Cavers - The StenLight, Ultimate 2x3W LED Headlamp

[jtice]

DAMNIT !!!!!!!!
I wish something would be done about the quotes locking up browsers AAAAAAAAAAAAAARRRRRRRRRGGGGGGGGGG!!!!!

ok,,, as I was saying...
jtice goes to retype....


Thanks for the quick and thorough response.

Perhaps I'm wrong, but I was under the impression that the Li-Polymer batteries were somewhat flexible. I envisioned them conforming to the curvature of the inside of the helmet. If they do, I think there'd be enough clearance so that the straps wouldn't touch the batteries.

hmm, I have never heard of actual flexible cells,
that would be really cool if they are though !
Let me know if you can confirm that, and how flexible they are.

Interesting. I didn't know about the venting. That rules out dipping the whole battery pack in that rubber/vinyl stuff. What type of epoxy is appropriate for coating the PCB? Where is it available?

I THINK the Stenlight packs are dipped in rubber,
but I am not sure what portions of them are.
Also, I dont know if that would hold back the vented gas or not.
Would be nice to know, I would like to use it if its safe.

So the matching process is just making sure that the 2 batteries are in the same state of charge? That's not so bad. I was afraid I'd have to find 2 batteries with *exactly* the same discharge curve or something.

Its not a big deal with Li-Ions,
due to the voltage representing the charge state real well.
Since you are buying them new, just get them the same voltage.
Now, adding a new cell to a 2 month old one is another story.
Then they would probably have diff. discharge curves.

Probably not that much. I figured it'd be good to have more than one battery pack, and I thought it'd be fun to build the 2nd one myself. If the 6000mAh ones will fit, I'll have a very comfortable margin of safety.

Oh, I am not saying it wouldnt be nice
more is always better, especially if you arent increasing the packs weight/size much.
Keep us posted on how it goes !!!

~John

[cue003]

John, I am assuming the Lumidrives/L20pt etc mentioned above is the maker of the optics right? Where did you buy the 6 degree?

I know you had to shim the 25 degree version that you have, but did you have to shim the 6 degree as well? I still haven't gotten around to buying this headlamp yet. It is on my list ... just a matter of time.

Curtis

[jtice]

Yes, those are the manufactures of the optics.

They were sent to me for testing,
so I am not sure where they can be bought, sorry.

Shimming,
well, I just left it shimmed for all those,
it seemed to work well, I didnt notice any holes, etc in the beams due to not being focused.

I have heard alot of optics actually look better sliiiiiighly shimmed

~John

[niemidc]

To comment further on Mark's questions and JTice's answers:

JTice: it is all those Emoticons in the reply window that lock up your browser. I use Mozilla on Linux, and it pegs my CPU meter, I'm sure it's the same issue.

Our connectors are tin-plated, not stainless steel (stainless steel actually has rather mediocre electrical conductivity). Mark, dielectric grease is a really good suggestion -- I recently happen to have done an immersion test with it in fresh and salt water and it greatly cuts down the amount of current that flows (and hence greatly reduces the rate of galvanic corrosion). I'd recommend it for anyone planning on having their StenLight or its battery connection spend much time underwater.

Also at automotive supply stores, you can get electrical contact cleaners that should help to shine up the contacts. Probably a good idea if you already have some mileage on your connectors before you start using the dielectric grease.

That laptop battery is a lot of Li-polymer for the money. But it is BIIIG. I really doubt it is flexible, it is fairly thick. It is probably much harder than our stock batteries (not rubber coated). And you'll need at least two to get up to a reasonable voltage to power a StenLight. Might make a nice pack for a long pocket.

The vents on Li Ion and Li Polymer batteries (and most nicads and NiMH cells too) are only used in an emergency, like if you were to short it with no protection circuit or something equally traumatic. They don't vent routinely, in fact it is probably darn near impossible to make them vent while on the protection circuit. A hard, tight case covering the vents would indeed be a bad idea. Our case is more like a balloon -- it might puff up, and might pop, but rubber isn't going to prevent the vent from doing its job.

Cell matching is important if you want the battery to discharge in an orderly way and give you plenty of warning as they start getting low. If they are badly matched, one will still be sitting up at 3.3V while the other drops to 2.3 and cuts off the protection circuit for the whole battery, and your light goes totally dark suddenly. We had this problem in the prototype batteries, which were not well matched like the production StenLight batteries are. Also, if matching is poor you only get the lower of the two capacities, effectively. Definitely get two of the same type; but to get true matching you need to get something sold as a 2-cell battery, and even then you have to verify it.

And as JTice pointed out, it really isn't safe to put anything inside your helmet you wouldn't mind having pressed firmly against your skull. If it was truly small and flexible and flat, that wouldn't be so bad, but this is not a little battery -- in fact I rather doubt it would fit.

Welcome to the list! I am fairly new here myself.

[PeLu]

David and John: I too suffered from the browser lockup and I lost several long posts (some people might think: thanks god!)
And I never use (animated) emoticons and remove them even from the quoted text.

Our connectors are tin-plated, not stainless steel (stainless steel actually has rather mediocre electrical conductivity).

That does not matter. The SpeleoTechnics lamps are one of the most relyable electric caving lights and use (custom) stainless steel connectors since decades. The connectors you use on the StenLight is probably good for some 30A, maybe more. The same in stainless steel probably for 10A. More than enough. In practical life I experienced that it is more important that the contacts are easy to clean and that some thin layers wear off. And stainless steel is easy to clean.

Even as good as the stock battery life is, I want more (doesn't everyone?).

At least I do not want to carry more on my hardhat.

Putting a battery or a single cell into your helmet has the following drawbacks:
You decrease the crush zone. This might be OK if you use your hardhat mainly to protect the cave from your head (not making the ceiling in a cave bloody .-) That means in more or less horizontal caves.
This has been written in here before.
You also decrease ventilation.
And there is not very much space.
The helmet's balance will not be as good as with a back mounted pack (or better, depends).

IMHO the only thing inside your helmet (except your head) should be a space blanket or better a garbage bag.

These LiPoly cells usually have a lower energy density than normal LiIon cells, but the one you mentioned comes close.
They could be bent to some degree, but probably not enough for this application.

I would go for 4 18650 cells, which will give a pack similar sized as the Petzl Duo's pack. How long will you stay on Turbo (I assume that it will work nicely in alpine caves). You could shape the four cells so that it fits perfectly to the back of your helmet.

I don't really want to increase the bulk of the helmet, but I don't really want to install a hard, unforgiving battery pack inside the helmet either.

What I'm dreaming since more than a quarter century is a helmet which has a battery compartment built into the case, no additional weight and perfectly protected battery. I also know that it never will come true.

I was considering putting 2 (or 3 or 4) of these in the crush-space inside my helmet.

4 of them will weight about 600g, more than a good helmet itself.

From what I understand, Li-Ion batteries need to be protected from overcharge/overdrain,

It is good enough to leave the charge protection with the charger. (but it comes free with the protection anyway).

Do battery used in series have to be matched in some way

You will need some balancing circuit anyway. I have batteries which were pretty well matched when new and drifted apart later. A balancing circuit has to be included in the protection.

If I used 4 batteries, would the efficiency be different with a 2p2s configuration vs. a 4s setup?

The first one will be more efficient and you have some discharge warning. (with 4 cells in series you get the lowest capacity from all cells and the buck converter is slightly less efficient).

Has anyone tried automotive dielectric grease yet?

I use it all the time and I have mentioned it on CPF too many times already. Especially on higher current connections (we use lots of rotary hammers). It only collects mud. And runs away in hot climates.

[cy]

niemidc-


Hello- i have a question that has not really been addressed- I can only purchase lights that are truly waterproof- invariably they will be taken through sumps- often as deep as 100 feet- your case is so close to being perfect, but I am worried about the wiring bulkhead connection at the lighthead- I think I read that it was only waterproof to a few meters- what is your opinion on the depth rating- and any thoughts on improving the bulkead? (The battery is not a problem- Easy to build waterproof battery containers..._

J

for diving....

[jtice]

wow, lots of comments sence I posted.
I will try to touch on all of them...

I dont know whats doing the lockups.
I know that alot of the time, if I use quotes in PMs they lockup,
but not all the time,

Overal, I really like the 2x18650 pack,
its pretty small, and balances pretty nice when on the back of the helmet.
I havent really noticed that I am hitting it on anything yet.

I am planning on building a few packs,
I like the small connectors, and plan to make other lights, etc run off them.
A 3x18650 pack might be the answer for you.
I plan on making one of those also, I think with one of those I could last an entire weekend.
The 2x18650 pack can last me a weekend now, but the added runtime of the 3x18650 pack would be very reassuring.

The thing I dont like about the thin cells you are talking about,
is the fact that I could probably take one in my hand, and break it in half.
The 18650 cells are going to be much more durable, and crush resistant.
I built mine into a hard clam shell, but I think they would have been fine just heatshrunk a few times.

David is probably right about the rubber coating.
Even though its covering the vents, its not going to be able to hold the gas back.
Though, AFAIK, they do vent with regular use, although very little.
(even open a freshly used light and sniff it?) Its mainly with primary cells though.

I will have to look into that rubber dip stuff,
anyone know a good priced place to get it?

I have never heard of a balancing circuit.
Have anymore info on that?
My understanding was, that if you bought two new cells.
got them balanced well, that they should stay that way.

~John

[gearfreak]

I have never heard of a balancing circuit.
Have anymore info on that?

Not sure if this is what was being talked about- but I have come across these being advertised for model aircraft LiPo's
Dualsky battery balancer

And here is their blurb:
To 3S balancer for 3 cells pack (11.1v),the total volt value is settled to 12.6V,during charging, if the volt of one cell is over 4.25V,the balancer will begin to work, it will help the cell to consume the unwanted volt, but the other two cells are still charging. Once the total volt value is up to 12.6V,it will stop to charge.

To the first time using the balancer, perhaps you will find the volt of cells is different, but after 3 times or more, you will find the volt of cells is very close. So it can protect the cells not over charge and balance the cells volts.

[whitmerm]

The thing I dont like about the thin cells you are talking about,
is the fact that I could probably take one in my hand, and break it in half.

As far as rigid, candy-bar shaped batteries go, I agree with you completely. That'd be a very weak geometry for this application. They'd have to be enclosed in a pelican case or equivalent.


I think I found the source of my impression that these batteries are flexible. On this page:

http://www.batteryspace.com/index.as...Custom&ID=3#14

under the heading "What is the performance of Polymer Lithium ion battery?", they say "Battery is transmutable and can be crooked: the maximum angle is 90[degrees]"

Now, I've never actually handled one of these batteries, and much of the grammar on that page looks like it was poorly translated from another language, but my guess is that it means these batteries can be bent without damaging them.

I've emailed the company asking for more information. I'll post whatever I learn. In the mean time, does anyone have first-hand experience with these polymer Li-Ion cells?

I will have to look into that rubber dip stuff,
anyone know a good priced place to get it?

I can't find a link, but I remember seeing some stuff like that at Home Depot. It was in the section with electrician's tools. Basically, it was a can of goo that you could dip the handles of pliers in to give them a non-slip, non-conductive coating. I've never played with the stuff, but it looked like it might work here.

Anybody know where to get good abraision-resistant heatshrink?

--Mark

[PeLu]

I quote myself, it looks that my posts are too long and people do not read them .-)

They could be bent to some degree, but probably not enough for this application

90° might be a too general rule, a minimum radius would be more hlepful. Anyway, I think maybe they could be fitted around the back of the helmet, two of them and some case above.

Balancing circuit: I do have several 7.2V packs containing 2, 4 and 6 cells and some of them came out of balance (after as few as 10 cycles). But I have to say that these were relatively cheap ones. IMHO a balancing cicuit is mandatory (actually I prefer lights which run on single LiIon cells, but sometimes there is no choice).
I do have several packs I made for the Melzer Radon and use them now for the StenLight, too.
The problem is, people just say if a pack is 'protected' and do not tell what the ciruit is actually doing. Many of the cheap protection ciruits do unecessary things instead of the real stuff.

More than 2-cell LiIon packs: They have the big drawback that you do not have a warning when the battery gets low. This is absolutely mandatory for caving. There was quite some uproar when the SpeleoTechnics appeared with LiIon cells. Even when you say you are only using the capacity partly, one day the pack will not be charged in full (for whatever reason) and you experience yourself in the dark at an unpleasant spot. Been there, done that, survived with luck. If it can be avoided....

cy: I cannot see a stenlight on your nice cavediving picture....

BTW, SpeleoTechnics is using PU to encase their LiIon cells. They make a quite nice package out of one rectangular 6Ah cell.

Anybody know where to get good abraision-resistant heatshrink?

Try a bicycle inner tube instead (it is easy for me, I do have plenty of them in different sizes). I put one on the bare cells, then good shrink tube(s), and at last another layer of inner tube, which can be changed when worn. And you can put the socket underneath when not used. You might easily encase the whole battery in PU or similar amterial, in case the valve vents, it will not be another real resistance for the gasses. I do not know the actual values for LiIon cells, but with other cells the pressure for activation the valve is quite high. And the encasing material might keep the 'goo' in, also not bad.
Heatshrink tubing: usually the one with the higher shrink ratio (1:3) is thicker and more resistant.

As mentioned above, I use several cheap packs for videocams. These could be bought at ebay for almost nothing. They have a a quite sturdy pastic housing, so I just have to make them waterproof and and add my unavoidable bicycle inner tube. Of course they are behind in performance to the original StenLight packs.

[niemidc]

Not sure if this is what was being talked about- but I have come across these being advertised for model aircraft LiPo's
Dualsky battery balancer

And here is their blurb:
To 3S balancer for 3 cells pack (11.1v),the total volt value is settled to 12.6V,during charging, if the volt of one cell is over 4.25V,the balancer will begin to work, it will help the cell to consume the unwanted volt, but the other two cells are still charging. Once the total volt value is up to 12.6V,it will stop to charge.

To the first time using the balancer, perhaps you will find the volt of cells is different, but after 3 times or more, you will find the volt of cells is very close. So it can protect the cells not over charge and balance the cells volts.

The problem with this sort of balancer is that it only kicks in during the tail end of charging. If your cells are exactly the same capacity and different state of charge to begin with, it could help somewhat, but what is really needed here is a way to equalize charge near the bottom of the discharge cycle, which this device does not do.

In large batteries "flying capacitor" charge equalizers can actually redistribute charge between cells at any time. But that is not really practical in a small battery like ours.

[niemidc]

David and John: I too suffered from the browser lockup and I lost several long posts (some people might think: thanks god!)
And I never use (animated) emoticons and remove them even from the quoted text.

I meant that the "Post Icons" section, that shows up as you are composing your post, can sometimes suck up a lot of CPU, and I thought it might be the cause of John's lockup.

[cave dave]

Dar,

...The charger is the same charger, but Stenlight put their connector on it.
Which can be bought from digikey.com page 120 of their catalog...

~John

John,
What is the Digikey part number for the connector? There is a whole page full on pg 120. Will need part numbers for both the female and male part. I figure I might as well get the parts before the light arrives.

-Dave

[jtice]

John,
What is the Digikey part number for the connector? There is a whole page full on pg 120. Will need part numbers for both the female and male part. I figure I might as well get the parts before the light arrives.

-Dave

Heh, crazy timing Dave,
I happen to have them right in front of me, I was making a few adaptor/cables, etc. just now.

You need 4 parts all together.

Connection Plug Housing = 03-06-2023
Connecting Receptacle Housing = 03-06-1023
Connection Terminals (female) = 02-06-1103
Connecting Terminals (male) = 02-06-2103

Dont forget some heat shrink
About 1/2" dia. Before shrinking should work.

~John

[SilverFox]

Hello Mark,

I will jump in here and clear up some confusion about Li-Poly cells.

The cells are vacuum sealed in an aluminum pouch. The flexibility comes from the fact that they can be manufactured with bends up to 90 degrees. Once they are sealed, you can not bend them without compromising them.

Li-Poly cells have no protection at all. This requires the protection circuit to be mounted as close to the cells as possible. If the wires between your cell and the circuit were to short out, there is a very high possibility of the cell catching on fire in an explosive manner.

If you run bare cells without a protection circuit and your wires short out at the plug or elsewhere, you can easily end up with a puffed pack. If you are not quick to eliminate the short, it will catch fire even if at a low state of charge.

The Li-Poly cells are sealed. When problems arise they puff up to 3 - 4 times their normal thickness. When designing a container for them, you need to allow for this expansion. Since there isn't that much room inside your helmet, I would recommend putting the battery pack somewhere else.

The aluminum foil pouch on the Li-Poly cell is fairly easy to puncture. If the puncture is just on the surface, it renders the cell unusable. If it is deeper, it shorts the separator out and you have a shorted cell with no way to remove the short. It will puff and catch fire.

Li-Ion cells are much more robust as they are in a tin can. They are also safer because even the unprotected cells have a PTC circuit that shuts the cell down in the event of a short.

Using cells in series is not a problem. The problems arise when you go to charge them. The safest way to charge is to charge each cell independently. If you charge in series you can run into cell imbalance. There has been much discussion about balancing cells in a pack. The general agreement (right now at least) is that it is OK for the cells to be unbalanced in a discharged state. Balancing is necessary toward the end of the charge cycle to keep the voltages on each cell below 4.2 volts. Some of the RC people have 70 - 100 cycles on their packs. They notice that the packs are not in balance when discharged, but come back into balance when charging. Others have had cells puff during the first charge, indicating that they were out of balance from the factory.

I would recommend staying with Li-Ion cells, but if you want to use Li-Poly cells, I would recommend mounting the protection circuit right at the battery terminals. You could then dip the whole thing in plastic and drop it into your pocket... Just don't sit down hard...

Tom

[cave dave]

I just got mine yesterday
I also got the accessory kit. Anybody have any idea what kind of runtimes you will get on a backup 9v battery? Both Lithium and Alkaline. The Lithium 9v apparently have about 1200mAh. So theoretically you could get half the runtime as the stock battery.

http://www.batteryspace.com/index.as...odID=1618&HS=1

I like it so far, my first reaction was the low was too low, Its dimmer than a CMG infinity Ultra. If it was in the 6-8 lumen range I could see using it more. As it is I can only see using it for emergancy mode. Or while I'm not moving in cave. (sitting, eating, etc)

I'm a little disapointed that the beams aren't centered. All 3 I looked at were like that. The spot beam was not in the center of the wide beam. This makes it a bit spotchy and has a hole to the right of the spot beam. I put some writeright on and that helped with the spotchyness. It will also protect the lens. I'd try to adjust the optics but that would void the warrenty

[cave dave]

Well that last post seems a little negative. This light really is very very cool. I will say this looks like it will make a great little bike light as well.

I'm sure it will evolve a little in the future. I hope they look into putting a reflector to replace the 5 deg optic. This will increase the throw and spill at the same time. Does anybody think one of the McLux reflectors will fit?

[jtice]

cave dave,

I have a nimh 9V batt,
its rated at 7.6V 150 mAh
and it ran the Stenlight for 1.5 hours on High !!!!!!!
I will be carrying that battery with me from now on for backup.

That cell you linked to looks very nice!
I might have to get one of those!

There are many optics that will fit the Stenlight, as you can see from my photos.
I have not found any reflectors that will yet.
The IMS 17mm and McFlood will not fit.

I had a tight 5 degree optics, and wide 25 degree optic in mine.
I think im gonna swap the 5 degree with a 15 degree for a while,
I like the throw, but I could have used a wide beam a few times.
So Im gonna try that for a while.

~John

[cave dave]

I've been running a 9v Alkaline on medium for 7.5 hrs now and its still putting out usable light. The hotspot is as bright as a Tikka+, although there is much less spill. My guess is about 9 Lumens.

Occasionaly I'll flip up a mode to see if they are still accesable
Turbo was unavailable after an hour
High disappeared sometime between 4 and 7 hrs

Very impressive

i think I could do a short cave trip on just a 9v battery

I'd like it if they made a 3xCR123 carrier, It would be really light and small and the batteries are cheap off the net ($1.25ea) and pack plenty of power.

[jtice]

Wow,

Thats awsome!
The heck with my crappy nimh one.
I will have an Alk 9V with me for backup from now on.

Thanks for the info !

~John

[cave dave]

More info on the 9v alkaline. I finally turned it off after 10 hrs on medium. At that point the medium (and all higer levels) was about 50% brighter than the Lowest setting.
I asked about 9v performance on the Sten light user group and David Nemi from Sten light replied:

"Based on watt hours, a 9V alkaline should last about a quarter as long as
the lithium ion on any setting below Turbo. That is, 1-2 days on low,
about 6-8 hours on Medium, and 1-2 hours on High. 9V alkalines have
trouble putting out near an amp so I wouldn't recommend using Turbo much,
but then the purpose of the 9V adapter is to give you a small, readily
available emergency backup.- DCN"

I have some Li 9v on the way and if they arive by next weekend I'll test them out in W.Va cave using med and high as appropriate and see how they do. They are rated at 1200mAh with a max output of 100mA. (but I'm willing to push it )

[jtice]

cave-dave,

hmm caving in WV? huh? what cave are you planning to see?

These 9V cells are gonna be GREAT backups.
I wasnt expecting this much runtime,
but then, I should have known, these Stenlights are are sooooo effecient.

~John

[cave dave]

Ok I guess I could have bought a headstrap, but i didn't like the ones curently available. Stenlight hasn't released their's yet. Plus I have so many headlamps that are now obsolete so...

Black diamond headstrap and the donor light:


Closeup, blade mount has been removed. I used plastic spacers and washers to space it out:


PS jtice, i sent you an email about caving in WVA
-Cave Dave

[cy]

don't know if this has been asked before...

any chance of a special cpf group buy on stenlight?

I'm not a caver, so hard to justifiy $310
but if we could get a one time special cpf deal. more of us might go for it.

cavedave, thanks for your pic. was wondering how I'd make stenlight into a std headlamp?

I've got a 18650 2x pack just waiting for this light.

[PeLu]

I like it so far, my first reaction was the low was too low, Its dimmer than a CMG infinity Ultra. If it was in the 6-8 lumen range I could see using it more. As it is I can only see using it for emergancy mode. Or while I'm not moving in cave.

Or while climbing a rope, or, or. For me the lowest setting is quite useful for many tasks and I would miss it it it would not be there.
Even for narrow passages in white rock it is sufficient.

[jtice]

I love the low mode, and use it alot.

I have been in some tight crawlways, where my face is just a couple inches from the rock.
On medium it was blinding, low seemed just right.

I even used Low while hiking out of the woods once, it was just enough to see my feet well,
yet keep me somewhat night adapted.

cy,
I wouldnt count on a GB, I dont think there would be a sufficent number of ppl to make it worth while.

~John

[paulr]

All this modder battery pack stuff doesn't seem right for such a nicely finished product. I think it would be good to make an adapter for Sony L-series camcorder packs. These are solid little packs with up to six 18650's inside (NP-F960, 7.2v 6000 mAH, about $30 off-brand on Ebay). There's a wide assortment of chargers available for them (camcorder accessories). They come in three sizes (2, 4, or 6 cells) with the same mounting system and connectors, so you can just swap between them, i.e. use the 6 cell pack as a primary and the 2-cell pack as a backup. The 2-cell is maybe 2x the size of a 9 volt battery and is 7.2v 2000 mah or something like that. They even have microprocessors inside the pack so the camcorder can monitor the charge state, but I have no idea how the interface works.

[jtice]

Thats what I like about the Stenlights 6 to 18V input range,
I can use all sorts of packs.

These look nice, though I dont know how much I trust some off brand crap.
http://cgi.ebay.com/2-x-NP-F960-BATT...QQcmdZViewItem

Making the adaptor to hold the pack is what would be hard,
Finding an old camcorder, and ripping off the pack connection would be nice

~John

[paulr]

There are some "universal" camcorder battery chargers with interchangeable connector plates to fit different kinds of batteries. The plates are about $5 each online (adoramacamera.com). I don't remember the part number. My idea is to use the adapter plate to connect the battery to the light (solder wires onto the other side of the plate). I haven't actually tried doing anything that way yet, so no promises.

[jtice]

I have a Triton charger,
so I can charge pretty much any cell, pack etc I want.

I would just solder on a cord to the camcorder pack, and shrink wrap it.
I have all sorts of adapting cables I made for the Stenlights connectors,
including ones for the Triton, so I could just plug it right in.

This would eleminate the adaptor plates, which can get wet and muddy,
then you will be in trouble.

I had an old 7.2V pack from an old digicam,
that I wired a connector to, it was really nice, for the fact that the pack is already a hard shell.
But the pack was too old, and wouldnt charge
it was sitting in storage at about 2V :

~John