# P91 on AW 17500 Protected cells?



## jtivat (Jul 1, 2010)

Is it safe to run the P91 on these cells?

Thanks
JT


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## ninemm (Jul 1, 2010)

Hmm. Well I will tenatively say yes w/reservations based on some other threads I have read. Running a P91 on 2 li-ions will decrease the bulb life and maybe run the risk of a  

But someone else with more experience should be able to chime in with a definitive answer.


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## fivemega (Jul 1, 2010)

jtivat said:


> Is it safe to run the P91 on these cells?
> 
> Thanks
> JT



*Current draw of P91 is higher than 2C of 17500 and NOT RECOMMENDED*.


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## DUQ (Jul 1, 2010)

P90 = Yes 

P91 = No!


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## ninemm (Jul 1, 2010)

fivemega said:


> *Current draw of P91 is higher than 2C of 17500 and NOT RECOMMENDED*.


 


DUQ said:


> P90 = Yes
> 
> P91 = No!


 
Those were the definitive answers I was sure would come up. Thanks for chiming in guys.


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## matt_o (Jul 2, 2010)

I have gray UltraFires that are rated at 1300mAh. I just checked and my P91 pulls 2.5 amps with them. This puts it just under 2C. The AW's are rated at 1100mAh which puts them over 2C. Are my UltraFires okay to use?


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## Kestrel (Jul 2, 2010)

matt_o said:


> I have gray UltraFires that are rated at 1300mAh. I just checked and my P91 pulls 2.5 amps with them. This puts it just under 2C. The AW's are rated at 1100mAh which puts them over 2C. Are my UltraFires okay to use?


How about if I mark out the '1100 mAh' on my AW 17500's and write in '1400 mAh' instead?


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## nzgunnie (Jul 2, 2010)

matt_o said:


> I have gray UltraFires that are rated at 1300mAh. I just checked and my P91 pulls 2.5 amps with them. This puts it just under 2C. The AW's are rated at 1100mAh which puts them over 2C. Are my UltraFires okay to use?



The label on your batteries says 1300 mAh - are they actually 1300 mAh? Unlikely, especially under load.


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## Brigadier (Jul 2, 2010)

I wouldn't risk it. And I wish AW would make IMR17500's. :thumbsup:


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## fivemega (Jul 2, 2010)

Brigadier said:


> I wouldn't risk it. And I wish AW would make IMR17500's. :thumbsup:


*P91 is severely overdriven with 2 Li-Cobalt cells.
Even if we see IMR 17500 in future, chance of instaflashling will be greather and poof of $30 bulb is painfull and not reliable.
I highly recommend WA1111 in Sunlight power up with 2 protected 18650 or 2 protected 18500 with 1794*


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## Brigadier (Jul 2, 2010)

fivemega said:


> *P91 is severely overdriven with 2 Li-Cobalt cells.*
> *Even if we see IMR 17500 in future, chance of instaflashling will be greather and poof of $30 bulb is painfull and not reliable.*
> *I highly recommend WA1111 in Sunlight power up with 2 protected 18650 or 2 protected 18500 with 1794*


 
So, in a stock 9P/G3, if you want to run the P91, it is primaries only?


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## jtivat (Jul 2, 2010)

So are we talking a danger of wrecking the batteries or the batteries going boom?


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## fivemega (Jul 2, 2010)

Brigadier said:


> So, in a stock 9P/G3, if you want to run the P91, it is primaries only?



*Many people overload their Li-Cobalt batteries to over 2.5C at their own risk. It's not safe and I won't recommend it. 
However, It's your choice.
If you really want to use P91 in 9P size, at least have it bored out and use pair of protected 18500*
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jtivat said:


> So are we talking a danger of wrecking the batteries or the batteries going boom?


*Both.*


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## nfetterly (Jul 2, 2010)

I run P91 on 2 IMR16340s - but I also use a AW 3 level soft start. VERY NICE.

I also suggest posting a WTB on P91s - I picked them up for as little as 2 for $15 and as much as 1 for $15.

I also do *very very* highly recommend the FM/Carley 1794 that Nite is selling for use in FMs holder. I've got ~15 of these bulbs. Incredible.


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## nfetterly (Jul 2, 2010)

Sorry, double post...


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## jtivat (Jul 2, 2010)

What about these? 
AW 17670/1600 Lithium Cobalt (LiIon)

They claim they are good to 5 amps.

Thanks
JT


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## fivemega (Jul 2, 2010)

jtivat said:


> What about these?
> AW 17670/1600 Lithium Cobalt (LiIon)
> 
> They claim they are good to 5 amps.
> ...



*9P with a cell extender and pair of protected 17670 will overdrive P91 but safe for batteries.
5 Amps claim is for LEDs which do not have initial spike.
Pair of AW's new protected 17670 cells won't power up a ROP 3854 Hi bulb (single click) which needs about 4.4 Amps but initial spike is way higher than 5 amps.*


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## 325addict (Jul 4, 2010)

I measured capacity of the gray UltraFire 17500 cells: it is around 1075mAh (which is not bad, an AW hardly has more capacity).
The difference is the quality of the cell. While the AW cells retain their voltage very well, the UF cells will go down to as low as 4.04V within 24 hours, while the AW cells will still retain around 4.17V after that time.

If you want a BRIGHT and safe-to-use incan of this size, you just NEED that G4 Sunlight D26 module Fivemega sells!! Indeed, put in a WA1111 or WA1274 (2-cell application) or a WA1166 or WA1185 (three cell application) and you're DONE

I use AW 16340 IMR cells for this purpose. Short run times, but oh so much FUN :thumbsup:


Timmo.


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## ampdude (Jul 5, 2010)

You could try a pair of AW's IMR14500 cells with some 14mm pvc pipe to keep it from rattling in your three cell light. I sure wish IMR17500's were available for us three cell Surefire users. And some IMR17670's for the two cell Surefire users.


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## ampdude (Jul 5, 2010)

325addict said:


> I measured capacity of the gray UltraFire 17500 cells: it is around 1075mAh (which is not bad, an AW hardly has more capacity).
> The difference is the quality of the cell. While the AW cells retain their voltage very well, the UF cells will go down to as low as 4.04V within 24 hours, while the AW cells will still retain around 4.17V after that time.




I never had that happen with the Ultrafire Gray cells, but I did get a bad cell in the first batch and I've never had a bad AW cell. Sounds like the UF cells you are referring to are bad cells. I had a Pila cell that would lose its voltage below 4V after about a week or so. That's not normal behavior for lithium ion. Either bad cell or bad protection circuit I imagine.


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## ampdude (Jul 5, 2010)

fivemega said:


> *P91 is severely overdriven with 2 Li-Cobalt cells.
> Even if we see IMR 17500 in future, chance of instaflashling will be greather and poof of $30 bulb is painfull and not reliable.
> I highly recommend WA1111 in Sunlight power up with 2 protected 18650 or 2 protected 18500 with 1794*



I've used the P91 quite a bit with IMR18500 cells and found that particular combo to be reliable, so I wouldn't hesitate to do the IMR17500 thing, however we all know of course the P91 is a bit of a touchy bulb and the end user's mileage may vary! :thumbsup:


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## zygibajt (Jul 7, 2010)

Well I wouldn't call P91 touchy. In fact I found all of the D26 drop-ins bulbs somehow more bumb proof than turbohead bulbs. I have overdriven P61, P90, and P91 and they all seems to take it more easily than turbohead's MN15, M20 and MN16 without even getti ng a little bit dark. Only P60 was quite sensitive.

But this does not change the fact that P91 is hardly (HARDLY) overdriven with eiather of 3,7 V Li-ion cells. Just check how much more output in lumens they produce compared to driven with primaries. It just proves how bumb proof they are to survive any time at all.






ampdude said:


> I've used the P91 quite a bit with IMR18500 cells and found that particular combo to be reliable, so I wouldn't hesitate to do the IMR17500 thing, however we all know of course the P91 is a bit of a touchy bulb and the end user's mileage may vary! :thumbsup:


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## computernut (Jul 7, 2010)

I believe the issue is the P91 draws too much current for the LiCo 17500's, something like 2.7amps.


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## Chrontius (Jul 7, 2010)

nfetterly said:


> I run P91 on 2 IMR16340s - but I also use a AW 3 level soft start. VERY NICE.
> 
> I also suggest posting a WTB on P91s - I picked them up for as little as 2 for $15 and as much as 1 for $15.
> 
> I also do *very very* highly recommend the FM/Carley 1794 that Nite is selling for use in FMs holder. I've got ~15 of these bulbs. Incredible.



I second the P91/IMR combination. I have one on my hip right now in a G2Z, without the softstart. A little riskier, but I've yet to have any trouble with it, and it produces 420 lumens (per our benchmark thread) in this configuration, at peak. As a short-run emergency/tactical light, with correspondingly few cycles on the bulb (but always enough to test for infant mortality!) it's an excellent choice.

I've yet to experiment with the 1794, but that's likely my next project (in a MiniMag, no less!)


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