood on your belt, with a hand-held spot in a convenient pouch or holster? A pouch that makes it easy to stow it for two-handed eating, drinking, or map-reading, and then pull out the light for looking down the trail when needed? 

That Nebo is kind of amazing for $25. I've never seen one before, and, sure, it's a crap light. But that much functionality for that little cost, it's just incredible. I should get one for the car.


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## ThinAirDesigns (Dec 19, 2016)

*Re: Headlamp Mods for Waist Light*



lampeDépêche said:


> My guess is that you are used to holding the long-range spot in your hand, and that overcomes a lot of the irritation factor.




You are exactly right. This was why I was surprised how much (HUGE) the bounce was on the spot setting when clipped to my belt. In my hand it was not a big deal even when running. The flood on the other hand looked totally solid.




> So maybe keep the flood on your belt, with a hand-held spot in a convenient pouch or holster? A pouch that makes it easy to stow it for two-handed eating, drinking, or map-reading, and then pull out the light for looking down the trail when needed?




You may have suggested the best option there. I'm also wondering about the Skilhunt H02f version which has the spot reflector and the flip down diffuser. It would remain closed about 99% of the time, and just flipped down if I need to stand still and do some distant spotting and then immediately closed again. There is a review for that light here on the forum and the durability of the pivot system for that diffuser was seriously brought into question however.




> That Nebo is kind of amazing for $25. I've never seen one before, and, sure, it's a crap light. But that much functionality for that little cost, it's just incredible. I should get one for the car.




I was actually quite impressed with it's quality for the $21 bucks I paid for it (including shipping). The pivot mechanism is clean and crisp (with detents). The switch has good feel and overall I'm quite pleased (though I'm no flashlight snob). I'll probably order a couple more to throw in my other vehicles as you say. Wish it didn't have the red -- a total waste (super, SUPER dim).


Thanks.


JB


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## ThinAirDesigns (Dec 20, 2016)

*Re: Headlamp Mods for Waist Light*

Ordered up two NW H03 Skilhunts and a Nitecore D4.


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## Trango (Dec 20, 2016)

*Re: Headlamp Mods for Waist Light*



ThinAirDesigns said:


> Ordered up two NW H03 Skilhunts and a Nitecore D4.



Be sure to check the charger when you get it, there seem to be a lot of Nitecore fakes around.


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## ThinAirDesigns (Dec 20, 2016)

*Re: Headlamp Mods for Waist Light*

It's a thread derail, but since it's my thread and I'll be waiting for my Skilhunts for a few days I figured I would show lampeDépêche what I did today with the Nebo Cryket.

First, here's where my Cryket adventure started: This is a Nathan Zephyr running light. It's one of the runners answers to the problem of flat headlamp lighting. Besides it getting super bad reviews as a crappy light quality wise, many people (including me) noticed that the head wasn't angled down enough to be able to keep the hand in a comfortable position while running. We were like "If you're gonna angle it specifically for running ... angle it *enough*."








Thus my quest began for a light with the correct angle. This lead to swiveling head options because hey ... I don't know what the correct angle is and it might well vary from runner to runner. Models such as the Fenix MC11, the Rofis Tr20, Klarus AR10 and of course the Cryket were considered. I started with the Cryket simply because it was cheap and I wanted to see how comfortable it was to run with a correctly angled hand torch. Turns out from the playing around in the driveway last night, that what looks like the correct angle for both of us is something like 70 degrees or so.

So tonight my GF and I go on a group night trail run so we get to test it out. We sewed up an adjustable stretchy velcro hand strap with a couple tabs that the clip slips down through (the clip on the Cryket fits very solid). The idea here is that (like the Nathan running light above), if you lose your balance or something and wave your arms around, you won't lose the light.

GF will run with this and a Black Diamond Storm (170 lumen version). We'll see how it works.


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## ThinAirDesigns (Dec 20, 2016)

*Re: Headlamp Mods for Waist Light*



Trango said:


> Be sure to check the charger when you get it, there seem to be a lot of Nitecore fakes around.



Hmmm. That worries me, since I couldn't tell a Nitecore from a Daycore (I'm probably their dream customer then. LOL)

JB


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## lampeDépêche (Dec 20, 2016)

*Re: Headlamp Mods for Waist Light*



ThinAirDesigns said:


> It's a thread derail, but since it's my thread and I'll be waiting for my Skilhunts for a few days I figured I would show lampeDépêche what I did today with the Nebo Cryket.
> 
> 
> Thus my quest began for a light with the correct angle. This lead to swiveling head options because hey ... I don't know what the correct angle is and it might well vary from runner to runner. Models such as the Fenix MC11, the Rofis Tr20, Klarus AR10 and of course the Cryket were considered. I started with the Cryket simply because it was cheap and I wanted to see how comfortable it was to run with a correctly angled hand torch. Turns out from the playing around in the driveway last night, that what looks like the correct angle for both of us is something like 70 degrees or so.
> ...



Very cool! I am so glad that you are experimenting with this stuff. That's how the community learns.


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## ThinAirDesigns (Dec 21, 2016)

*Re: Headlamp Mods for Waist Light*

The Nebo Cryket adventure just got interesting enough that I'm going to start another thread for it over in LED Flashlights (spoiler ... it started cutting off with seemingly heat related issues last night during it's first use).

JB


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## WigglyTheGreat (Dec 22, 2016)

*Re: Headlamp Mods for Waist Light*

I have some experience with waist mounted and chest mounted lights as well as headlamps. I've tried different combos of beam patterns on the waist, but my favorite is a Zebralight H602w on the waist which is a mule type light. I tried the H600w on the waist with and without diffuser on it , but I went back to the H602w for the waist. There's no bouncing effect with a mule type light. I also use my H600w which I use diffuser over on the head and then carry a throwy handheld single 18650 light. So I have a mule waist level, throwy handheld, and also a floody (not mule) headlamp. I like this setup best. I take the top band off my Zebralight and just put the light around my waist using the zebralight strap. Works great for me.

I have also used chest mounted lights using a gopro chest mount. I used to use a Gloworm X2 light mounted to the chest strap and hook it to a 4 cell 18650 pack. That worked well, but I didn't need the longer runtimes and so the Zebralights are more convenient for me and I prefer waist mount. The Gloworm X2 allow for changing optics so you could have 1 flood and one with more throw. In the US Gloworm X2s are available from actionled and offer gopro mount options. I believe Lupine lights and probably a few others can mount to a gopro chest mount too.


----------



## ThinAirDesigns (Dec 22, 2016)

*Re: Headlamp Mods for Waist Light*



WigglyTheGreat said:


> I have some experience with waist mounted and chest mounted lights as well as headlamps.



That's great info Wiggly -- thanks.

I'm really wishing the Spark SG6 weren't gone (going?) as it looked like it was a 'mule' style (not sure ... all new to me). I'm hoping that I can mod at least one of the H03s that I've ordered to replace the TIR lens with something clear and still retain weather resistance - it sure makes sense if one wants to avoid the visual 'bounce' that you and lampeDépêche have talked about. We'll see. Too bad the case design of the Zebra just doesn't lend itself to my structural mods as well as the Spark or Skilhunt do.

Is there some particular reason you prefer waist over chest mount? Is it more stable or out of the way or better shadows on the trail?

Thanks again. Appreciate the input from everyone.

JB


----------



## ThinAirDesigns (Dec 22, 2016)

*Re: Headlamp Mods for Waist Light*

And another quick update for lampeDépêche on the Cryket. 

I tried to get the issue to repeat here at the house so I could write up the issue in a new thread and quickly discovered it wasn't a heat problem as I suspected from it's behavior after that one run. Couldn't get the damn thing to misbehave even with a heat gun cooking the crap out of it.

Soon because to realize it was a *cold* problem (alkaline batteries). It was in the 30s(f) on the run and after an hour and a half it finally got cold soaked and the batteries dropped off. Same batteries ran fine here in the house for another hour or so. New set worked fine as well. I tried a new set because I was still thinking a heat issue and I thought the used set might not kick enough to get it hot, but the new set wouldn't either (that's when I started thinking "cold").

In the end (using the freezer), I realized what the issue was. The Cryket is fine (though it seems a bit sensitive to low voltage if you ask me). When my new charger arrives we'll pop in some lithium rechargeables and see how it behaves in the cold.

JB


----------



## lampeDépêche (Dec 22, 2016)

*Re: Headlamp Mods for Waist Light*

Got it--you must have been out in some cold weather, if a handheld light still had the alkalines freezing!

The good news here is that if I *did* buy one as a glove-box light, I would definitely fit it with Lithium primaries--no leaks and longer shelf-life, as well as better temperature range.


----------



## ThinAirDesigns (Dec 22, 2016)

*Re: Headlamp Mods for Waist Light*



lampeDépêche said:


> Got it--you must have been out in some cold weather, if a handheld light still had the alkalines freezing!
> 
> The good news here is that if I *did* buy one as a glove-box light, I would definitely fit it with Lithium primaries--no leaks and longer shelf-life, as well as better temperature range.



Yeah, it was 30s(f) and she was wearing mittens (another reason I wanted that strap) so there wasn't much heat getting too the light from her hands.

I hope it behaves better for cold weather running with rechargeables in it. It was still really bright so I couldn't at the time imagine it was a battery issue. Shows what I know.

JB


----------



## Lexel (Dec 22, 2016)

*Re: Headlamp Mods for Waist Light*

I saw your CAD pictures and thought, why not buy 2 Skilhunt H03 one with TIR one with reflector

instead of using the tube for battery you screw 2 heads on the tube in the angle you need
of couse you can adjust the angle as you want if you solder the cable directly on the driver boards
the picture shows the long tube, 
but the BLF A6 short works better as you see on original tube the left head is not over the o-ring 

of course you could sand down the original long tube for the 2. head to fit the o-ring and lock in the angle you want,
same for short tube sand down for the angle if screwed tight
then you can insert some sort of dummy battery to make contact with the positive contacts and tube





I did a short tube mod here
http://www.candlepowerforums.com/vb...-short-battery-tube-lighweight-mod&highlight=


----------



## WigglyTheGreat (Dec 22, 2016)

*Re: Headlamp Mods for Waist Light*



ThinAirDesigns said:


> That's great info Wiggly -- thanks.I'm really wishing the Spark SG6 weren't gone (going?) as it looked like it was a 'mule' style (not sure ... all new to me). I'm hoping that I can mod at least one of the H03s that I've ordered to replace the TIR lens with something clear and still retain weather resistance - it sure makes sense if one wants to avoid the visual 'bounce' that you and lampeDépêche have talked about. We'll see. Too bad the case design of the Zebra just doesn't lend itself to my structural mods as well as the Spark or Skilhunt do.Is there some particular reason you prefer waist over chest mount? Is it more stable or out of the way or better shadows on the trail?Thanks again. Appreciate the input from everyone.JB


I didn't really care for the feel of the gopro chest mount and also there was some arm shadowing going on depending on where your arms are during a run. Mainly it feels more comfortable on my waist and I can easily forget they are there on the waist. I think I could easily mount 2 Zebralights on the waist and might try it out when I get chance. One Mule and one floody might work together well. I have found way to mount them to my running belt which should work even with 2 lights. Will try it out soon and see how it goes. I also wonder if mounting 2 Zebralights on one headstrap side by side will work on the waist if they are aimed properly. Maybe mount them so that they are head to head on the strap so they would be aimed close to center and the aim would be forward. Two 18650s lights on waist so you can split the output and adjust beam and gain runtime over just one. Just some ideas to think about and will try it out.


----------



## ThinAirDesigns (Dec 23, 2016)

*Re: Headlamp Mods for Waist Light*



WigglyTheGreat said:


> One Mule and one floody might work together well.



That's sort of what I'm thinking as well and hope I can make that work.

Thanks for sharing your experience.

JB


----------



## ThinAirDesigns (Dec 23, 2016)

*Re: Headlamp Mods for Waist Light*



Lexel said:


> I saw your CAD pictures and thought, why not buy 2 Skilhunt H03 one with TIR one with reflector



One flood and one reflector was my original plan (though originally I hoped to use the SG6). With some advice from folks here on the forum (and some experimenting to confirm), I'm thinking now that a waist mounted reflector would likely bounce the beam way out front and be near useless. I'm leaning more towards one mule and one TIR, but we'll see how it goes.

It was your short tube mod thread that originally got me thinking about this configuration. Thanks for the spark.

JB


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## ThinAirDesigns (Dec 24, 2016)

*Re: Headlamp Mods for Waist Light*



Lexel said:


> ...but the BLF A6 short works better ...



Lexel, your short tube mod suggestion is likely the simplest way to go. Would you mind confirming for me that the tube being sold in the following link is the appropriate short tube for my H03? I want to make sure and get the right one the first time.

http://www.banggood.com/BLF-A6-Astr...dy-Extension-Tube-p-1012718.html?rmmds=search

Thanks
JB


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## ThinAirDesigns (Dec 24, 2016)

*Re: Headlamp Mods for Waist Light*

Lexel, in your short tube mod thread you have the following picture:






Do the lenses you show above fit into the H03? If so where would I look to buy them? Per the suggestions of others in this thread, I'm thinking of getting rid of the TIR lens in one of the H03 pair and putting something more clear in to 'mule' modify it. Suggestions?

Thanks
JB


----------



## Lexel (Dec 25, 2016)

*Re: Headlamp Mods for Waist Light*

Its that BG tube A6 model

link to Micro textured lens 
http://budgetlightforum.com/node/49912

AR lens a bit thicker
http://www.kaidomain.com/p/S004331.14mm-D-x-1_6mm-T-AR-Coated-Lens-1-pc

The AR lens from my Jetbeam Jet-1 MK fits perfectly 

the micro tectured is a bit thicker but I got only one for my Eagle Exe X2R
he started later to cut different sizes


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## ThinAirDesigns (Dec 25, 2016)

*Re: Headlamp Mods for Waist Light*

THANKS Lexel.

Ordered lenses and tubes.

JB


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## ThinAirDesigns (Dec 25, 2016)

*Battery options for the double H03 waist light*

So I've got my lights ordered (2 Skilhunt H03 nw) and I've ordered up a couple short tubes and lenses to have to play with per Lexel. If those tubes work out it will save me a bunch of machining (Thanks Lexel). I also have a Nitecore D4 on order (hopefully a genuine model).

My thoughts turn to batteries. I have time to research this separately since each H03 comes with a battery so I'll have two when they arrive.

So remember that I'm powering these two H03s *externally* now so the battery options are limitless. I'm pretty much a battery dumbass so I'm hoping I can mooch off the local knowledge. 

Here's the generic question: The specs say these lights will run from 2.7v to 8.4v. This means in my external packs I have the option of parallel 18650s (3.7v option) as well as serial (7.4v option). The battery packs will also be waist mounted with no more than 24" of cable (most likely less). There will be of course less wiring losses at the higher voltage (haven't calculated those) but the serial option comes with it's own (minor) complications ... must have even number of cells, etc.

(As an aside, I plan to make up at least a couple size packs if I like the way the light works (packaging ideas to come). A small set (4 or so cells) for short training runs and a larger set for all night races.)

Are there significant reasons to go 7.4v on the packs since I can?

Thanks
JB


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## Lexel (Dec 26, 2016)

*Re: Battery options for the double H03 waist light*

The light switches on higher voltage to a buck converter

on a single cell it uses a linear converter on low voltage and switches to buck as soon as it can save current drawn from the battery

I tested the light on Turbo 2 500 lumens mode
single cell it draws 1.25A at 3.3V below that the current and brightness decreases as the light is in linear regulation which gets limited by the LED voltage getting bigger than supply voltage

if the voltage gets higher the current starts to drop as it switches to buck converter

for Turbo 1 the linear voltage is higher

so you got a smart driver and can go for a 7.4V battery pack

I am not sure if the light provides low voltage protection for 2 3.7V batteries so protected batteries are a good option


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## ThinAirDesigns (Dec 28, 2016)

*Re: Battery options for the double H03 waist light*



Lexel said:


> ...so you got a smart driver and can go for a 7.4V battery pack




Thanks Lexel. Would you recommend that I do serial up and go to 7.4v on the packs? Is there some reason within the light that this would be better or is the only difference the small transmission losses in the short cable from battery to light?



> I am not sure if the light provides low voltage protection for 2 3.7V batteries so protected batteries are a good option



Yes ... I'm planning on protected batteries in the pack.

Thanks
JB


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## ThinAirDesigns (Jan 5, 2017)

*Nitecore D4 arrived*

Nitecore D4 charger arrived from Zapals.com ($17.99). Quite happy it's genuine.

Thanks to Lexel for making it possible to tell a real from fake.

Looking forward to my H03s arriving.

JB


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## ThinAirDesigns (Jan 6, 2017)

*Skilhunt H03nw arrived*

So my 2 Skilhunt H03nw headlamps arrived today. Purchased from Gearbest on sale. Prompt shipping. No issues and currently they function just as advertised out of the box.

They are currently both equipped with the TIR lens (these are not the R or F versions). Originally I had thought I would want one TIR and one reflector equipped (R version) for my 'twin' waist-light application, but the forum knowledge-base here convinced me that I wouldn't want too much throw because it would be annoyingly bouncy. Thus the two TIR lights are going to be used either as is (with one aimed higher than the other), or the lower aimed light will be 'muled' out with a clear lens (ordered but not arrived). 

In simple 'out of the box' headlamp mode I went running with one of the units tonight and also have done some testing in and outside the house. I also taped the two units together in the planned 'offset angle' configuration and toyed with that just in handheld mode on the trail (no waist-belt made yet).

I am playing with the lights in two different battery configurations. an NCR18650GA 3500mah (unprotected) and two Nitecore 650mah RCR123s (also unprotected). I've chosen these two configurations intentionally as a way to compare performance/heat/etc. in the 3.7v and the 7.4v regimes. I will be using an external battery pack, so with the H03 allowing both voltages I want to know if anything jumps out (good or bad) in the comparisons.

Initial impressions:

I'm super glad I didn't order one of the lights in an "R" version. For my purposes the TIR has *plenty* of throw and yet no 'hot spot' in the application I'm using it for. Thanks to the folks here who educated me and made the suggestion that I not go "R". It will be interesting to see what a clear lens will do for the low angle unit, but if I had to live with the two TIRs, I would probably be a pretty happy camper.

The unit with the 2 RCR123s (7.4v config) is *noticeably* brighter than the 3.7 config -- especially in T1, T2 and H1. This surprised me (perhaps it shouldn't have) as I expected the circuitry to adapt to the voltage difference and not just throw the extra power at the LED. Since I'm no EE, I can't say what's happening other than it is a *striking* difference. It's enough of a difference that I'm a tad worried about the heat produced in Turbo 2 mode (it's T2 and H1 that I hope to use long term). 

To test my heat concerns, I set the 2 cell unit on T2 and let it run. Every 10 minutes I both picked the unit up and felt the case (I have no IR thermometer) and took a picture to compare brightness. The heat was such that I could handle the unit with no issues, however if I were to grip it *very* tight, right on the cooling fins it would eventually become a bit uncomfortable (though no danger of melting or burning anything touching it). The unit ran for 50 minutes with no discernible drop in brightness (by comparing pictures). At 53 minutes it just shut down totally all at once - no slow dimming at all. I thought perhaps this might be some sort of thermal shutdown, however dropping in a fresh NCR18650GA immediately showed the light to be in perfect working order. Dropping the 2 RCR123s back into my D4 charger showed them to be totally empty. It appears that the H03 unit either has no thermal shutdown in T2 mode, or else heatwise it can run OK (at least for 50 minutes) in T2 at the 2 cell voltage.

The single cell config (3.7v) is not only significantly less bright than the 7.4v, but there isn't a great difference visually between T1 and T2 whereas with the 7.4 you sort of go "Wow" when you click up into T1. The heat produced in T2 is noticeably less (still very warm, but never reaching uncomfortable even when gripping tightly).

From the above (admittedly short term) testing, it appears that the unit handles the higher voltage just fine (as they promised) and that it give me a nice boost in lumens over the 3.7v while not exceeding any safety heat threshold. My current thoughts is that my battery packs will be in the 7.4v config.

More as I learn more.

JB


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## YahFargo (Jan 7, 2017)

*Re: Skilhunt H03nw arrived*

If you power both lights with rcr that's 4 batteries every 50 minutes. If you need the light for say 8 hours that's 32 rcrs! Might need to push a wheelbarrow with all your batteries :thumbsup:


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## ThinAirDesigns (Jan 7, 2017)

*Re: Skilhunt H03nw arrived*



YahFargo said:


> If you power both lights with rcr that's 4 batteries every 50 minutes. If you need the light for say 8 hours that's 32 rcrs! Might need to push a wheelbarrow with all your batteries :thumbsup:



Might want to read the thread (or even just look at the pictures). 

JB


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## Lexel (Jan 8, 2017)

*Re: Skilhunt H03nw arrived*

He uses an external battery pack with at least 2 18650.
the lights step down from turbo, so he gets about 3 hours from 2 18650 both running at high.

for the down light he wont need a big output


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## ThinAirDesigns (Jan 8, 2017)

*Re: Skilhunt H03nw arrived*



Lexel said:


> He uses an external battery pack with at least 2 18650.
> the lights step down from turbo, so he gets about 3 hours from 2 18650 both running at high.
> 
> for the down light he wont need a big output



Yep -- my '2 pack' will be for shorter night training runs. I will also have 4 or 6 packs (again 18650) for the longer night races. 4 will almost always work fine as I can pick up a new one along the way, but I have one event that I must run the entire night without resupply and I will need decide whether to carry a spare pack or build a bigger pack. Spare is almost assuredly the better choice (as it provides redundancy).

JB


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## ThinAirDesigns (Jan 8, 2017)

*Re: Skilhunt H03nw arrived*

I'm beginning to think I'm going to have to come up with a different way to grab onto the light itself other than the silicone holder provided with the light.

If you route the strap through the silicone holder like it's designed to be done (see below), there is so much stretch/flex in the holder (primarily at the red arrow) that the light bounces like crazy on rough terrain:







Reading on this forum somewhere, someone suggested routing the webbing actually *through* the loops where the light goes. I tried this and what a difference. If I were using these as headlamps for running I would certainly do that as it made the light both more comfortable and totally stable on the head (see below). It was also way more comfortable as those sharp corners (red arrow above) are no longer digging into the forehead.











The problem I see with this arrangement for my waist light is that it's insulates part of the aluminum case and I wonder if it might contribute to heat failures. After all, I have two heat producing heads that will be mounted on only one (shortened) case. Insulating some of that case seems like it could be a bad idea.

Still thinking.

JB


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## Lexel (Jan 9, 2017)

*Re: Skilhunt H03nw arrived*

I am sure you will be fine running one head in High 2

I got a Nitecore P12 which gets a lot hotter than the H03 does on Turbo 
I measured 60dC on my P12 head before the temperature stabilizes

the skilhunt keeps a lot cooler and most heat is radiated by the fins on the head

the tube of the light is the thinnest I have seen so far it will not transfer much heat at all


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## ThinAirDesigns (Jan 11, 2017)

*Re: Skilhunt H03nw arrived*



Lexel said:


> I am sure you will be fine running one head in High 2



I suspect that is correct. I haven't yet received my clear lenses so I don't yet know what the 'muled' out downward angled light will look like on the different settings. I'm hoping it can run turned down a bit.



> the skilhunt keeps a lot cooler and most heat is radiated by the fins on the head



Good to know. I have nothing to compare it to. Thanks



> the tube of the light is the thinnest I have seen so far it will not transfer much heat at all



They also have not arrived, but I won't be using the stock tube but rather the short tube (BLF-A6). Hope it is also thin.

JB


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## ThinAirDesigns (Jan 19, 2017)

*Re: Skilhunt H03nw arrived*

I received the short tubes today so I went to work pulling the Skilhunts apart. Even though the tube/head interface was sealed with red Loctite, the combo of a heatgun and a tape covered crescent wrench had them separated in no time.

I have not rearranged the O rings yet (per Lexel's excellent suggestions) and I still haven't received the clear lens, but I did want to see how the dual set fit into the silicone holder in the short tube configuration.

Now working on the best way to hook up external battery packs to the dual light.


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## ThinAirDesigns (Jan 20, 2017)

*Re: Skilhunt H03nw arrived*

Pulled the TIR lens out of the H03 to preview what a 'mule' version would look like (still haven't received clear lenses).

Two issues:

1: The LED board is held in place near the rear of the cavity via the TIR lens. The clear lens is of course not going to hold it in place at all so that would have to be solved.

2: The shadow cast by the metal case (in large circle) is far more stark than the softer circle cast by the TIR lens. This crisp edge is going to make bouncing motion *more* noticeable rather than less - counter to my goal.

I'm thinking currently I won't be using my clear lenses. 

JB


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## Lexel (Jan 21, 2017)

*Re: Skilhunt H03nw arrived*

I did an emitter swap to eliminate the yellow green tint my light came
now an U3-3D in there and I love it
the star in the light has a DTP which is nice to know, so the LED keeps cooler than on a regular copper star

for a mule I would suggest a copper spacer and spacer around the LED to push the star to the body


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## ThinAirDesigns (Jan 21, 2017)

*Re: Skilhunt H03nw arrived*

Yeah -- I was trying to figure out how heat transfer would work if I moved the LED forwards.

JB


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## ThinAirDesigns (Jan 30, 2017)

*18650 battery pack assistance needed.*

(I posted this over in the 'Batteries Included' forum and got zero response to these questions. I'm posting here just in case someone here has the answers - thanks)
____________________________________________

Hi folks, I could use some basic 18650 battery pack / charger assistance. Thanks in advance.

For background, I am no EE (not close) but have a basic working knowledge of simpler electronics, can read a simple diagram and have excellent soldering skills. 

I'm going to be building a custom 7.4v pack(s) and using it to simultaneously power 2 Shilhunt H03 lights. 

Though not identical (smaller bottle), the packaging of the battery pack will be something like the picture below. 







I will be using these belt worn packs / lights for long technical trail runs (ultra-marathons) through the night where there is no chance for resupply and stopping to change out batteries regularly is not an acceptable option for me.

Speed charging is not needed. If the pack charges in 10 - 12 hours I'm happy.

For the purpose of my questions, assume from 6 to 10 cells in 2s config (at least 3,000mah cells)

My questions relate mostly to safety -- I understand the basic 'whats' and whys' of lithium battery safety in a single cell configuration, but I'm not nearly as clear/certain once I start stacking cells into a pack. I see larger packs with BMS circuitry (balancing leads, etc.) and I understand why that is done. I also see smaller packs from lighting companies such as Lupine, Gloworm, etc. where there are no balancing leads (like the pack pictured above).

I don't want unneeded complications, but neither do I want a pack lighting my belt on fire because I was a dumbass during design and construction. So ... I've come to the experts.


Questions:

1: What sort of circuit protection should be included in the pack? I understand where/how to purchase and install a small PCB between the batteries and the port - is this enough? 

2: Protected cells? Unprotected cells? 

3: If one goes with pack level PCB protection rather than cell level protection, does cell balance become a capacity / safety issue without balancing taps and a BMS?

4: Does the option of pack level vs cell level protection alter the sort of charger recommended?

5: With a relatively small pack like this, will a simple charger such as this one from Magicshine do the trick safely?






Thanks.

JB


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## Lexel (Jan 31, 2017)

*Re: 18650 battery pack assistance needed.*

I would go with protected cells and a small balance charger like this
http://www.banggood.com/Charsoon-DC...ith-Power-Adapter-p-1081892.html?rmmds=search


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## ThinAirDesigns (Jan 31, 2017)

*Re: 18650 battery pack assistance needed.*

Thanks for that recommendation Lexel.

JB


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## xcandrew (Feb 1, 2017)

*Re: 18650 battery pack assistance needed.*

This might be something you already know, but with homemade battery packs and running, you'll have to be very careful with strain relief and good cords. Do not underestimate the fatigue failure potential of cords when running and when the cord is basically unsupported between the lighthead and battery pack. I had a long learning experience when I was running a homemade external battery setup on my Princeton Tec Eos more than a decade ago, where I'd have the cord break every several days, and then I'd make improvements with different cables, shrink wraps, and strain relief setups, and then keep reiterating and fixing stuff. Then cords that kept breaking on the then new Magicshine 808 P7 lights half a dozen years (?) ago (though the bikers that used the light didn't have the same complaints). Now I just use an off the shelf setup and prefer to keep the battery pack on my Yinding/Gemini on the back of the headstrap so there isn't cable flapping around.

The bounce with every footstep when running, especially when the battery pack is on your body, puts way more flex cycles into the cords than use on a bike for example. Not sure how your waist belt setup will look like, but be careful of unsupported cord. Make sure the strain relief isn't too stiff so the cord breaks at the edge of the strain relief. Not that you'll have this problem, but something as little as the extra stiffness of the solder on a repaired cord that is bouncing around from running, even with good heat shrink on it, will produce a stress riser that will cause an eventual failure, at least for the typical 22 AWG cords used in lights like Magicshine/Gemini/Gloworm. Why not just get an off-the-shelf battery pack? You can get 6 and 8 cell packs from Magicshine or Gemini. I'd personally just get two off the shelf 4 cell batteries if you need that capacity, so if one fails, you still have another. Switching between batteries can easily be done on the run.


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## ThinAirDesigns (Feb 1, 2017)

*Re: 18650 battery pack assistance needed.*

Thanks for the input xcandrew. 

Excellent points. I have many years of design experience in the motorsports fields where vibration and fatigue are primary reasons for failure. The fewer cables and connections, the fewer failure points -- all true.

As to the "why not just get an off the shelf battery pack?" question, the answer is multlilayered, but here is the biggest one:

I don't want to carry any more than I have to when running 75 miles unsupported through steep, technical mountain terrain. I have found none of the commercial packs you mention to be using anything close to the high capacity cells that have been available for some time now. For instance, the Magicshine MJ-6036 uses 6 2200mah cells and weighs 18oz. I would need to carry 4 of those (for a total of nearly 5 lbs of battery) to feed my light for the needed 14 hour stretch. The bare NCR18650b cells for that same capacity weight barely over a pound and a half and I certainly can package them quite nicely with a one lb budget -- cutting my battery weight by basically half. Carrying an extra 2.5lbs over 54,000ft of vertical change (my next running challenge) is what we call in engineering ... "less than ideal". 

(and as an aside, on the terrain I'm running, switching between batteries "on the run" is definitely not practical)

Thanks again -- your concerns are well thought out and valid.

JB


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## dirkomatic (Feb 19, 2017)

*Re: 18650 battery pack assistance needed.*

What did you end up using for a battery pack? I would like to make something very similar for mounting on a helmet, but it would need to withstand wet conditions. It seems the 4 cell pack is easily found, but I really would like a 2 cell pack which can easily swap out 18650s.


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## ThinAirDesigns (Feb 19, 2017)

*Re: 18650 battery pack assistance needed.*



dirkomatic said:


> What did you end up using for a battery pack? I would like to make something very similar for mounting on a helmet, but it would need to withstand wet conditions. It seems the 4 cell pack is easily found, but I really would like a 2 cell pack which can easily swap out 18650s.



Depends on what you mean by "wet". I purchased two of these to use for my shorter runs -- I have no qualms with them in the rain, but wouldn't want be ducking through sumps in caves with them.


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## dirkomatic (Feb 19, 2017)

*Re: 18650 battery pack assistance needed.*

Caving is what I would be doing... I saw those c & b seen packs. Is there a US source for them?

Maybe I'll just stick to the two light setup.


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## ThinAirDesigns (Feb 19, 2017)

*Re: 18650 battery pack assistance needed.*

No US source -- direct from C & B seen.


----------

