Surefire KT1 or KT2? Advice please :)

[Niconical]

Hello.

Firstly, I'm sorry if this question is obvious.
I'm (reasonably) sure of the answer, but I want to check before parting with a good load of cash.

As far as I know it, the KT1 is a turbohead and 6v lamp, to be fitted to the matching 6v Surefire lights, 6P, C2 etc. The KT2 is the 9v equivalent, turbohead plus 9v lamp for use with the 9P, C3 etc.

My question is this. If I intend to use 2 x IMR16340 batteries, can I just get a KT2 but put it on a 6P type light? Does the KT2, meant for 9v lights, actually connect to the 6v sized lights? I'm sure after that there will also be more lamp options, but for now I just want to confirm that the KT2 fits on the 6P, and that 2 x IMR16340 will power the lamp that comes with it, to get me started.

I would assume it does, not from knowledge or experience, just from the fact that everything else for those lights seems to be lego-able.

Any advice Would be appreciated.

Thank you

 

[Flash_Gordon]

The KT1 and KT2 are identical except for the voltage of the lamp assembly originally included.

The IMR16340 cells will charge up to about 4.2V. Too much for a 6V LA at around 8V. Not enough for a 9V LA.

Mark

 

[nzgunnie]

The KT1 and KT2 are identical except for the voltage of the lamp assembly originally included.

The IMR16340 cells will charge up to about 4.2V. Too much for a 6V LA at around 8V. Not enough for a 9V LA.

Mark

Well you score 50%.

They are identical, they just ship with different lamps.

That setup will work fine, albeit with quite short run time, dependant on what 9V lamp you are wanting to use. 9V lamps are only nominally 9V as the manufacturers design in the voltage drop that the '9V' cells will suffer under the current load imposed on them by the bulb. As you can see from the link I've posted below, two 4.2-3.7v bulbs will often provide more voltage to the lamp than 3xCR123s will, depending on the current draw of the lamp.

If you are only wanting to use the MN15 (that comes with the KT-2), you would be better getting AWs protected RCR123 cells as these have a higher capacity than the new IMR16340 cells, but can still handle the current of the MN15 (or N2 if your KT-2 turns up with that). The MN15 draws about 1.2a. If you want to go to a lamp with a higher current draw, you will need to use IMR16340 cells, which AW suggests perform bests at current above 1.5a.

This thread:
http://candlepowerforums.com/vb/showthread.php?t=161536

will answer quite a few questions.

Another thing to consider is that the advantage of the 6P over the 9P is it's ease of carry. As soon as you put a KT-2 on it you loose that. Unless the length is critical, you are far better served by getting a 9P (or even a leef body) and usung the KT-2 on the 9P and using 17500s (or even better 18500s in the leef). This will allow a far more useful run time with the MN15, and even allow you to go to the Lumens Factory EO-M3T. If you went for the leef body and decided to run 18500s, you could run the MN16, and of course the MN15 would have even longer run time again.

 

[Niconical]

Thanks for the replies

The reason I decided on the KT2, with the 9v lamp, but used on a 6P, is because I have 6 of the IMR16340 on the way to me, but no specific use for them. Ideally I'd love to put the KT2 on a 9P (I have one available), but then 3 x IMR16340 would surely fry the supplied 9v lamp.

If the turboheads are the same, I'll go for the KT2, use it on a 6P for now, giving me a lamp to get me started (the one that comes with the KT2), and a use for the IMR16340. Then when I have some more cash I'll look into other battery/lamp options to use the KT2 with a 9P.

Well, that's the plan anyway, but if there's anything wrong with it, please let me know.

Actually, one final thought, is there possibly a lamp to go in the KT2, and be run with 3 x IMR16340 in the 9P?
I don't think so, but it doesn't hurt to ask I suppose.

 

[socom1970]

...is there possibly a lamp to go in the KT2, and be run with 3 x IMR16340 in the 9P?
I don't think so, but it doesn't hurt to ask I suppose.

You could use the SF MN60 lamp assy. that is used in the SF M4 for your 9P. The three cells together would put out approx. 12.6 volts. The MN60 is about a 13v lamp. I don't know the max. safe current draw on your cells, but you should be fine with the MN60 (225 lumens).

You could also use the MN61 LA (325 lumens) at reduced run time if your cells are able to handle the current draw, but don't do that unless you DEFINITELY know the max current draw of the cells as well as the draw of the MN61. Any of the SF extreme output lamps draw a LOT of current which can be catastrophically bad if used with cells that can't handle those current-hungry lamps.

You might also try the Lumens Factory lamps for the SF M4. From what I've seen with my LF lamps, they seem to be a bit more efficient and draw a bit less current. I don't know the part numbers offhand, but they are easy to find on lighthound.com, which is where I got mine from. I really like the LF lamps and you might also.:thumbsup:

 

[Chongker]

Niconical,

Answered your question about what i'm running on my 6PKT1 but though I might as well post some info here as well.


The KT1 and 2 are exactly the same except for their lamp assemblies. The KT1 comes with and N1 designed to work with 2 primaries, while the KT2 comes with the MN15, designed to work with 3 primaries. Why the MN15 is called a 9V lamp is so that your average joe can use basic maths and add up the numbers on all the cells, 3V+3V+3V=9V. But primary CR123a's don't actually work at 3V, the thread linked above will explain nicely. The MN 15 is actually a ~7.4V lamp so that it can run one the nominal voltage provided by the primary cells, roughly 2.4v ea.

Li-ion cells, especially IMR cells, hold their charge much better, and despite being rated 4.2V, the usually hold 3.6-3.7V on a load. This gives the lamp slightly higher V than regular primaries, and 2 of them can run a '9V' lamp as long as they can take the current.

So that's basically a short summary of MD's guide.

As to what bulb to run on 3 IMR16340's, the MN61 could work, the cells would be able to take the current quite well I think, though the bulb will be VERY overdriven, and have a short life. Getting a WA1185 to run in the turbohead would be much more interesting IMO, and cheaper per bulb too.

 

[nzgunnie]

Ideally I'd love to put the KT2 on a 9P (I have one available), but then 3 x IMR16340 would surely fry the supplied 9v lamp.

Yes it would. You would been 2x17500 cells.