IMR 17670

[Chrontius]

I'll be blunt. I've been holding off on buying some really fun stuff for want of IMRs that'll fit an E-body.

Does such a beast exist?

Anybody else want them?

If they dont, and people do, will someone make them?

 

[Point Source]

Are you thinking LF IMR-E1R in an E2E?

Yep, I'd be interested.

 

[Hack On Wheels]

I'm going to assume this wouldn't be for an incandescent setup?

Would this be for an MC-E/P7/SST-50? If I'm not mistaken, the protected 17670 cells are good for up to 2C, and with ~1500mA capacity they will hold up well for a 3A discharge, which is probably more than you would want to run an emitter at in a small host anyways.

If this is for a different application though, I'd certainly be interested to hear about it.

Are you thinking LF IMR-E1R in an E2E?

Yep, I'd be interested.

First I've heard of an IMR-E1(R). I doubt you could get a high enough current draw from ~3.7V to need an IMR17670, let alone an IMR16340.

 

[Chrontius]

Point source, that's one of my options. I was actually leaning strion (for the moment), but EO-E1 is on the table, too.

Hack, I intend to use it on a monster LED more often than an incan, but I find that IMRs don't sag until the very end, and can actually have higher (effective) capacity than LiCo because they don't suffer under load. LiCo's real capacity under heavy drain can fall below that of an equivalent IMR.

Also, I use a good charger, not a hobby-grade one, and feel safer around IMRs. Not only that, you can charge them at 8-10C. Five hours to charge, and you can't safely do it overnight? Feh, my RCRs charge in 20 minutes, tops.

I think safety and fast charging are the more important factors, honestly.

That and the M6-WA1185 rigs people are running on LiCo strike me as pushing it.

Edit: Do they make an IMR-E1? could they?

 

[mdocod]

Do they make an IMR-E1?

Nope

could they?

Not really.

As many people are discovering with direct drive LEDs that are pushing high current (like the SST-90s and stuff), it's often very difficult to get the resistance in the system low enough to achieve the desired drive levels.

As it stands right now, as you may already know, about the highest current 3.7V bulbs available are around 2.4 amps. In order for that to work, the total resistance in the circuit has to be like 1.5 ohm, in terms of resistance, 1.5 ohm is pretty low.

The logical step for a 3.7V bulb to be called an "IMR" bulb would be at least 3 amps. Maybe more. The total resistance in the circuit would have to be down close to an ohm. This gets tricky, and the performance from one unit to the next with mild differences in oxidation on contacts, or even what type of switch is used will start to make noticable differences in output (we see this happening with folks doing the SST-90 DD builds). The tolerance for the filament would start to get really tight and hard to keep consistant from one unit to the next. You'd almost have a Vf variation similar to that of LEDs, which would make things even worse.

Now, consider the following: Designing a high voltage, low current bulb, you use very a very thin long strand of tungsten. The long thin strand has lots of surface area and is wound in such a way where much of the surface area is visible from many possible angles of view, meaning that there are less places where the windings of the filament are blocking light from other parts of the winding. In a low voltage, high current design, the length of the strand gets much shorter, and it must be slightly thicker. The surface area of the filament becomes much smaller, and the thicker filament windings block more light from other parts of the filament.

The result, is that, low voltage high current bulbs suffer from a dramatic hit in efficiency that makes the practicality argument even worse than it already is for incans.

Low voltage low current bulbs can be reasonably efficient, but from the math I have done on bulbs, seems like efficiency really starts to platoe around 12V for most common wattage's.

Hope that helps,

Eric

 

[Hack On Wheels]

Point source, that's one of my options. I was actually leaning strion (for the moment), but EO-E1 is on the table, too.

Hack, I intend to use it on a monster LED more often than an incan, but I find that IMRs don't sag until the very end, and can actually have higher (effective) capacity than LiCo because they don't suffer under load. LiCo's real capacity under heavy drain can fall below that of an equivalent IMR.

Also, I use a good charger, not a hobby-grade one, and feel safer around IMRs. Not only that, you can charge them at 8-10C. Five hours to charge, and you can't safely do it overnight? Feh, my RCRs charge in 20 minutes, tops.

I think safety and fast charging are the more important factors, honestly.

That and the M6-WA1185 rigs people are running on LiCo strike me as pushing it.

Edit: Do they make an IMR-E1? could they?

That makes sense then.

FWIW, I've enjoyed running a Strion bulb from a protected 17670. No experience with the EO-E1R (or however the name goes) though.

Fast charging would be nice touch; you're re-kindling my interest in hobby chargers...

Good point about setups like the 3*17670 in an M6, I forget about some of these potential configurations, and that certainly seems like it would be on the high side for current draw (unless the cells just sag so much that the current draw drops enough and then IMRs would make even more sense) and output must suffer for it.

 

[Point Source]

Sorry for the confusion, guys. The mention of "E series" lead me in the direction of incandescent only, for some reason.

No, the IMR-E1R does not exist, but the HO-E1R and EO-E1R do. So the next logical step (although perhaps impossible/impractical) would be the IMR-E1R in the Lumens Factory naming scheme.

...but it would require an IMR 17670, of course.

So to reiterate, the IMR-E1R idea was born of pure fantasy, not practicality.

But if it did exist, I'd buy a few. :twothumbs

 

[Chrontius]

Mdocod provides a good argument against the IMR-E1, but I maintain that the IMR 17670 is a good idea based on the prevalence of roomsweeper style builds in the last year, M6 hotwires, and charging safety and speed.

We'll just need higher-current cradle chargers to keep up with them. And while that has its own set of risks, it makes it much more likely that the entire charge will be supervised.

 

[bullettproof]

Someone needs to make an IMR 17670. It would be good for the above listed lights.However it would be very useful for guys that don't want to bore there SF host and run an SST50 with out lots of sag.

 

[recDNA]

Someone needs to make an IMR 17670. It would be good for the above listed lights.However it would be very useful for guys that don't want to bore there SF host and run an SST50 with out lots of sag.

+1

 

[Raoul_Duke]

I'd like to see some of these also!...What type of current draw and capacity do we think, in theory, a IMR 17650 would have.

 

[ampdude]

I am more interested in IMR17500 cells, but I also would get some IMR17670 cells for various things.

 

[Chrontius]

Bah, still waiting for those 17670s.

 

[Black Rose]

With the number of unbored 6P and G2 lights out there, you'd think there would be a market for IMR 17670 cells.

 

[Chrontius]

Bought most of the really fun stuff, but I still can't turn it on...

C'mon, IMRs have more capacity than LiCo at over an amp.

 

[ampdude]

It sounds like IMR17500's are going to be a reality for our Surefires.

IMR17670's can't be far behind. I've got a 4 cell E-series body (Balrog) just begging for two of those, a TnC finned E to C adapter, one of Lumens Factory's SRTH Turboheads when they become available and some serious xenon bulbs and maybe even a high power emitter. An E2DL, not to mention a hundred other E-series sized lights could sure benefit from one of those 17670 sized red colored cells too

As we know some of the higher powered LEDs are starting to get monstrous in their current demand and the lithium cobalt cells have their limitations so this is a big plus for both the LED and incan users.

Hopefully we're all a bit of both!

 

[Chrontius]

Sounds like they're going to be a reality?

Do tell!

 

[Brigadier]

It sounds like IMR17500's are going to be a reality for our Surefires.

 

[tygger]

It sounds like IMR17500's are going to be a reality for our Surefires.

IMR17670's can't be far behind.

Are you referring to tactical hid's comment in the Redilast marketplace thread? He said he plans to introduce two sizes of IMR soon but didn't say which ones. Do you have more info?