TigerLight battery construction

[js]

I did a little detective work on my TL battery tonight. I wanted to see if I could determine the cell type without having to unshrink wrap it or disassemble it. A little geometrical calculations of three touching spheres whose centers make an equilateral triangle led me from a height of 30mm to a diameter of 17mm. The length of the cell was visible through the shrink wrap: 43 mm. This leaves only one choice: 4/5 A. Thus the pack is 3 stacks of 2 4/5 A's in triangle formation. Also, for those of you who don't know, the connector for the battery pack is a standard 9 volt battery connection, gold plated, and the cells are NiMH. The pack measures 8.4 volts right off the charger (6 x 1.4) and very quickly (within seconds) hits 7.0-7.1 volts under load (6 x 1.17).

The next step will be to unshrink wrap it to see if the cells are marked so that we can find out their mAHr capacity. I will do this at some point but I want to get a hold of some shrink wrap first so I am not left without my TL.

But the exciting thing is that I'm sure that some one or more of the CPFers (*cough* *Ginseng* *cough* /ubbthreads/images/graemlins/bowdown.gif /ubbthreads/images/graemlins/buttrock.gif ) could put together an even better, higher current and/or higher capacity battery pack. And in any case it has GOT to be cheaper to build one from scratch than to pay $50 for the TL version. Who knows, perhaps I'm wrong, but I doubt it.

Ginseng? Any thoughts?

 

[paulr]

Digi-key, Powersource, and possibly CPF's own Batterystation can make up packs for you complete with shrink wrap.

Edit: Batterystation doesn't make custom packs, but can order in some predefined styles. You want style #33 from

http://www.batterystation.com/configurations.htm

which would cost you $27.50 using KAN high-current NiMH 4/5A cells from

http://www.batterystation.com/nicads.htm

I don't know if that's enough savings to really be worth it.

 

[AilSnail]

You have room for a 2x43=86mm long and 17x2.16=36.7mm dia pack then right? Do you want to keep the same voltage and what is the desired amperage draw?

 

[js]

paulr,

Thanks for the info. As for savings, a $20+ savings is certainly "worth it"! How could it not be? But more importantly, it becomes possible, even likely, that with some luck, research, and diligence, you can better the standard pack. As for having Kevin make a pack for me, NO WAY! Why does he get all the fun!?! TINKERING IS FUN!

AilSnail,

Wo there! You're jumping ahead of me. At the moment I haven't thought of changing the configuration of the battery pack, only about making my own replacement. I haven't yet measured what the TL bulb draws for current, but it can't be too much because the thing runs for an hour plus (1.1 hrs to be exact), which indicates a discharge rate of less than 1C. Even supposing TL put 1900 mAH batteries in there, that's a potent, but not overwhelming 1.7 amp current draw with the standard bulb.

 

[FNG]

I would send a new battery pack to whoever will figure this stuff out but I was too late on the TigerLight sale. They sold out before I could order so I got the free leather holster instead. Should be here in a few days. /ubbthreads/images/graemlins/smile.gif

 

[js]

FNG,

Sorry you didn't get the free battery. No need to worry, I'm going to figure this stuff out, taking the shrink wrap off is absolutely no big deal, I just want to have the appropriate replacement wrap on hand. In fact, I think I'll see what's available right now.

 

[AilSnail]

You should get by with high capacity cells then. Haven't found any cheap deals for 4/5 A.
sanyo hr4/5au 2150mah $4.5 a battery station.
kan1800 $2.95
powerstream 4/5A 2ah $158 for hundred

if you can somehow put a longer pack in there you can get
sanyo KR-1700AU-S for $2 at bs, or
HR-AUX 2.7AH for $4

 

[js]

[ QUOTE ]
You should get by with high capacity cells then. . . .

[/ QUOTE ]

Unless I have something else in mind for the front end. /ubbthreads/images/graemlins/smile.gif

hmmm. what? Did someone say something? Move along. Nothing to see here. Move along, now.

 

[Ginseng]

Hi Jim,
Yep. Good ol' 4/5A nimh. IIRC, PaulW did some testing that indicated the draw was about 1.7A. That makes the pack about a 1.9-2.1Ah depending on what you pick as an end voltage. Traditionally, 1V/cell is the cutoff for capacity calculations. At 6V, I imagine the LA would be starting to get noticeably dim. The 2.1Ah Sanyo 4/5AU cells from Batterystation would be a good bet although I'd confirm that they're flat tops. I'd stick with "high capacity" type cells as, frankly, the current draw isn't significant enough to merit the lower capacity, high current cells lke the KAN1800 or Sanyo 4/5AUP. It also looks like you can get generic 4/5A flat tops at any one of a number of outlets for between $2.50-$3.25 for 1800-2100mAh.

Sure, you could get a pack built but I suspect one-offs would cost you. I guess if I were to build these using anything but the best high current cells, I could do it with the connectors and shrink all for about $35. Believe me, once you see what goes into making a 3-on-3 serial pack, you would not begrudge the $5-8 bucks on top of materials. I won't go into detail here, but it's a pain. Not hard, just a pain. And I've got the right size shrink wrap right here.

And Jim, if you want to run the bulb I'm thinking of, you would most definitely need the KAN or AUP cells. 9 amps to glory!

Wilkey

 

[AilSnail]

well now we're talking. What bulb is that?

 

[Ginseng]

Hehe, let's just say that these would be the only bulbs so far that would even begin to tap the potential of the PowerStream battlebot cells.

Wilkey

 

[js]

Wilkey,

9 amps? No synchronicity this time. I was thinking of the WA 1111 pushed. Judging by the 1160 usage and going by filament thickness and by the V vs. t graph of the TL battery under a mild load (1.7 A) I'd have to say that this 6 volt (nominal) bulb will take it. I know you had doubts when you suggested it to me, but I think you're right. And it's already putting out nearly 500 lumens at 6 volts. At 7 volts, 700 lumens here we come. Of course it'll probably be drawing something like 5 amps! But that's still 20 plus minutes of runtime, depending. I also want to try the 1274. Plus, I wanted to get a few 1164's perhaps. That bulb will definitely take a push if the 1111's should blow. But one way or another, I want the TL back on top again! MagCharger? Pah! Too big and clunky and the switch is in the wrong place, and who the &^**^ wants a focusable beam? No. The TL is destined to RULE! Two can play at the old switcheroo lamp game.

So which 9 amp light source were thinking of, Ginseng?

 

[AilSnail]

[ QUOTE ]
Hehe, let's just say that these would be the only bulbs so far that would even begin to tap the potential of the PowerStream battlebot cells.

Wilkey

[/ QUOTE ]

Now, now. That is what my regular AAA's delivers.

 

[Psychomodo]

My Tigerlight FBOP is due to be delivered anytime now. I get the feeling that soon I may be able to make it perform even better! /ubbthreads/images/graemlins/buttrock.gif

The thought of this is putting a big grin on my face. /ubbthreads/images/graemlins/grin.gif

Good luck guys and keep me informed please. /ubbthreads/images/graemlins/thumbsup.gif

 

[The_LED_Museum]

The stock TigerLight bulb draws approximately 1.71 amps, if this helps with the battery selection.

 

[js]

I finally disassembled my TL stock battery pack. First of all, there was no indication of exactly which cell they are using because during manufacture the shrink wrap on the individual cells was taken off, or was never installed, so that each stack of two could be wrapped as a unit.

The stacks of two cells are connected via thin metal strapping which is spot welded to the + teminal, bent up on either side of the battery above it (the - terminal) and spot welded on each side. The stacks are connected via the same strapping, spot welded to the terminals as before and covered in shrink wrap. One stack is + up, the other two are - up, and are arranged so that the + up stack is directly underneath the + terminal of the 9V connector, and one of the - up stacks is underneath the - 9V connector (the larger one). The top of the battery pack has the 9V snap connectors mounted in .062" fiber board. The bottom is covered with the same .062" fiber board. Each stack is glued to the stack next to it with a silicone type glue, and the whole is wrapped with heat shrink wrap.

The spot welds, while small, are solid and good. The metal strapping while relatively thin, is more than sufficient to carry a couple three amps.

I am currently in the process of gearing up to make custom hi-current TL packs with the KAN 1800 4/5A cells. Please see The TigerLight Upgrade Thread for details.

 

[Ginseng]

Sounds like a typical resistance welded pack. Interstate Battery and others use this technique. It is very rugged.

I am anxiously waiting to se ehow the KAN1800s perform in your light.

Wilkey

 

[js]

Wilkey,

What other NiMH cells should I try? Which are the top contenders for my application? I'd even consider getting 100 PowerStream 4/5A NiMH if you thought that they'd be the absolute best.

 

[Ginseng]

Jim,

I don't think the regular TL LA qualifies as a high drain application so you might be able to move to high capacity-type cells instead. The internal impedance is about on par with the Maha AAs so I'd expect similar voltage drop. This means that it'd probably even be suitable for the 3.3A Sl-35X LA. Actually, this looks to be a pretty good choice. I know BatteryStation carries these cells.

Wilkey

 

[S4MadMan]

Jim and Wilkey, whatever you guys have up your sleeve...

...I'm game! /ubbthreads/images/graemlins/grin.gif

Once it's completed, please advise how much to PayPal and I will do it. /ubbthreads/images/graemlins/thumbsup.gif /ubbthreads/images/graemlins/buttrock.gif