# Battery construction details & History of the USL



## js (Feb 25, 2005)

Bill gave me permission to reveal the details of my contribution to the USL: battery pack construction and design.

For now, there are no pictures, but I will be taking some over the next few days and will add them to this thread.

OK. So, to start with, for those not familiar with light design in this power range I wanted to mention that building an Aurora class light involves problems not normally at issue in a SuperBulb incan mod. You can get a much more comprehensive understanding of these things by reading Ginseng's Aurora thread and the threads of the people whom he credits in that thread and also the link which can be found in his sig line. But for an overview, here are a few of the more prominent issues:

1. Heat. No plastics need apply. No solder joints too close to the lamp will stay solid. No hot glue will keep its grip on the battery pack. In so many ways, on so many levels, heat considerations dictate the design.

2. Current. 8+ amps is a whopping rush of electrons, and few switches are up to the task, but more importantly, thin resistance welded bands of metal are no longer able to adequately electrically join batteries together. They WILL work, but will also add a non-trivial amount of resistance.

3. Batteries. This sort of goes with no. 2 above. Very few cells that are relatively small in size will deliver 8 or 9 amps and hold a decent voltage. Cells this potent are rare and must be specifically and specially manufactured.

4. Space. This ties in with all of the above. Trying to find batteries that will handle 8 amps and then joining them together all while observing proper safe distance from the heat source is difficult. Many, many factors must be balanced against each other.

5. Cost. Sure, you can have a custom body machined around everything else, but it will drive your costs through the roof unless you are doing a run of hundreds. Plus, chances are the first proto-type will have problems and won't work, which will mean another, and the proto-types are the expensive elements.

And then, of course, there are all the usual issues that go with incan light design, such as matching the battery pack to the lamp, and finding a way to hold the lamp in position, and so on.

To get a feel for the USL pack, and the key idea behind it, grab a Mag D sized light, if you have one, and then remove the switch core and head. Now take four AA alkaline batteries and push them into the back of the light. You will see that they just fit in a square or diamond shape formation. In fact, orient them so that the points of the square are top and bottom and left and right. Now remove the top battery and let the other three slide all the way to the snap ring, directly underneath the round switch opening. If you look in from the front of the light, you will see that there is a good bit of room from the round switch opening to the top of the bottom most battery. Room for a switch of the right design.

This is the essential feature of the USL battery pack design. It is simply four stacks of three AA's with one missing AA in the top stack. That is the positive battery pack terminal. Then at the back of the light there is a jumper to the leftmost stack (looking in from the back of the light). Then there is a jumper from the front end of that stack to the bottom stack, and then a jumper from the back end of the bottom stack to the rightmost stack, and thus the negative pack terminal is at the front of the rightmost stack.

*SOME CONSTRUCTION DETAILS*

The USL pack is made from 11 www.cheapbatterypacks.com 1650 mAh AA NiMH batteries. In my initial testing these cells *held* better than 1.1 volts/cell at 8.3 to 8.5 amps, or 12.1 to 12.3 volts or better for the pack. These are the best high-current AA cells available: as good as KAN 1800 4/5A's but with a bit less capacity. These cells are the main reason that the USL is a reality and not just an idea, although the KAN 1300 AA's would have been able to handle this current as well.

Now, unfortunately, the CBP 1650's are just a bit larger than, say, a Duracell or a Ray-O-Vac, and thus the Mag body needs to be bored out a small amount. Not enough to touch the threads, however, and not enough to impair the structural integrity of the light. OK, since that is not my problem, I will move on.

So, since the batteries cannot be resistance welded together for an 8 amp draw, they must be end-to-end soldered. This is a tricky operation and involves a lot of work to prepare the surfaces of the + and - contacts, then tin them, then heat up both solder puddles at once and push them together before they cool, joining them over the entire surface of the smallest contact in a minimally thick layer of solder.

I have covered the details of this operation in my TigerLight Custom Batterypack construction details thread. Anyone who is determined enough can master it, but it is a skill which takes time and practice to develope. And in the case of the USL, it is a skill which is actually necessary for the best battery pack performance. I am not the only person on CPF who can end-to-end solder batteries. Ginseng and Tweek can also do this, and there are probably others. Also, scads of people on www.rcgroups.com end-to-end solder their battery packs because they are asking them to deliver 20 or 30 amps.

After end-to-end soldering and taping and/or wrapping, the stacks are glued together using GE RTV 108 silicone adhesive and sealant. Why this and not something else? Why this, which I heard someone laughingly refer to as bathroom caulk? Simple: it is flexible and resilient and very very tenacious and strong, while at the same time being capable of withstanding very high temperatures.

Next the electrical connections are made bewteen stacks with 25 amp tinned copper braid, soldered directly to the battery contacts.

And finally, two high strand count silicone jacketed 20 gauge wires are threaded through the center of the pack and soldered to the + and - contacts at one end of the wires. At the other, a Molex micro-fit connector is attached for the charging connection, and the connector at the end of the pack resides in the space of the tail cap and the end of the mag body, since no mag spring is needed to carry current to a ground return path through the body of the light.

A 16 gauge wire is soldered to the + contact and then to one of the switch leads. Then one of the socket wires is soldered to the other switch lead, while the other socket wire is soldered directly to the - battery contact.

So as you can see, there are negligibly small amounts of resistance in the batteries and wiring and switch, which is important in a high current, high powered light. Thus, almost every bit of juice that the batteries have gets to the lamp. And what a lamp it is--but I'll leave that for someone else to tell.

I hope you guys like your USL's. Thanks, Bill, for taking on this MONUMENTAL task. I have it easy. All I have to do is build (gulp) 60 plus battery packs. hehe.


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## DaveNagy (Feb 25, 2005)

*Re: Construction secrets of the USL: why it\'s so g*

Awesome.

So, if I understand you correctly, all the cells are connected in series? Electrically equivalent to connecting all eleven cells nose to tail? (What cool light that would be. You could call it the Light Saber!)

You make 4 "stacks" of cells, then flip two of the stacks end for end so that you can attach pos-to-neg jumpers on the ends of the stacks?

You mention that these batteries are capable of 20 amps. Does that mean that, theoretically, you could power a 200W bulb off this pack? I'm not suggesting this would be a wise or prudent thing to do, I'm just wondering. /ubbthreads/images/graemlins/smile.gif Would your solder and wiring survive the experiance?

Mmmm, 7000 lumens. /ubbthreads/images/graemlins/wink.gif

-Dave


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## js (Feb 25, 2005)

*Re: Construction secrets of the USL: why it\'s so g*

Dave,

Yup. You got it.

And yes, this battery pack would deliver 20 amps, or even more. Past 25 amps continuous the copper braid would start to overheat, but not as fast as the batteries would run out of charge. hehe.

As for 200W (or 250 W *cough* = 10,000 lumens) these lamps in GY6.35 configurations don't require more current, just more _voltage_. Which means more cells in series. Like 19, for example. Check out the Ken4, for instance.


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## PlayboyJoeShmoe (Feb 25, 2005)

*Re: Construction secrets of the USL: why it\'s so g*

It's a damn shame stuff like this is so far out of my price range. I mean even if I had the light, I couldn't afford a charger.

Lucky for me, I'm not likely to ever encounter one of these in person!

And also luckily for me, I have bulbs and other stuff coming for the poormans handheld sun, the M*gBP85!

Y'all are some lucky mothers to play at this level!


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## js (Feb 25, 2005)

*Re: Construction secrets of the USL: why it\'s so g*

[ QUOTE ]
At some point I'd like to see some discussion about the care and feeding of this pack. Stuff like how fast to charge it, how often, storage tips, dangers, stuff like that. I'm sure such knowledge is old hat to many here, but not me.

[/ QUOTE ]

Not a problem.

Given that the USL will be sold with a smart charger, there aren't as many provisos and warnings. NiMH don't like to be on continuous slow charge, once they've reached peak, but a peak charger stops at--drum roll please--peak, so no issue there.

I'd say the following for now about the USL w/ Hitec CG-340 charger:

1. Don't charge a pack that was just charged in the last day or so (and has just been sitting idle). Discharge it somewhat before charging again.

2. Charge at least once every couple months.

3. Keep an eye on the pack/light while it is charging, just in case. If the battery pack starts to get HOT (and not just warm), stop the charging.

4. Feel free to charge at the maximum 1.5 amp rate. These batteries will handle that no problem.

5. Don't turn the light on while charging (!)

These are just preliminary points. I'm sure that Bill will provide instructions with the USL, including charging instructions.

But, I almost forgot the most important point:

6. When runnning the light *TURN OFF BEFORE THE LIGHT STARTS TO DIM UP RAPIDLY!* and never, ever discharge the light unattended. It could start a fire in the worst case, and in the best case, you will ruin the battery pack once it gets drawn down past .4 volts/cell. Never over-discharge a NiMH pack.


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## tvodrd (Feb 25, 2005)

*Re: Construction secrets of the USL: why it\'s so g*

Hi Jim,

It's great to know you're the "brains" behind the pack construction!!! /ubbthreads/images/graemlins/bowdown.gif Thank you for sharing the IP and in doing so, for being for being in the original spirit of CPF! 

Larry


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## js (Feb 25, 2005)

*Re: Construction secrets of the USL: why it\'s so g*

Larry,

It's great to be able to work with someone like bwaites, and it's great to rub elbows with some REALLY great, such a yourself. I am in awe of your accomplishments, quite frankly.

BTW, what does "IP" stand for in the "Thank you for sharing the IP"? Oh, wait, does that mean "intellectual property"?

Well, if so, heck yeah! I didn't do much in this arena compared to, for example, Ginseng or Kenshiro, and besides, Bill was the one with the active Aurora class light project best able to utilize the battery pack/switch configuration design.


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## DarkLight (Feb 25, 2005)

*Re: Construction secrets of the USL: why it\'s so g*

interesting stuff..


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## Starlight (Feb 25, 2005)

*Re: Construction secrets of the USL: why it\'s so g*

Jim,
You said feel free to charge at 1.5 amps, because the batteries will take it. I thought the current (no pun intended) thinking was that batteries would last longer if charged at lower overall rates. Your thoughts please.
Harry


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## bwaites (Feb 25, 2005)

*Re: Construction secrets of the USL: why it\'s so g*

Well, 

Jim has done a great job explaining the pack construction and power plant of the USL.

Because there have been so many questions and we are close to launch on this, I'll try to give a little historical perspective and insight into the thought processes and development of this light. Along with that I'll give a little personal history also.

About 2 years ago, as my brother in law prepared to ship out to Baghdad, we discussed what he had felt was needed to give him any edge there. Having served in Gulf War I, he mentioned 2 areas that he felt he personally wanted better prep and equipment than what he went with the first go around. 

1) A better personal knife. He flat didn't like the available military options and wanted a folder easily opened with one hand and closed with one hand that would stay locked in both positions. The most cost effective answer was the CRKT Blade Lock and it has served him well. Given more time, I found the Benchmade Axis Lock system knives and would probably recommend one of these now.

2. A personal illumination tool that worked, first time, every time. 

After lurking on CPF for quite a while, I settled on the red Inova X5T, and the Surefire A2/Streamlight TTL2. As he is a mechanic and electrician, I presented all three and let him choose. He took the Inova and the A2. My sons own TTL2's and they have been perfect lights for juveniles. The A2 and Inova have served perfectly in Iraq, with dozens of batteries used and no lamp replacements in the A2. In addition, I sent him with a Pelican M6 with pressure switch mounted on his A4 M16, since his unit was told that not all forces could be issued weaponlights and it was all that was available before he shipped out. It has been carried extensively and has required only one bulb replacement itself. 

After Ed had some experience with the A2, he became even more enthusiastic and I purchased one for myself. I've felt ever since that it is the culmination of a small incandescent light, with the bonus of long runtime, low output LED's. 

The introduction of high quality lights led to the awakening of the tinkerer in me that had slumbered since I left RC racing more than a decade ago. Consequently, I began to examine the many lights available and tried to make decisions about the best options. 

I soon found high output LED's, and thinking they were "IT", I purchased several LED lights, initially a MrBulk SpaceNeedleII, then an L2, then many others. Currently I have 2 SNII's, 2 SL M6LED's, a MrBulk VIP with options, a MrBulk LiOnHeart, an Inova X5T, multiple sandwich based MiniMags, and I'm waiting on an inquiry about an L4. One of my SNII's has a diffusing lens, making perhaps the most even flood light in flashlight existance.

No one could accuse me of hotwire bias at that point!

However, I noticed then, and continue to be plagued by, the obvious color problems associated with LED's. The poor color rendition of LED's under ambient light conditions leaves a lot to be desired in my view. 

As such, I began exploring more incandescent options. Already in love with the perfect incandescent beam of the A2, I began attempting to step up the power, but still get that beautiful, white beam. 

I ran across Wilkey's (CPF name Ginseng) experiments with the WelchAllyn lamps and then his development of the Aurora and became intrigued. We conversed, and he initially was going to bring a commercial version of the Aurora to market here on CPF, but that was aborted by his return to school to finish his doctorate. 

The Aurora, the first Mega Output (3000+ lumens), incandescent in a Mag style body was, and remains, the inspiration for all of the work I have done. Wilkey had originally agreed to allow me to actually use his Aurora name, but after many changes and abandoning the MagLite host, I decided to leave the Aurora designation as the progenitor to it all and rename my version.

At that point, and after all of his research, I was reluctant to allow the project to die, but personally did not have the experience or knowledge to attempt the project myself. 

With Wilkey's encouragement, I spent hours, and then days, reading about hotwires, batteries, lamps, reflectors and previous experiments. Wilkeys, Otokoyamas Perfect Mag Reflector project, Jim Sextons TigerLight mods, and many others were read and then reread as I teased out what had been tried and worked, what had been tried and didn't work, and what had been tried and then set aside for future possibilities. 

I decided that in order to use the same A type cells that the Aurora used, a new body must be designed and engineered, since the boring Wilkey had used required a new end cap solution and made the body fairly thin. Two different, rough, prototypes were made, the "MULE" and the "FAT MULE", with several bodies based on the "Mule" actually being built. One of those is actively used by the machinist who built them, 2 I still own, and Wilkey has the 4th.

One of the problems that developed, however, was that the runtime of 15-20 minutes allowed the body to become incredibly hot. Hot enough to burn skin instantly, hot enough to cook eggs, hot enough to almost start fires, which the beam could already do, as I found out one day when I set the light bezel down to insert the battery. Not realizing it was on, I left it sitting while I grabbed my briefcase, only to see smoke curling up from the newspaper under the bezel! It had been sitting for less than 20 seconds, but had burned through 6 pages of newsprint. 

The heat issue became a major problem, as I became more and more concerned with the ramifications of a light that could start fires with its beam and burn skin on contact! My wife, brilliant woman that she is, pointed out that in my profession I constantly rail against the burns caused by curling irons, (the number 1 cause of ER visits for burns of children in most studies) and yet I was propagating the possibility of burns from something that most people wouldn't even recognize as a danger! 

That was a very sobering thought, and in combination with my two sons football season, and then my oldest son's experiences while being recruited by various college football programs, I slowed down development significantly as I attempted to reconcile the dangers and problems of heat management.

By this time I had about 300 hours of development time over 6 months, and a couple thousand dollars invested into different options, most of which were dead ends. That doesn't begin to count all the time Wilkey and others saved me by telling me about their personal experimental dead ends and problems!

That will do it for Part One!

Part Two a little later!

Bill


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## js (Feb 25, 2005)

*Re: Construction secrets of the USL: why it\'s so g*

Starlight,

As far as I know, this is true, but 1.5 amps is still under a 1C charge rate, which is generally accepted as a standard rate for high rate cells according to what I've read.

Everyone else,

Bill will be adding a "History" section to this thread.

And I will be editing the inital post to add pictures and to soften the somewhat overbearing and self-important tone. I posted this all in one go without the benefit of re-writes and revisions, and it shows. Please forgive the arrogance. With some luck I will re-work and improve this thread tomorrow.


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## js (Feb 25, 2005)

*Re: Construction secrets of the USL: why it\'s so g*

Bill,

Great post. I look forward to part 2!

I have done some initial editing to *ahem* improve the tone and color of my post, and to stick to the objective: explaining the USL pack for fun and information.

Again, I'm sorry, and I hope it is now a tolerable read. Back with pictures at some point.


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## bwaites (Feb 26, 2005)

*Re: Construction secrets of the USL: why it\'s so g*

Part 2

So as I pondered the heat issue, two thoughts came to me and then several people asked about one of them.

What if I used a regulator of some type to shut the light off when it reached a dangerous temp, or at certain time?

I tinkered with the idea for a while, and then recognized that if I could set the timer, someone else could unset it!

That wouldn't work! 

I then basically was stumped. I wanted to build the light, but I NEVER wanted to have to talk to a mother whose 2 year old daughter had grabbed the flashlight and burned her hand, or worse yet, had jumped in Daddy's lap to hug daddy and laid her face against the hot bezel and burned her face while he tried to keep it out of the way without burning himself!

And then a good friend and fellow designer, Jim Sexton, who I had talked to about using regulation as he worked on a regulated Surefire M6 pack, approached me with a brilliant idea. 

Realizing that the heat idea was really cramping my design, he asked something like, "Why don't you just limit runtime by using a battery that won't allow long enough run time to cause the heat buildup in the body to become an issue?"

The problem was, that cell didn't really exist at the time I began all the MULE prototype work. A sized cells, or either 4/5A or 5/4A cells, were the smallest true high current cells available. In the meantime, though, some new cells had become available, and I had heard of them, but didn't have any experience with them yet.

And then Jim dropped the real bomb, "Why don't you build the light in a 2D Mag body?" I asked him how that would be possible and he said, "Use 11 CBP 1650 AA cells, get rid of the Mag switch core, and use a high current rocker switch like Wilkey did in the Aurora." 

Eureka, the game was back on!!! 

Jim volunteered to build the packs, and even design a dedicated charger if I would come up with the rest of the package. He also felt that the ring potting scheme he had employed so successfully in the TigerLight mods might be an answer here as well. He even knew of a rocker switch that might work, and found it.

The project was back on, and not just an Aurora clone, or something in a bigger body, but a completely re-engineered and re-thought light. 

3000 plus lumens in a 2D sized light! A handheld sun!

Now we are 60 days later and the light is close to manufacture. The bugs are mostly worked out, at least the ones Jim and I can find, and now Modamag is working on the ones he can find!

In 2-3 weeks the field testers will have their say, and them we'll go to work to hammer these out and get them out to all the people anxiously awaiting them. 

The ring potting scheme has been abandoned, in favor of a sliding can socket mount, but otherwise the USL is near fruition. 

The remaining bugs with the charging system components will be worked out shortly, since we abandoned the dedicated charger idea for a time tried and proven design, but still have to find power supplies for all the worlds divergent power systems. 

A larger 3" head which would allow the use of some different bulbs, is being studied by Otokoyama, and may be available at a later date.

End of Part 2

Part 3 "Why did Bill choose these parts?" this weekend!

Bill


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## KevinL (Feb 26, 2005)

*Re: Construction secrets of the USL: why it\'s so g*

Coming soon: 

"Secrets of the USL - The Definitive Coffee Table Edition", B.Waites, W.Wong, J.Sexton, Et.Al


Seriously that was an awesome read! I've been amazed by the Aurora since I first started showing up around here but never really imagined it would be even possible for me to own one of those fantastic lights. The amount of engineering that has gone into the USL is simply incredible and not something I'd try to duplicate. My initial guess was that the USL used 2/3A GP high rate NiMH cells, but that was just a wild guess and it was off. 

More than that, it's a worthy challenger to the Surefire Beast in terms of output, formfactor AND rarity - only 85 available for civilian sale, well, the USL - only 60 available for CPF-only sale.... /ubbthreads/images/graemlins/grin.gif

It will truly be an honor to be the custodian of such an incredible light. Something tells me I made the right call to 'just buy it' /ubbthreads/images/graemlins/grin.gif


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## bwaites (Feb 26, 2005)

*Re: Construction secrets of the USL: why it\'s so g*

KevinL, 

Just wait for the pictures, a good coffee table book has to have pictures!! /ubbthreads/images/graemlins/hahaha.gif

As I have worked on the USL, I have been amazed that so many people have contributed in so many ways. Many haven't done it directly on the USL, but have helped with other of my projects, simplifying them so I could concentrate on the vagaries of the USL or have offered to assist in other ways so I could financially keep the ball rolling on the USL.

No one has said, "I'm not going to help", "You're nuts, figure it out yourself" or really anything negative at all. 

Many people, including KevinL, JS Burley, Cue003, and others have extended a hand just for my asking and have helped either with direct help or with allowing me materials to complete other projects while working on the USL. 

Thanks to all of you, both the named and unnamed!!

Bill


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## vacuum3d (Feb 26, 2005)

*Re: Construction secrets of the USL: why it\'s so g*

This is fascinating read. I've been taking notes as I read /ubbthreads/images/graemlins/smile.gif

ernest


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## Ginseng (Feb 26, 2005)

*Re: Construction secrets of the USL: why it\'s so g*

Wow,

This provides me with a lot more perspective than I had previously. Excellent writeup Bill. Thanks for sharing your trials and trevails. We remain behind you in support of this project which has become truly your own, unique contribution to the knowledge base. I'm not shining you on when I say you've made your place in CPF history.

Keep it rocking!

Wilkey


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## bwaites (Feb 26, 2005)

*Re: Construction secrets of the USL: why it\'s so g*

Part 3 or "Why did Bill choose THESE parts?"

After several episodes of engineering and then re-engineering the MULE body and it's variations, I was excited that a stock MagLite body might be used as the basis for the USL.

For those of you who haven't designed a flashlight body and tried to have it manufactured, or at least those of you who aren't product development engineers, it is a nightmare of one problem after another! 

Just a few: What kind of threading, metric or standard, do you need Orings, where do the Orings go, what are the Oring tolerances, what are the Orings made of? How fine a pitch for the threads, inside or outside tailcap, standard or reverse threads, backwards compatible with a Mag? And so on and so on, ad infinitum!

People criticize Maglite for not changing their products, but after my experience, I am amazed at how well they did it in the first place, because after all these years, their product still works and has had only minimal production driven changes. That is more a testament to their front end engineering than anything else, in my view. As my southern born and bred father taught me, "If it ain't broke son, why are you trying to fix it?"

The 2D MagLite body is perhaps, along with the 3D body, the most widely sold and used light in history. Ask most people today what a flashlight looks like, and they describe a Maglite, and generally a BLACK Maglite! Older people will remember the chrome Ray-o-Vacs, but for the last decade, at least, a flashlight has become almost synonomous with a MagLite. 

The 2D, with a switch almost the same size as a D cell, is a well proportioned light, but that large switch body takes up lots of "engine" room, and if we wanted to install a "Big Block" light engine, it had to go. 

Once the 2D was decided on, and the switch discarded, and since we had already settled on the high current CBP AA's, we had to make sure they fit. Initially, we thought that the CBP's might just fit, since only the fat body, longer run time 2200-2500 AA's seemed to have a problem in the 4AA square configuarations. But the 1650 is a HIGH CURRENT AA and they are also a little fat. A very slight boring of the body, to the level of the threads, but not affecting them, allows a 4 square configuration. 

So now we had the body and the engine. But how would we handle the power that the "big block" could put out? The Mag Switch, which uses the entire Mag body as the return path, functions reasonably well, and in fact, I had done extensive testing with it in the MULE prototypes and found that it was capable of handling the current of the high power lights, albeit at some loss due to resistance. Since it would no longer fit with the high current 11 pack of cells, though, we needed a high current, stout switch. There were 2 options. The Cherry manufactured switch used by Wilkey in the Aurora and a similar switch that Jim Sexton had located. There was no real advantage of one over the other except that the switch Jim found does have a water resistant boot which may be optional. The "ignition" switch discovered by Jim is a very nice unit rated at 16A at 125 volts. It has a very positive engagement, smooths out even more as it is used, and fits very nicely in a modified Mag body tube. For those concerned with the "square peg/round hole" look of the prototype, I believe that we have resolved that issue at this point and will have a field test unit with the new look available in the next week or so!

With the body, engine, and switch found, the development of the actual lamp portion of the light was next!

It will be covered in Part 4 or "We have light and ************ is it bright!"

Bill


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## bwaites (Feb 26, 2005)

*Re: Construction secrets of the USL: why it\'s so g*

Part 4 or "We have light and ************ is it bright!"

With the Body, engine, and ignition path configured, we now had to deal with the lamp/mounting portion of the light.

Wilkey (Ginseng) once again proved himself a true gentleman and stepped up to help with the choice of lamps through his in depth research. The lamps, chosen after extensive testing by Wilkey in the Aurora, and then by myself in the MULE prototypes, are high output specialty lamps produced by Osram of Germany. There is a wide selection of 12 volt lamps, of both transverse and axial filament designs that come in bipin and other configurations available from Osram and some may wish to experiment, especially with the 3 inch head.

The lamp chosen for the USL is a true 12 volt lamp which is very white at 12 volts and tolerates minimal overdrive. However, it is robust at 12 volts and I have managed to pop one only by overdriving. I have 3 lamps with more than 20 hours on each, (that's tough to do when you have only 12-20 minutes of run time on a battery pack, by the way! I connected 2 of them to a power supply and cheated a little!). I have had NO lamp failures under normal use, so I suspect that these lamps will last years under the type of use the USL will get. (Each USL will come with 2 bulbs, however.) This lamp produces 3-4000 lumens at 12 volts and is VERY slightly overdriven, so expect brightness beyond anything you have experienced in a light this size!

It is bright beyond bright, and the axial filament gives a beautiful round hot spot. Depending on which reflector is used, it has some smooth circular ringing, but it is noticable in the white wall test, but not outside.

Initially Jim and I thought that ring potting the lamps, using his ring potting scheme from the Tiger Light on a grander scale, and then placing them into customized Carley reflectors at the point of best focus would work the best. 

After further testing once I had the prototype USL, though, I decided that the mounting system used in the MULE protos was simpler and more cost and time efficient. One of the recent changes which has slowed the pricing involves that adjustment. 

The socket used is a high output 240 volt/20 amp ceramic socket capable of enduring the incredible heat manufactured by these lamps. It is mounted to an aluminum heat sink, mounted within the neck of the body, and will be connected thermally to the body with thermal grease.

The final pieces then are the custom ordered and designed Carley reflectors, and the heat resistant lenses from Flashlightlens.com. The Carley's will be custom ordered with appropriate neck sizing to allow passage of the stock bulb, but may have to be opened up a little if another optional bulb is used. 

I do have concerns about Carley being able to deliver on time, and so the first parts ordered will be the Carleys and the batteries, which must arrive by surface ship from the Far East. 

So there it is, the history and trials of the USL!!

Bill


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## Ginseng (Feb 26, 2005)

*Re: Construction secrets of the USL: why it\'s so g*

Wow!

Wilkey


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## js (Feb 26, 2005)

*Re: Construction secrets of the USL: why it\'s so g*

Bill,

Just for the record, I instaflashed one of these while testing the proto-type. It was only 15 minutes off the charger, though. /ubbthreads/images/graemlins/icon3.gif


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## aussielextsy (Feb 26, 2005)

*Re: Construction secrets of the USL: why it\'s so g*

Hi

Sorry if my questions seem dumb or lame however you give instructions as to how to use the USL w/ Hitec CG-340 charger. Will this be the same with the upgraded triton charger?

also i do own a SF L7 with the charger it comes with a CN400 Series charger but i dont think i can use this as its desinged for the b90 batterys.


----------



## bwaites (Feb 26, 2005)

*Re: Construction secrets of the USL: why it\'s so g*

The Triton is a little different than the CG-340, but everyone will get very detailed instructions, as we want everyone to be very happy with their purchase.

Jim, I'm surprised to hear that!

As you know, I've actually run them all the way up to 13+ volts and not had an burn victim until I hit significantly over that, but I guess 11 charged 1650 could push over 15 volts instantaneously so it is something that can happen. 

Bill


----------



## BVH (Feb 26, 2005)

*Re: Construction secrets of the USL: why it\'s so g*

Bill and all of the other contributors to this sometimes impatiently anticipated (by me) Mini-Sun, THANK YOU Very Much for taking precious time to give all of us salavators a peek into its history. I REALLY enjoyed reading this thread and I can't wait until I have this "light of wonder" in my hand!


----------



## Ginseng (Feb 27, 2005)

*Re: Construction secrets of the USL: why it\'s so g*

Hi Bill,

I have also blown this bulb on fresh Aurora packs. But only within 30 seconds of coming off charger at a high charge rate so the pack was really hot (meaning high voltage as well as warm in termperature). The voltage spike with true HC cells after a high rate charge is pretty ferocious. However, I've never blown one after a low rate charge, trickle or normal top-off at 100mA. 

Wilkey


----------



## bwaites (Feb 27, 2005)

*Re: Construction secrets of the USL: why it\'s so g*

Jim and Wilkey,

Please remind me to include that as part of the charging instructions when I get closer to sending out the lights.

I HAVE included your posts as part of my file to include with the lights.

Bill


----------



## DaveNagy (Feb 27, 2005)

*Re: Construction secrets of the USL: why it\'s so g*

I read through the Triton docs last night, and yes, the charger is definitely smarter than I am. /ubbthreads/images/graemlins/help.gif I've also been reading various other NiMH charging FAQs. This has served to prepare me to ask the following stupid questions:

The Triton (well, both chargers actually) do "peak sensing", in which they stop charging as soon as they sense when the battery voltage starts to drop. There are some settings on the Triton that influence how this works. There's a sensitivity setting (in milli-volts per cell) that controls how small a voltage decrease will terminate the charging session, and there's a "peak delay" setting which controls the number of minutes that need to elapse before the charger even starts looking for the peak. Do you have any recommendations for these two settings?

Everyone seems to recommend using a temperature probe as either the primary method of sensing a fully charged pack, or as a backup to the peak sensing technique. So, I ordered the probe this morning. /ubbthreads/images/graemlins/smile.gif Do you have any recommendations for what to set the temperature cutoff to? Can the Triton probe even be used with the USL pack, given that the pack is glued into the body? Probe pic here. The big prong is the sensor, the other prong serves as a clamp.

There's also a "maximum charge input" setting that limits how many amp-hours the Triton will attempt to cram into the cells, assuming the peak or temperature limits haven't been reached already. I'm not sure how this should be set. Obviously it depends on how depleted the batteries are when you start charging, but let's assume you ran the USL until it started to dim significantly. The Triton manual states that this setting can be 0mAh to 9900mAh. That seems too low, is this another "per cell" setting? The USL uses 11 1650mAh cells, so the total capacity is approaching 18,000mAh, right? How do we tell the Triton to never exceed that?

On the subject of over-discharging, which we never, never, ever want to do, what's a good ending voltage to shoot for? The rule of thumb is not to let the voltage drop below 0.9V-1.0V per cell? So the pack voltage when "dead" should read something like 10V? 

The Triton can do some sort of fancy-dancy charge/discharge cycling of cells. Is there any reason we'd need or want to do this with the USL pack? To break the cells in, or maybe to test the pack's capacity?

Will you be supplying the wires/plugs that connect the charger to the battery pack?

Wow, that was a lot of questions. Thanks in advance.

-Dave


----------



## js (Feb 27, 2005)

*Re: Construction secrets of the USL: why it\'s so g*

[ QUOTE ]
*DaveNagy said:*
I read through the Triton docs last night, and yes, the charger is definitely smarter than I am. /ubbthreads/images/graemlins/help.gif I've also been reading various other NiMH charging FAQs. This has served to prepare me to ask the following stupid questions:

The Triton (well, both chargers actually) do "peak sensing", in which they stop charging as soon as they sense when the battery voltage starts to drop. There are some settings on the Triton that influence how this works. There's a sensitivity setting (in milli-volts per cell) that controls how small a voltage decrease will terminate the charging session, and there's a "peak delay" setting which controls the number of minutes that need to elapse before the charger even starts looking for the peak. Do you have any recommendations for these two settings?

[/ QUOTE ]

In my opinion setting the peak delay to 6 minutes is good, unless you are recharging an almost full pack (which you CAN do with the Triton, but should NOT do with the Hitec), in which case set it to 1 or 0 minutes. I set the sensitivity to 3 mV, but 5 is also fine. I almost never have the Triton false peak detect, so the more sensitive the setting, the better.

The Triton is different than most smart chargers in that it temporarily stops the charge current in order to measure the battery pack voltage. A succession of these measurements is the best way to determine where the pack is in its state of charge. Most chargers measure the APPLIED voltage needed to maintain the constant charge current. This is why you ARE allowed to change the charge current in mid charge with the Triton, but NOT with the Hitec. Once you set the initial charge current with the 340, make sure that it stays at the same setting. Otherwise you are in danger of false peak detecting, or of not peak detecting at all.

[ QUOTE ]
Everyone seems to recommend using a temperature probe as either the primary method of sensing a fully charged pack, or as a backup to the peak sensing technique. So, I ordered the probe this morning. /ubbthreads/images/graemlins/smile.gif Do you have any recommendations for what to set the temperature cutoff to?

[/ QUOTE ]

It depends on how intimately the probe mates to the pack. If it is great thermal contact, a setting of 120 F is recommended. If it is not in such great contact, I would go less. For the TL packs, there was no way to use it in it's standard configuration. It is meant to fit between two batteries side by side, but on many packs this is not possible. Remove the probes adjustable part and use a rubber band to hold the black section as close and snugly to the pack as possible. I use a setting of 105 F for the TL packs. Do a fast charge and see what the temp is at the end, and make the setting about 5 or 10 F above that, but no higher than 120 F.

[ QUOTE ]
Can the Triton probe even be used with the USL pack, given that the pack is glued into the body? Probe pic here. The big prong is the sensor, the other prong serves as a clamp.

[/ QUOTE ]

Yes. I stuck it in the space between two batteries and the body of the light. It was just long enough.

But in any case, the Triton, with its' more advanced method of charge state detection, will be just fine without a temp probe, although it's a great thing to have. Peace of mind. You know that just in case, your pack will still be protected.

[ QUOTE ]
There's also a "maximum charge input" setting that limits how many amp-hours the Triton will attempt to cram into the cells, assuming the peak or temperature limits haven't been reached already. I'm not sure how this should be set. Obviously it depends on how depleted the batteries are when you start charging, but let's assume you ran the USL until it started to dim significantly. The Triton manual states that this setting can be 0mAh to 9900mAh. That seems too low, is this another "per cell" setting? The USL uses 11 1650mAh cells, so the total capacity is approaching 18,000mAh, right? How do we tell the Triton to never exceed that?

[/ QUOTE ]

Cells in series have the same capacity as a single cell, no matter how many are in series. They simply have a higher *voltage* under charger.

Cells in parallel have a higher (2x or 3x or etc.) capacity and the same voltage as a single cell. Clear?

I would set the maximum charge input to 10 percent over the capacity of a high current cell, give or take. So 1650 + 165 = about 1800 mAh.

[ QUOTE ]
On the subject of over-discharging, which we never, never, ever want to do, what's a good ending voltage to shoot for? The rule of thumb is not to let the voltage drop below 0.9V-1.0V per cell? So the pack voltage when "dead" should read something like 10V? 

[/ QUOTE ]

You'd have to have a voltmeter attached to the pack while using it to know when you've hit 10 volts. I've actually done this using the charging cable (it terminates in banana plugs which will fit into a Fluke DMM, and lots of others probably). But you don't need to get this exact. When the light starts to dim up noticeably, then you're done. You won't miss it as long as you are looking at the beam. No worries.

[ QUOTE ]
The Triton can do some sort of fancy-dancy charge/discharge cycling of cells. Is there any reason we'd need or want to do this with the USL pack? To break the cells in, or maybe to test the pack's capacity?

[/ QUOTE ]

There is no reason to do this. I will be doing all the breaking in and cycling. If you let the light sit around unused for 3 months, then it might be a good idea to do a slow-ish charge, 2 hour discharge, fast charge type of cycle, but it is not necessary. Just a good idea. And the Triton lets you do this safely with its' ending voltage set-point.

[ QUOTE ]
Will you be supplying the wires/plugs that connect the charger to the battery pack?

[/ QUOTE ]

Yes.

[ QUOTE ]
Wow, that was a lot of questions. Thanks in advance.

-Dave 

[/ QUOTE ]

You're welcome, and Bill, feel free to add anything and I hope you don't mind me fielding this one.


----------



## bwaites (Feb 27, 2005)

*Re: Construction secrets of the USL: why it\'s so g*

All wiring to connect power supplies, packs, etc. will be supplied and is one of the reasons I have not yet set pricing as one of the international units doesn't even come with a wall plug!

As for the other questions, they will all be addressed when or before you get the USL!

Have faith, we will not lead you blindly into the dark without a properly charged USL!!

And yes, that fancy-dancy discharge stuff is COOL, and you will want to use it to break in the cells!

Bill


----------



## DaveNagy (Feb 27, 2005)

*Re: Construction secrets of the USL: why it\'s so g*

[ QUOTE ]
*js said:*The Triton is different than most smart chargers in that it temporarily stops the charge current in order to measure the battery pack voltage. A succession of these measurements is the best way to determine where the pack is in its state of charge. Most chargers measure the APPLIED voltage needed to maintain the constant charge current. This is why you ARE allowed to change the charge current in mid charge with the Triton, but NOT with the Hitec. Once you set the initial charge current with the 340, make sure that it stays at the same setting. Otherwise you are in danger of false peak detecting, or of not peak detecting at all.

[/ QUOTE ]

/ubbthreads/images/graemlins/bowdown.gif Wow. Incredible knowledge. How the heck do you know things like that!

BTW, here's a pic that (I believe) illustrates that intermittent voltage sampling thing that the Triton does. (the top graph)

[ QUOTE ]
*js said:*Yes. I stuck <the thermal probe> in the space between two batteries and the body of the light. It was just long enough.

[/ QUOTE ]

Great. That sounds very slick. I couldn't find any pictures of that probe that provided any sense of scale, so I wasn't at all sure whether it could be jammed into the tiny space between two AA cells. Sounds like I won't even need Vasoline. /ubbthreads/images/graemlins/grin.gif

[ QUOTE ]
*js said:*Cells in series have the same capacity as a single cell, no matter how many are in series. They simply have a higher voltage under charger.

[/ QUOTE ]

/ubbthreads/images/graemlins/thinking.gif 

/ubbthreads/images/graemlins/duh2.gif

/ubbthreads/images/graemlins/thinking.gif

OMG, you're right! (Of course.) I was thinking, "One little cell has the same capacity as a whole pack? Inconceivable!"

But I guess current doesn't work like that... Wiring up a bunch of cells in series means lots more volts, and hence lots more watts, but the current, or the "capacity to supply current" stays the same. That's brain twisting, that is.

[ QUOTE ]
*js said:*You'd have to have a voltmeter attached to the pack while using it to know when you've hit 10 volts. I've actually done this using the charging cable (it terminates in banana plugs which will fit into a Fluke DMM, and lots of others probably). But you don't need to get this exact. When the light starts to dim up noticeably, then you're done. You won't miss it as long as you are looking at the beam. No worries.

[/ QUOTE ]

Yeah, I didn't mean I wanted to be able to monitor the voltage in the field, I meant after the fact when I connected the pack to the charger. The Triton displays the pack's voltage in real time, doesn't it? I figured that if I slapped the pack on the charger and it read (say) 11 volts, I'd know that I had left some gas in the tank. But if it read (say) 8 volts, I'd know that I'd screwed up and perhaps hosed my batteries. If, God forbid, I did manage to over-discharge the pack, would I want to do a super slow charge or something to try to bring the cells back from the dead? And if so, what is the "Oh no, now you've done it" voltage? 10V? 9V?

Thanks so much for answering all my questions so quickly and well.

-Dave


----------



## js (Feb 27, 2005)

*re: Battey construction details & History of the U*

Dave,

.4 volts/cell or less on a resting pack almost certainly spells doom, and requires a very slow trickle charge to resussitate, and even that may not salvage things.

But anyway, the thing about high current drains, is that you will hit the rapid dimming phase of the run, turn off, and 30 seconds later, your pack will be approaching 1.1 to 1.2 volts per cell. And you can turn back on for 5 or 10 seconds before hitting dimming again. And then watch the pack recover, and then do it again, and so on. Ginseng covers this pretty well in his "High Current vs. High Capacity" thread.

Anyway, I'd say that once the pack gets to the point where it hits dimming in less than 4 or 5 seconds, you'd better not try to get any more juice out of 'er.

But the good thing about NiMH is that you're free to top off as often as needed, although if you've used less than 10 percent of the capacity, it's probably better to just wait until after more use before topping off. But in any case, trying to decide when your pack is totally used up is not really much of an issue.

And you're not going to over-discharge this pack, because you are *not going to run the light unattented*! That would be the fast road to a visit from the fire department vehicles.


----------



## Codeman (Feb 27, 2005)

*Re: re: Battey construction details & History of the U*

We interrupt this thread to say



WOW!

As a relative newbie to the USL, and a complete hotwire virgin, I am more and more in awe!

JS & bwaites - thank you for taking the time to write all of this up! My USL will definitely be a prized and respected possession after reading this.


----------



## DaveNagy (Feb 27, 2005)

*Re: re: Battey construction details & History of t*

[ QUOTE ]
*js said:* But anyway, the thing about high current drains, is that you will hit the rapid dimming phase of the run, turn off, and 30 seconds later, your pack will be approaching 1.1 to 1.2 volts per cell. And you can turn back on for 5 or 10 seconds before hitting dimming again. And then watch the pack recover, and then do it again, and so on. Ginseng covers this pretty well in his "High Current vs. High Capacity" thread.

[/ QUOTE ]

Here's a link to Ginseng's thread. It appears that "our" batteries are firmly in the high-current camp. /ubbthreads/images/graemlins/smile.gif

-Dave


----------



## Ginseng (Feb 27, 2005)

*Re: re: Battey construction details & History of t*

Dave,

I don't see that. The CBPs are most definitely classed as high-current. I also present curves at two different demands, 4.6 and 8.3 amps. The performance is consistent for the KAN HC cells. 

Did I misunderstand your post?

Wilkey


----------



## DaveNagy (Feb 28, 2005)

*Re: re: Battey construction details & History of t*

Nope, my goof. I was thinking one thing and typed another. Thanks for catching it. Fixed.

-Dave


----------



## bwaites (Feb 28, 2005)

*Re: re: Battey construction details & History of t*

Just as a little aside, the 1650 at 10 amps maintains 1.1 volts for well more than 80% of its capacity and stays above 1 volt for more than 90% of its capacity.

That means that when the USL dims, it does it in a HURRY and needs to be shut down, RIGHT NOW!!

One other quick note from Wilkey's old thread, watch what happens with intermittant use to run time:

Here is some more information. I recently completed tests at a more demanding 8.33 amperes. This would be a 12V/100W bulb. I did this test both continuous and intermittent. The continuous test is self explanatory. The intermittent test was designed to more closely model how a flashaholic might actually play with a torch. The light was on for 30 seconds and then off for 90 seconds in each 2 minute cycle. Note that I did not alter the on-off ratios to determine the resultant effect on capacity. 

I found that if the cells are rested after each discharge, you can squeeze out much more of the capacity. I guess this makes sense. Continuous, high current demand is recognized to dramatically decrease the actual capacity yield. In this case, the continuous draw led to a capacity yield of about 60-65% or about 5 minutes of voltage greater than 12V. The intermittent test yielded 12.23V even after 7 total minutes of on-time. Extending the curves shows that approximately 9 minutes of 12V+ operation could be achieved. This is a substantial, near doubling of the capacity yield. Note that the intervals near the end were extended due to boredom as 123 datapoints were manually collected. Open circuit pack voltage was decreased from the initial 15.20V to 14.28V three hours after the final intermittent discharge.


Bill


----------



## KevinL (Feb 28, 2005)

*Re: re: Battey construction details & History of t*

[ QUOTE ]
*Codeman said:*
We interrupt this thread to say



WOW!

As a relative newbie to the USL, and a complete hotwire virgin, I am more and more in awe!

JS & bwaites - thank you for taking the time to write all of this up! My USL will definitely be a prized and respected possession after reading this. 

[/ QUOTE ]

Hey, did you remember to add the Coffee Table Book and glass USL Trophy Case to my order? /ubbthreads/images/graemlins/grin.gif

I love a light with some history, and this one already has a lifetime's worth - before it even goes into production.


----------



## Dynacolt (Mar 1, 2005)

*Re: re: Battey construction details & History of t*

I think it was Bill who mentioned some time ago that the USL would be packed safely for shipping. I rencently had a light inspected by customs (in Australia, Every item is at least x-rayed). although they didn't touch anything, I'm a little concerned they might wonder what the USL battery pack is, or try to turn it on to see if they really are batteries (and not some other 'stuff' packed into a mag tube /ubbthreads/images/graemlins/ooo.gif).
Will the light be disabled for shipping?
Thanks,
Dave.


----------



## bwaites (Mar 1, 2005)

*Re: re: Battey construction details & History of t*

Yes, it will be disabled.

The bulbs will not be in place. Accidental activation while packed would cause a fire, something the US Postal Service frowns on!

If they take it apart, there will be an instruction manual with it so they could install the bulb and check it. 

Bill


----------



## kevindick (Mar 1, 2005)

*Re: re: Battey construction details & History of t*

I now have a vision of a customs inspector putting together a USL, pointing it at his partner, and saying, "Hey Bob, is this thing on?" The only answer is a scream, followed by a whimper.

So I assume you put a warning along with the manual.


----------



## aussielextsy (Mar 1, 2005)

*Re: re: Battey construction details & History of t*

Hi

Does anyone know when the payment thread is opening up


----------



## bwaites (Mar 1, 2005)

*Re: re: Battey construction details & History of t*

Within 48 hours, I'm waiting on one last, and hopefully the best, bid on the Tritons and for a final cost on the machining changes I made this weekend.

Bill


----------



## js (Mar 1, 2005)

*Re: re: Battey construction details & History of t*

OK everyone,

I had a mental malfunction and when I first posted was thinking that the USL was running at 11 amps, but it just ain't so. It is pulling around 8.3 to 8.5 amps. I re-wrote the initial post to reflect this. Also, for the record, I have not tested these cells at 20 amps continuous, so I removed that claim. That information came from the inital results posted by Mike at CBP on www.rcgroups.com.


----------



## Dynacolt (Mar 2, 2005)

*Re: re: Battey construction details & History of t*

Thanks Bill, I feel better for knowing it won't light in transit: it would be a great pity to ruin the battery pack before it's delivered /ubbthreads/images/graemlins/grin.gif

I remain a little anxious though about anyone touching the light and playing with it, I just really hope customs doesn't decide to check it out. I'm happy to pay internatonal Global Express or any similar postage with tracking so I know it's going to get here and not disappear at some airport customs.
Thanks,

Dave.


----------



## js (Mar 7, 2005)

*Re: re: Battey construction details & History of t*

I will be posting pictures very soon--probably tonight, but if not, then tomorrow.


----------



## Codeman (Mar 7, 2005)

*Re: re: Battey construction details & History of t*

/ubbthreads/images/graemlins/happy14.gif /ubbthreads/images/graemlins/popcorn.gif


----------



## js (Mar 7, 2005)

*Re: Battey construction details & History of t*

And now for some pictures . . . /ubbthreads/images/graemlins/smile.gif

For these cells, as for the KAN cells, I do not remove the shrink wrap because they seat well together with the shrink wrap on. Instead, I leave it on and end-to-end solder the batteries together to form stacks, and then I tape the joints for strength and to prevent any solder or exposed battery contact surface, such as from a nick from the hot soldering iron or from a bit of solder splatter, from contacting any other stack. I also tape the top and bottom of the stacks so that they mate perfectly parallel and even. Below is a picture of soldered and taped battery stacks, ready to be glued and soldered into a USL pack:







And here are the stacks being glued into doublets, the first step of three in the gluing process. Notice that the stacks are resting on a marble slab to ensure they are true and even and level:






Next I mate the proper double stacks into a four stack and using rubber bands and a square I orient them as exactly as possible and run a single RTV glue bead on the top surface (the top and bottom seams are the ones which need gluing at this point, i.e. the double stacks are oriented so that they are on end and not lying down, as in the picture above). When that glue joint dries, I flip the packs over and complete the final step in the gluing process. I then take the completely glued together pack, and solder the three 25 amp tinned copper braid jumpers across the bottom and top of the pack to make all of the electrical connections. Note the kapton tape underneath the edge of the positive battery, beneath the copper braid. This protects against the heat from soldering and from the braid ever making contact with the edge of the negative battery casing which is just below it.






And finally, I run wires from a molex micro-fit connector through the space at the inside of the pack and solder them to the positive and negative terminals of the battery pack. This is the charging connector, and is pictured below. I realize it doesn't look all that appealing, and that the picture quality is poor, but I thought it would be good to show the connector which will be living just underneath the tail cap of the Mag 2D body.






Bill will be making the mainline connections to the switch and lamp when he assembles all of these lights, so I don't show them, nor did I show the pack in a Mag body, because at the moment, I do not have a bored out body into which it will fit.

Thanks everyone!


----------



## tvodrd (Mar 7, 2005)

*Re: Battey construction details & History of t*

Jim,

In the future, don't rule out some long, non-conductive V-blocks from yours truely. Might help(?).

Larry


----------



## DaveNagy (Mar 7, 2005)

*Re: Battey construction details & History of t*

Very nice. How many packs have you finished so far? /ubbthreads/images/graemlins/smile.gif


----------



## nethiker (Mar 7, 2005)

*Re: Battey construction details & History of t*

Awsome pics. Great job keeping us up to date on the project. I'm getting much more than a light out of this. 

Thanks,
Greg


----------



## bwaites (Mar 8, 2005)

*Re: Battey construction details & History of t*

Jim's probably in bed, (At least I hope so!)

He has completed 4 packs, the proof of concept pack in California with Modamag, and the 3 field test packs.

Though just looking at these really doesn't do them justice, Jim does incredibly good work. Anyone who has tried this knows how hard they are to keep square!!!

Bill


----------



## Codeman (Mar 8, 2005)

*Re: Battey construction details & History of t*

Too bad we don't have transparent aluminum, like Scotty in Star Trek!


----------



## js (Mar 8, 2005)

*Re: Battey construction details & History of t*

[ QUOTE ]
*tvodrd said:*

Jim,

In the future, don't rule out some long, non-conductive V-blocks from yours truely. Might help(?).

Larry 


[/ QUOTE ]

Heck yeah! PM sent. I was most definitely planning on making a jig to do this before the massive build runs begin, so if you've got something I can beg, borrow, or steal (or buy) from you, that would be great.

Bill,

So what are you trying to say? That they don't look good in the pictures? /ubbthreads/images/graemlins/evilgrin07.gif /ubbthreads/images/graemlins/icon15.gif


----------



## bwaites (Mar 8, 2005)

*Re: Battey construction details & History of t*

UhOh, 

See what happens when you've been up for 20 hours and type something!!

These are AWESOME Packs!!!!!!!!

Incredibly well built, beautiful, unparalleled in the history of battery pack building.

They could not be built better! (Really, that part, along with all the rest, is true)!

How's that Jim!!

Bill


----------



## js (Mar 8, 2005)

*Re: Battey construction details & History of t*

Bill,

You *know* I was just kidding!!!, and BTW, that was some over the top, rather outrageous flattery! Impressive.


----------



## bwaites (Mar 8, 2005)

*Re: Battey construction details & History of t*

I know, but I really didn't convey how impressive these packs are!

Bill


----------



## Ginseng (Mar 8, 2005)

*Re: Battey construction details & History of t*

Jim,

You might want to look into 90 degree angle stock in aluminum or wood at your local hardware outlet. I use both of these to good effect and no need to jiggle with a square.

Wilkey


----------



## js (Mar 8, 2005)

*Re: Battey construction details & History of t*

Wilkey,

Thanks for the suggestion. We have some of that here in the stock room at work which I can buy in small quantities (at the large quantity discount rate. hehe). In any case, I will set up some kind of a jig for the major build(s). But for three packs, doing things by hand was not that big a deal.


----------



## tvodrd (Mar 8, 2005)

*Re: Battey construction details & History of t*

Jim,

First, condolences on the passing of Hans Bethe. He was a giant!

I was also thinking along wilkey's line. A simple layer of tape could provide insulation if needed.

Larry


----------



## js (Mar 8, 2005)

*Re: Battey construction details & History of t*

Larry,

Thanks. Yes, indeed, Hans Bethe was quite the giant in the scientific community. A general email went out yesterday to everyone in the lab.

And yes, I have some metal angle bracket which I use as my end-to-end soldering jig, to ensure that the batteries are soldered together straight. I just need a larger section for the gluing together of the double stacks. Insulation is not necessary, although it wouldn't be a bad idea. I have kapton tape on my soldering jig, but that is more for when I'm soldering cells with no shrink wrap (such as the GP 1100 2/3A's used in the M6-R packs). In any case, it makes the batteries slide nicely along the jig, though.


----------



## tvodrd (Mar 8, 2005)

*Re: Battey construction details & History of t*

I just checked my garage and I have 4-5' of 2"x2"x1/16" alum. angle. I'd be happy to cut it into ?" long pieces and mail it to you. /ubbthreads/images/graemlins/smile.gif

Larry


----------



## js (Mar 9, 2005)

*Re: Battey construction details & History of t*

Larry,

That would be great. A single one foot long piece will be sufficient. PM sent.


----------



## js (Jan 26, 2006)

*Re: Battey construction details & History of t*

OK. Time to make a post to this thread to bring it up to speed!

Bill and I had problems with leaky cells in the USL battery packs. In fact, out of a run of 23 packs, I think five of them developed leaks in one or more of their cells. Obviously, this is unacceptable, both for the people who had to return their USL's for re-work, and for me and Bill who actually had to do the re-work (LOL) 

Our first thought was that the seals on the cells were failing due to the high current demands and heating during discharging and charging. We suspected this failure mode because I had seen some of the cells, new-in-box, that had leaky seals. And because I had end-to-end soldered many cells before, including other AA's, and never had seen a leaky seal.

So I borrowed two FiveMega 9 AA-to-3 D holders (Bill *may* see them again someday. hehe) from Bill and did "pre"-cycling of a batch of them. "Pre" meaning pre-soldering. Not a single one of them developed a leaking seal, despite a vigorous final charge rate and no small amount of heat and pressure on the cells.

Thus, the finger is vaguely, but definitely, pointed in the direction of the end-to-end soldering being the culprit. So I investigated getting the packs made with welded connections. I worked with a company I have worked with before, and which I trust, and specified double thick and almost tripple wide nickel ribbon connectors, with *four* weld points per contact, and had them make me up two sample packs from CBP1650's. They arrived yesterday and they look very nice:







And here is a closer shot of the end of the pack to show the ribbon connectors and quadruple welded contact points:






Initial testing indicates that the total resistance of the joints in the packs is very low indeed, and so I will be having all the remaining USL packs made by this company.

A plus to this construction method is that the joints are now proof against drops and shocks, and so this will mean a more rugged and reliable USL, although the soldered packs are pretty durable as well. Just not as proof against drops and sharp knocks. Either way, this is bad for the cells themselves and thus should be avoided.

As an end note, I should mention that if you order a welded pack from one of the usual suppliers, you will almost certainly NOT get joints made this way, and they will almost certainly NOT be low enough resistance to carry 8 or 9 amps without significant losses. If you order a welded pack for an Aurora class light, be sure to ask for nickel ribbon which is 10 mils thick instead of 5, and make sure it is at least 1/4" wide and has four weld points per contact (8 per ribbon).


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## Codeman (Jan 26, 2006)

*Re: Battey construction details & History of t*

Glad to see you add this, Jim. If I ever decide to actually get my hands dirty, this would be one of my reference threads. CPF may have "issues" at times, but the community spirit of modding still lives! It's good to be reminded of that.


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## js (Jan 26, 2006)

*Re: Battey construction details & History of t*

Ray,

Yes indeed. The community spirit does still live, and you said it! It is GOOD to be reminded of that, especially of late in my case. Hence the thread house-keeping and updating.

Good to hear from you, Ray. Hope you're keeping wild Bill in line, 'cause I'm not. I may be part of the problem and not the solution. So you'd better be the "good cop" for a while. At least until the USL project sees completion. :devil:


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## Codeman (Jan 26, 2006)

*Re: Battey construction details & History of t*

Well, if Bill's out of yeller grits, I've got some serious leverage that I can apply!

Oh, Bill....


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## js (Nov 3, 2006)

*Re: Battey construction details & History of t*

I was looking through some of my old threads just now and I wanted to do a bit more housekeeping to this one, and bump it up for fun in time for the next batch of USL's that Bill will be making soon.

OK, first, it turned out that the end-to-end soldering WAS NOT the cause of the leaking cells. We had a bunch of welded packs develope leaking cells, just like the ones I hand-soldered.

But the good news is that the latest batch of cells have all been cycled separately, and none of them have leaked. So we will have these made into welded packs very soon. AND, I will be buying more CBP1650's so that we will have enough packs to completely FINISH the USL build.

It's been a long road with many delays--almost all of them due to battery issues. Supply issues, leaky pack issues, and more supply issues. But what can you do? The CBP1650's are the only AA cell that will handle 9 amps--at least right now and for the near term.

OK. So there's the update/bump.


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## paulr (Nov 3, 2006)

Do KAN 1400's not exist any more? These CBP's seem to have been a pretty raw deal.


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## aosty (Nov 3, 2006)

*Re: Battey construction details & History of t*



js said:


> It's been a long road with many delays--almost all of them due to battery issues. Supply issues, leaky pack issues, and more supply issues. But what can you do? The CBP1650's are the only AA cell that will handle 9 amps--at least right now and for the near term.



Have you considered Eneloops? According to Silverfox's testing and my usage with a 64625 light at ~9A, they are quite capable. They also have higher capacity, low self-discharge rate, and no reports of any leaking yet.

http://candlepowerforums.com/vb/showthread.php?t=79302 


Data copied from Silverfox's graphs:


Eneloop:
4.0 A - 1.754 Ah - 1.945 Wh - 26.3 M
6.0 A - 1.753 Ah - 1.937 Wh - 17.5 M
8.0 A - 1.824 Ah - 1.929 Wh - 13.7 M
10.0 A - 1.558 Ah - 1.579 Wh - 9.4 M

CBP1650:
5.0 A - 1.565 Ah - 1.704 Wh - 18.8 M
10.0 A - 1.478 Ah - 1.456 Wh - 8.9 M


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## js (Nov 3, 2006)

*Re: Battey construction details & History of t*

paulr,

KAN1400's exist in the sense that you could maybe find someone to sell you some, but you don't want to buy them even if you could find them. According to Steve at www.battlepack.com, KAN "Lost the formula" and started producing bad cells, and just never recovered from that. Bill and I considered KAN1400 or 1300 when we had all the CBP1650 trouble.

aosty,

Interesting! Yes. I did consider them when they first came out, but in a phone conversation with Tom, I think the verdict was that the voltage under load wasn't good enough.

BUT, looking at those numbers there, the enelope seem to have just as good voltage as the CBP1650's (take Wh and divide by Ah and you get a number which corresponds with voltage mid point). I'm getting some enelopes on Monday. I think I'll have to do some testing.

Thanks!

Still, though, I'm pretty conservative about these things. We know the CBP1650's will hold up to 9 amps over time, and will hold good voltage under load. If the leaking cells are a thing of the past, they are probably still our best bet. I really wouldn't want two or three dozen packs go south after a dozen cycles. Plus, the enelopes have a button top, right? This would make it impossible to do four weld points at the positive contact, making for a higher resistance joint, making for a higher resistance pack. Or at least that's what I think would be the case. I'll defintely be looking into it, though. Thanks!


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