# AW 18650 - You decide...and why.



## Ryanrpm (Jan 5, 2009)

*IMR18650 Specifications :
*
Nominal Voltage : 3.7V
Capacity : 1600mAH

*18650 Protected Specifications :

*Nominal Voltage : 3.7V
Capacity : 2200mAH



Of course...I would love the highest capacity available...and I'm not totally needing to go with AW, but if you were to pick between these two, can you tell me which one and why?


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## Fallingwater (Jan 5, 2009)

*I* would go for 2500mAh Trustfires instead, but then again I'm a penny-pincher. 

If I wanted to buy AW cells, however, I'd go for 2400/2500mAh ones (I assume he sells those too).

I've found LiIon cells to be safe enough that the added safety of IMR and LiFePO4 chemistries doesn't quite make up for the lower energy density. Personally I'll stick to LiIon until someone manages to make cells with safe chemistries that hold as much or more energy and cost about the same.


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## 45/70 (Jan 5, 2009)

As I've said elsewhere, with few exceptions, I only buy LiCO cells, for most of the reasons Fallingwater stated. Cost is not a concern however. I do hope to see improvements in the alternative Li-Ion forms.

As has been mentioned in a lot of threads, LiCO's need to be understood, not avoided.

Dave


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## Bullzeyebill (Jan 5, 2009)

Right now I have no use for the IMR18650 high amp discharge cells, so my pick is a high capacity 18650, 2200-2600mAh. If you are using incan bulbs that are pulling 4-20 amps from the cells then you will prefer the IMR18650's.

Bill


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## bullfrog (Jan 5, 2009)

I used to be an insurance broker so I'm always concerned with weighing risk so take my opinion with a grain of salt 

I know there is a very very slim chance of a LiCO cell going  but I don't care - to me it is not worth the risk when the reduced capacity of IMR and LifeP04 is acceptable and enough for all my uses so far.

If I am really really concerned with looooong runtime and am in a situation where I have to 100% rely on the light, I will just use primaries.

It really all depends on how badly you need longer runtime and how often you can charge your cells:

Is this just for using the light around the house for menial tasks? 10 minutes here and there? Walking the dog? or for bumps in the night? If yes, I would stick with IMR because you can just slap the cells on the charger easily or have a second set ready to swap out.

If you use your light for 45+ mins at a time, maybe LiCO make sense...

So... what are you using the light for? :naughty:


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## Sgt. LED (Jan 5, 2009)

I am mostly LED and when I am not I am a 500 lumen incan guy so for now I have no real need for the IMR cells since my draw isn't all that heavy.

What are wanting these to go in?


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## Ryanrpm (Jan 5, 2009)

These will be going into LED throwers. Having them on 40 minutes at a time may be rare, but will happen from time to time. My main goal is to just invest in the best 18650 battery with the highest capacity using today's technology.


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## Toaster (Jan 5, 2009)

IMR 18650 for all the reasons bullfrog listed. Even the reduced capacity is more than adequate. It still provides around the same runtime as 2xCR123 primaries. And now I don't ever have to worry about the protection circuit failing and the battery exploding due to any unforseen circumstances or careless behavior.


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## 45/70 (Jan 5, 2009)

bullfrog said:


> I used to be an insurance broker so I'm always concerned with weighing risk........
> 
> ........If I am really really concerned with looooong runtime and am in a situation where *I have to 100% rely on the light*, I will just use primaries.



I would do the same, if possible. Lithium primaries have no equivalent as far as power available for their size/weight. However, *once again*, I see a statement that implies that lithium primaries are safer than LiCO Li-Ion's *in a light*.

While any lithium chemistry cell type, could be a risk, instances are very rare. I know of no instances of a LiCO Li-Ion exploding in a light, where as there are many examples of this happening or nearly happening with lithium primaries on these forums.

Once again, I'll say it. Lithium primaries are more likely to blow up *in your pocket* than LiCO Li-Ion's.

My apologies Ryanrpm, but this fact seems to just vanish into thin air, regarding a lot of the members of these Forums.

Dave


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## svinfinity45 (Jan 6, 2009)

Wasn't there just a thread on here about how Li-ion cells have gotten a bad name because of mostly user error? I think if you buy AW protected and also use a proper charger, the risk is so small that it's worth the density. But everyone looks at risk differently...


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## xpea (Jan 6, 2009)

Ryanrpm said:


> These will be going into LED throwers. Having them on 40 minutes at a time may be rare, but will happen from time to time. My main goal is to just invest in the best 18650 battery with the highest capacity using today's technology.


I have a Dereelight CL1H v4 3SD driven at 1.2A and I use only high capacity Samsung 18650 cells (2600 and 2800mah) with great success. Did long term runtime last week with my 2800mah cells and no problem to reach 1 hour 44min where AW2200 stops at 1 hour 25. Good improvement in my opinion.


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## rayman (Jan 6, 2009)

I don't really need the IMR 18650. Maybe in future for some mod but not right now. My only 18650 flashlight is the Jet-III Pro and it runs perfectly on protected AW 18650. So no need for IMR 18650.

rayman


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## harddrive (Jan 6, 2009)

xpea said:


> I have a Dereelight CL1H v4 3SD driven at 1.2A and I use only high capacity Samsung 18650 cells (2600 and 2800mah) with great success. Did long term runtime last week with my 2800mah cells and no problem to reach 1 hour 44min where AW2200 stops at 1 hour 25. Good improvement in my opinion.



What was the voltage of each of the cells after the light stopped? I assume the Samsung are unprotected so it was the low voltage protection of the Dereelight that shut it off?

I also use almost only LED so protected AW for me. I would worry with the IMR that I might over discharge them as they don't have a protection circuit.


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## mdocod (Jan 6, 2009)

I will not be participating in the poll because the answer is application specific. 

I'm going to lay out a few things to consider:

Most LED lights contain regulation circuits that can drag voltages below the ideal minimum recommended discharge voltages for either LiMn or LiCo cells. At least with a protected LiCo cell, you are only slightly over-discharging before the protection stops you from severely over-discharging the cell. With unprotected LiMn cells, you are prone to wind up severely over-discharging the cells, which is going to really kill capacity and cycle life if done repeatedly. On lights that run in direct drive towards the end of the discharge this is not an issue (buck-only regulated lights on 1 li-ion cell) as you will see major dimming before either is dramatically over-discharged. 

The total stored energy of 2xCR123s, compared to 1x LiCo 18650, compared to 1x LiMn 18650 is hard to compare and requires first that you know what the load is. The 2xCR123 cells will beat the other two in SLOW drain applications, like 2+ hours. The LiCo 18650 starts to pull ahead of the CR123s when used in applications with ~1 hour runtime. The LiMn cell will beat both of the others in applications where you are pulling serious amps and just need a ton of power density. There are more issue to consider, especially the fact that most lights that are compatible with both an 18650 and 2xCR123 cells are not going to run in regulation on a single 18650, so the runtime on the 18650 is nearly double what it is on CR123s, but is diminishing output rather than regulated output. 

Protected LiCo cells are very safe when used in proper applications, charged correctly, and disposed at the proper point in their life. LiMn chemistry is technically safer because if something does go wrong with it, it does not produce it's own oxygen during a burn. Both cell chemistries can burst, but the LiCo is more likely to produce additional fire and toxic fumes as a result. Both cell types usually come with PTC devices which will sever the electrical connection in the even of over-heating in an attempt to prevent thermal runaway. If the LiCo chemistry bothers you, then owning CR123s should bother you 10X as much.

My general recommendation is to stick with protected LiCo cells for any application with ~45 minutes or more runtime on the LiCo cell in question, especially regulated LED lights. Take advantage of the improved runtime of the LiCo cell. LiMn chemistry is best suited to making high power applications possible in smaller places, like a 1xRCR123 size light driving a P7 to ~2.8A, or a 2x18650 driving a bulb that draws over 3.5A.


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## Ryanrpm (Jan 7, 2009)

Thank you all for your insightful information and views about batteries. The good thing is, these batteries only cost us about $15/ea give or take a few$$, so if I need or want others in the near future, it is only a few mouse clicks away.

I went and purchased 1 Protected AW 18650 2200mAh with Ultrafire 139 charger from Lighthound. I'm sure I won't be disappointed as AW, from what I hear, has a good quality product in batteries.

Those Samsung high capacity batteries look very interesting to me. Perhaps when they get more widley known, are more easily available, and have gone through more testing by CPFers, then I'll invest in a few.


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## Wattnot (Jan 7, 2009)

mdocod beat me to it . . . 

This poll would be like having to decide between a phillips and flat blade screwdriver. 

The recent rash of fears over lion cells is very odd and has no foundation except maybe some newbies asking questions. They are perfectly safe if you follow basic precautions and completely safe if you choose the protected ones.

The IMR cells are for high current draw applications. They should not be desirable otherwise. The cost is greatly reduced capacity. I used them in my M6 and they worked great. 

AW cells are great and I've had great luck with Trustfire's too.


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## DHart (Jan 13, 2009)

I am planning to drive a Malkoff P7 lamp 9v (unregulated) with an 18650 cell... am I better off using an AW IMR or an AW protected 18650? I'm not too concerned with long run times with this light.

Alternatively, I will also be driving a Malkoff M60 9v lamp (regulated) with two rechargeable 123's. Would AW IMR 123's be a good choice here or am I better off with protected 123's? Longer run time would be nice, but not critical.

I don't know enough yet to know about what kinds of lamps demand high current.

Thank you for the help.


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## etc (Jan 13, 2009)

xpea said:


> I have a Dereelight CL1H v4 3SD driven at 1.2A and I use only high capacity Samsung 18650 cells (2600 and 2800mah) with great success. Did long term runtime last week with my 2800mah cells and no problem to reach 1 hour 44min where AW2200 stops at 1 hour 25. Good improvement in my opinion.



Tell me more about these cells, where do you get them?

Are they protected? (Do they need to be? MY Pila charger stops charging at 4.2V, so I thin I would only be concerned about the discharge)


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## Bullzeyebill (Jan 13, 2009)

AW's protected 18650's can be run at 1 1/2C safely, about 3.2amps. For max light output I would go with these cells rather than the IMR's which have reduced mA's. You will want the IMR's when the amp drain is in the range of 4amps. The amp draw for the P4 could be in the range of 2.4-3.2A's.

To answer second question, you could use either IMR123's or AW's protected RCR123's. Protected would give you longer run time, something you might appreciate in a two cell light.

Bill


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## DHart (Jan 13, 2009)

How does one determine what the amp draw (drain) is with a given lamp head?

Gene Malkoff tells me that the IMR batteries should be fine with his M60 and P7 lamp assemblies, but I have no idea how to know what constitutes a high amp draw head.... I have a lot to learn.


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## mdocod (Jan 13, 2009)

DHart said:


> I am planning to drive a Malkoff P7 lamp 9v (unregulated) with an 18650 cell... am I better off using an AW IMR or an AW protected 18650? I'm not too concerned with long run times with this light.



Doesn't matter much here, You can go either way, the protected LiCo cell will run ~30% longer if you want that. 



> Alternatively, I will also be driving a Malkoff M60 9v lamp (regulated) with two rechargeable 123's. Would AW IMR 123's be a good choice here or am I better off with protected 123's? Longer run time would be nice, but not critical.
> 
> I don't know enough yet to know about what kinds of lamps demand high current.
> 
> Thank you for the help.





me from above in this thread said:


> Most LED lights contain regulation circuits that can drag voltages below the ideal minimum recommended discharge voltages for either LiMn or LiCo cells. At least with a protected LiCo cell, you are only slightly over-discharging before the protection stops you from severely over-discharging the cell. With unprotected LiMn cells, you are prone to wind up severely over-discharging the cells, which is going to really kill capacity and cycle life if done repeatedly. On lights that run in direct drive towards the end of the discharge this is not an issue (buck-only regulated lights on 1 li-ion cell) as you will see major dimming before either is dramatically over-discharged.



Drain rates over ~1.5C for a LiCo cell in question should be considered candidates for IMR (LiMn) cell consideration, 2C is the maximum recommended drain rate for most LiCo cells, so that's the cutoff point where you have to switch over to LiMn chemistry to maintain safety. Using IMR cells in applications where they can be repeatedly over-discharged should be avoided, this means most regulated LED lights, unless they have a reliable low-voltage cutoff built in, (it will be an advertised feature if they do)

"C" rates have to do with time. A "2C" rate means 30 minutes to fully charge or discharge. 1C means 60 minutes, 0.5C = 2 hours, 4C = 15 minutes. Higher C rates translate to shorter runtimes. 

Eric


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## mdocod (Jan 13, 2009)

DHart said:


> How does one determine what the amp draw (drain) is with a given lamp head?



It can be measured with a current-meter by putting the meter in place of the tailcap of most tactical flashlights. (current must pass through the meter to complete the circuit), or it can be estimated on paper if you know some information about the module. 

Here's an example for an M60:

According to Gene, the M60 draws 750mA at 6V, and the module should run in regulation from ~3.8V up to ~9V. So the total power consumed should be very similar across this range.

Convert power consumption to watts: 0.75A x 6V = 4.5W

Choose an input voltage to recalculate for: 7.4V

Calculate new load: 4.5W / 7.4V = ~608mA

That would be an approximate average load for cells that AVERAGED 3.7V per cell into this module. Such estimates are not always going to be 100% accurate because we don't know the exact voltage that we can expect to deliver under a load. For the IMR cells, the average voltage into this load through a discharge would likely be a little higher, maybe more like 7.6V or more. which would translate to lower average current through the discharge. 

-----------

Different modules have different behavior, so this concept does not translate to any module out there. Most boost regulated modules are not very linear from their lower to higher ranges of operation in total power consumption, and their efficiency changes dramatically at lower input voltages, so paper estimates basically just require more in-depth knowledge of the driver being used. Direct drive configurations can be even more difficult to estimate, and honestly, just have to be tested to see how long they run to really get anything accurate. 

Eric


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## DHart (Jan 13, 2009)

Eric... your primers (stickies?) linked to at the bottom of your posts are *incredible* contributions to newbies like me. So very helpful. I'm still working my way through them to try to get my knowledge around this topic a little better. So thank you very much for those works of sharing, along with your help here.

In working through the example you gave for the M60, when you arrive at the calculated "load" of ~608mA, does that mean the current or the draw of the lamp is about 608mA? If so, would that be considered high current for flashlight applications? (Suitable for IMR batteries)?

It seemed from my conversation with Gene that he liked the IMR batteries and felt they would be a good source for his P7 and M60 lamps... he didn't say that I *should* use IMR, just that they would be fine. I just ordered some AW IMR cells from Lighthound (shipped today)... so now with a little more education, I'm starting to wonder if I would be better off with AW protected cells instead and should see if I can return the IMR's. If the protected cells will be just as good with the P9 and M60 and will give longer life, and less likely to over discharge.... I'm second-guessing my choice.


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## mdocod (Jan 13, 2009)

DHart said:


> Eric... your primers (stickies?) linked to at the bottom of your posts are *incredible* contributions to newbies like me. So very helpful. I'm still working my way through them to try to get my knowledge around this topic a little better. So thank you very much for those works of sharing, along with your help here.
> 
> In working through the example you gave for the M60, when you arrive at the calculated "load" of ~608mA, does that mean the current or the draw of the lamp is about 608mA? If so, would that be considered high current for flashlight applications? (Suitable for IMR batteries)?



I'm glad you are enjoying the guides, they are still works in progress and with so many changes going on lately it's going to take a lot of work to get them up to speed. I need to dedicate some serious hours to getting those compatibility charts up to speed. They are stickies, one can be found in the "threads of interest" in the "batteries/electronics" section, the other in the "incan" section of this forum.

The "608mA" (0.608A) is the approximate current that the M60 would draw from a 7.4V power source. Nailing down what a "high" or "low" load is for a particular application is all relative and depends on what cells are "dealing" with that load. 

An AW brand protected RCR123 is rated ~750mAH capacity, and delivers ~500-600mAH more realistically. So a 608mA load would drain the cell in a little less than an hour. The maximum recommended safe discharge rate for this type of cell, is ~2C, or ~30 minutes, which translates to about 1.2A (1200mA) discharge rate. So in this application, the 608mA load is perfectly reasonable. Most li-ion applications in consumer devices have runtimes of 2-10 hours give or take, so from that perspective, you could say that the load is a little higher than normal for li-ion cells in general, but still well within manufacture recommendations.

Take the same 608mA load, and run it with a pair of 2200mAH 18650 size cells, and now the load is only ~0.25C, runtime approaching 4 hours, which is a nice conservative load for the cells that is very very safe. 



> It seemed from my conversation with Gene that he liked the IMR batteries and felt they would be a good source for his P7 and M60 lamps... he didn't say that I *should* use IMR, just that they would be fine. I just ordered some AW IMR cells from Lighthound (shipped today)... so now with a little more education, I'm starting to wonder if I would be better off with AW protected cells instead and should see if I can return the IMR's. If the protected cells will be just as good with the P9 and M60 and will give longer life, and less likely to over discharge.... I'm second-guessing my choice.



For the M60 module, it would be fine to run it on a single IMR cell (16340 or 18650), it would not run in regulation through the entire discharge, but would work reasonably well, you would see a LOT of dimming towards the end before the cell would be over-discharged, but when you stack 2 cells in series, there is no drop in output until the cells are severely over-discharged. So for single cell applications, IMR type cells would be fine for the M60.

The P7 module when driving on a single 18650 can work well on either a protected 18650 (longer runtime) or an IMR18650 (possibly slightly higher average output through the run, but with less runtime). 

However: For "3P" size configurations with the P7 module, the IMR16340 is a requirement, as the smaller RCR123 size LiCo cell can not safely drive the load of a P7 (over 2 amps). As I was saying above, the maximum safe discharge rate of a typical protected RCR123 is around 1.2A, but an IMR16340 can handle over 4 amps safely, 

....and since the P7 module is direct drive, you would see plenty of dimming before over-discharging a cell so you could manually terminate the discharge to keep the cell healthy.

Eric


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## DHart (Jan 13, 2009)

mdocod said:


> For the M60 module, it would be fine to run it on a single IMR cell (16340 or 18650), it would not run in regulation through the entire discharge, but would work reasonably well, you would see a LOT of dimming towards the end before the cell would be over-discharged, but when you stack 2 cells in series, there is no drop in output until the cells are severely over-discharged. So for single cell applications, IMR type cells would be fine for the M60.



Interestingly, Gene told me very specifically, several times, that the M60 MUST be used with two cells and never with one. That kind of surprised me, but my knowledge of this is close to zero. Do you know why he would say that the M60 must only be used with two cells?



> The P7 module when driving on a single 18650 can work well on either a protected 18650 (longer runtime) or an IMR18650 (possibly slightly higher average output through the run, but with less runtime).
> 
> However: For "3P" size configurations with the P7 module, the IMR16340 is a requirement, as the smaller RCR123 size LiCo cell can not safely drive the load of a P7 (over 2 amps). As I was saying above, the maximum safe discharge rate of a typical protected RCR123 is around 1.2A, but an IMR16340 can handle over 4 amps safely,
> 
> ....and since the P7 module is direct drive, you would see plenty of dimming before over-discharging a cell so you could manually terminate the discharge to keep the cell healthy.Eric



As for the P7 module, Gene made the exact opposite statement from the M60. He very clearly told me NOT to drive the P7 with more than a single cell, period. Again, I don't know why, but your thoughts on that would also be much appreciated! Thank you.


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## mdocod (Jan 13, 2009)

DHart said:


> Interestingly, Gene told me very specifically, several times, that the M60 MUST be used with two cells and never with one. That kind of surprised me, but my knowledge of this is close to zero. Do you know why he would say that the M60 must only be used with two cells?



He may have been talking about CR123s in that case? The M60 will not run on a single 3V cell, but will run on a single 3.7V li-ion cell reasonably well. I'm not sure why he may have advised against using a single cell in this case, my guess would be that he is advising configurations that result in the best possible performance, and a single li-ion cell driving the M60 would not result in the best possible performance.





> As for the P7 module, Gene made the exact opposite statement from the M60. He very clearly told me NOT to drive the P7 with more than a single cell, period. Again, I don't know why, but your thoughts on that would also be much appreciated! Thank you.



Since the P7 module is direct-drive, with no boost or buck circuit to protect the LED from variations in input voltage, using anything but a single 3.7V li-ion cell to drive it would not work. Using a 3V cell would result in terribly dim output, using 2 of any cells (3V or more per cell) would fry the LED instantly.


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## DHart (Jan 13, 2009)

Eric... again, thank you. Your help and counsel is so very much appreciated. 

Based on what I'm hearing about the IMR cells, I'm going to see if Lighthound might exchange back the AW IMR's I ordered (18650's and 16340's) for AW Protected cells... they haven't even arrived yet, so it's not like I've even opened the packaging yet. Don't know if this is possible to exchange, but I guess it's worth a try.

I'm looking to drive my M60s with pairs at all times, either two AW 16340's, a pair of AW 17500's, a pair of 17670's, or a pair of AW 18650's - depending on what tubes/extensions I use. Any of these combinations should work fine, correct?

And with the P7 module, I was planning to drive it with a single AW 18650 or a single AW 17670.


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## Mikellen (Jan 14, 2009)

I just purchased an Olight M20 Premium R2 flashlight and would like to start using a rechargeable 18650 battery. I'm very new to learning about the different battery chemestries and must admit I don't understand much about them. Can someone please recommend what type of 18650 battery and charger I should purchase? My main goal would be safety of the cells and charging, and also ease of operation. I just would like to keep it simple and be able to charge and use the 18650 battery without too much concern. If this is my goal should I just stick with CR123A (primaries)?
Also are the different 18650 battery types (LifePO4, IMR, AW etc.) similar in weight? Do they weigh more than say 2 CR123A batteries? Just trying to keep the flashlight as light as possible.

Thanks for any responses.


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## mdocod (Jan 14, 2009)

Mikellen said:


> I just purchased an Olight M20 Premium R2 flashlight and would like to start using a rechargeable 18650 battery. I'm very new to learning about the different battery chemestries and must admit I don't understand much about them. Can someone please recommend what type of 18650 battery and charger I should purchase? My main goal would be safety of the cells and charging, and also ease of operation. I just would like to keep it simple and be able to charge and use the 18650 battery without too much concern. If this is my goal should I just stick with CR123A (primaries)?
> Also are the different 18650 battery types (LifePO4, IMR, AW etc.) similar in weight? Do they weigh more than say 2 CR123A batteries? Just trying to keep the flashlight as light as possible.
> 
> Thanks for any responses.



For trouble free operation, your best bet is to get a Pila IBC charger and a few AW brand protected 3.7V 18650 cells. 

With those cells and that charger, I would give it a safety rating and ease of use similar to any laptop or cell phone. You can plop the cells on the charger at any time, forget about them for as long as you want, and they will not be over-charged.


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## Kestrel (Jan 14, 2009)

DHart said:


> I'm looking to drive my M60s with pairs at all times, either two AW 16340's, a pair of AW 17500's, a pair of 17670's, or a pair of AW 18650's - depending on what tubes/extensions I use. Any of these combinations should work fine, correct?


 

All of that would work. The reasons why I think 2x17500 is preferable for running an M60:

These fit into a stock SF 9P/C3 body length, which is the longest flashlight that fits into a pocket comfortably, imo. (The Centurion body style has quite a following BTW: https://www.candlepowerforums.com/threads/206975)
This is the same length as 2xAA. In a pinch, drop your 3v M30 into this body, the M30 runs great from 2xAA alkalines (a regulated 130 lumens for an hour with an additional ~30 minutes of declining light), giving you an inexpensive backup option.
This body length can take 3x3.0v CR123 primary (non-rechargeable) batteries as a backup option for the M60/2x3.7v rechargeable setup. The M60 is a 6-9v module which means it runs great on 2 or 3 3.0v 123's, but not 4. The 2x17670/18650 bodies & the M60 cannot run backup primary 123's without a battery spacer (wasted space and more potential problems)
2x17670/18500 means an aftermarket body, which I'm just not into. A personal preference thing, lots & lots & lots of folks here love their FM and Leef bodies.
It is definitely giving up some runtime over the larger capacity options, but there are many backup (non-rechargeable) power options for the 9P/C3 body length. If more runtime is needed, the M60L is a viable option for 2-3x more runtime.
There really isn't a viable backup power option for the 2x17670/18650 bodies after your rechargeables are depleted.

However, we seem to have gotten off-topic. My apologies to the OP.


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## Kestrel (Jan 14, 2009)

My apologies to the OP, we seem to have gotten off-topic. Sorry.


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## DHart (Jan 14, 2009)

Kestrel.... ONCE AGAIN! you are da man! I totally concur with your analysis and conclusions... You got it nailed! (I think/hope I would have arrived at your conclusions sooner or later, but you just helped me get there WAAAY sooner!) :thumbsup: So... hmmmmm... what else ya got to suggest?


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## SemiMan (Jan 14, 2009)

Given the higher voltage over it discharge cycle of the IMR batteries, are we likely to see higher degradation in even the partially charged state versus cobalt based Lithium Ion? Seems to me that even 50% discharged, these will degrade a lot at room temperature if I understand the mechanism properly.

Semiman


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## Kestrel (Jan 14, 2009)

DHart, we seem to have gone off-topic from this thread.

I'm afraid I don't have all the answers, just some opinions. I've learned a lot of what I know from reading many helpful & well-thought-out posts by *Sgt. LED*,* mdocod*,* Rat6P*,* Bullzeyebill* and others, they're the heroes.

But this thread is about IMR vs. standard LiIon...


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## mdocod (Jan 14, 2009)

SemiMan said:


> Given the higher voltage over it discharge cycle of the IMR batteries, are we likely to see higher degradation in even the partially charged state versus cobalt based Lithium Ion? Seems to me that even 50% discharged, these will degrade a lot at room temperature if I understand the mechanism properly.
> 
> Semiman



Not exactly sure if I understand this question, but from what I understand, LiMnO2 (IMR) chemistry rechargeable cells should last as long or longer than LiCoO2 cells, as far as "storage life" is concerned. The chemistry is more stable in theory...

I will try to do some hunting around the internet to find more relevant information on this topic as you have sparked my curiosity a bit.


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## Kestrel (Jan 14, 2009)

mdocod said:


> I will try to do some hunting around the internet to find more relevant information on this topic as you have sparked my curiosity a bit.


This is like having a full-time researcher on-call. You sir, are an asset to CPF.:thumbsup:


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## DHart (Jan 14, 2009)

Kestrel said:


> DHart, we seem to have gone off-topic from this thread.... But this thread is about IMR vs. standard LiIon...



Yes... sorry for drifting off here....


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## datiLED (Jan 14, 2009)

Protected 18650 2200mAh - Quality and runtime.


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## etc (Jan 14, 2009)

Kestrel said:


> All of that would work. The reasons why I think 2x17500 is preferable for running an M60:
> 
> These fit into a stock SF 9P/C3 body length, which is the longest flashlight that fits into a pocket comfortably, imo. (The Centurion body style has quite a following BTW: https://www.candlepowerforums.com/threads/206975)
> This is the same length as 2xAA. In a pinch, drop your 3v M30 into this body, the M30 runs great from 2xAA alkalines (a regulated 130 lumens for an hour with an additional ~30 minutes of declining light), giving you an inexpensive backup option.
> ...



A Leef or FiveMega 2x18500 body doesn't really have any disadvantages over stock Surefire 9P body, other than cost. You can still run 2xAA in it and 3x123 PLUS you can run 2x18500, more choices.

I agree about 2x18650 being a problem but you can find a module that runs off 12V. I talked to Malkoff, he says that he cannot build an M60 module accomodating 12V. Now, anyway.


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## jasonck08 (Jan 14, 2009)

AW's are too expensive. Is it something like $12 for a single 18650 protected cell + shipping? I can get 4x 18650 ultrafires for the same price shipped from DX. They just dropped the 18650 ultrafire price to $7.50 shipped for a set of 2.


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## etc (Jan 14, 2009)

If you think AW is expensive, you should try Pila cells. 

I thought about getting some, but the thought of paying $40+ for a pair scares me, plus I am waiting for a high capacity protected 18650s. 

I don't need them urgently so can afford to wait a year or two. High capacity 18650 are already here, so it's just a matter of time before someone makes a protected 2900 mAh 18650 cell.

IMO investing in lower capacity is investing in obsolete techology. Else they will have a huge sale and at 40% off I might buy some.

P.S. I wouldn't want to save pennies with Li-Ion, it's chemistry and potentially deadly stuff. Get the best you can afford. This is not some alkaline stuff. Remember the laptop cells which set on fire?


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## Kestrel (Jan 15, 2009)

Kestrel said:


> My apologies to the OP, we seem to have gotten off-topic. Sorry.





etc said:


> A Leef or FiveMega 2x18500 body doesn't really have any disadvantages over stock Surefire 9P body, other than cost. You can still run 2xAA in it and 3x123 PLUS you can run 2x18500, more choices.
> 
> I agree about 2x18650 being a problem but you can find a module that runs off 12V. I talked to Malkoff, he says that he cannot build an M60 module accomodating 12V. Now, anyway.


I have stated three times in my posts in this thread that I have went off-topic, and I have made a point of apologizing to the other members here.
Etc, how have you gotten the idea that it is appropriate to explore this topic further, after reading my requests to get back on-topic?


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## lyyyghtmaster (Jan 23, 2009)

The Zebralight H60 is said to cut off at 2.8V to protect the cells. While this is above the minimum recommended discharge voltage for an IMR, it seems too low to obtain optimum life cycle performance from these cells if repeatedly relied upon to terminate discharge, especially at the lower brightness levels. Is this indeed so, or are these cells different in this regard?

At what voltage does the protection circuit in AW's cells cut off discharge?

Any thoughts about strapping a (protected) LiCo Liion to one's forehead? 

:thinking:

Thanks!


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## 45/70 (Jan 23, 2009)

lyyyghtmaster said:


> Any thoughts about strapping a (protected) LiCo Liion to one's forehead?



OK. One more time. LiCO Li-Ion's are not going to blow up on your forehead, or in your pocket. In other words, no, I wouldn't have any thoughts on wearing either an *unprotected* or protected Li-Ion on my forehead. The danger (which is *very unlikely*, if the cells are properly used and monitored) with LiCO Li-Ion's, is when trying to recharge an over discharged, or otherwise damaged cell, *in the charger.*

I have no problems with IMR Li-Ion's. They are superior at very high discharge rates. In these situations they are safer however, unless your headlamp is driven @25+ watts from a single 18650, it really isn't necessary to use IMR's. Of course, there's nothing wrong with using them, they just offer less capacity.

Dave


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## mdocod (Jan 24, 2009)

I also have no fear of strapping LiCo cells to my forehead, I've probably had a LiCo on my forehead longer than most people here have even used their flashlights, as I use a 17670 in an Argo HP for hours on end, often several days a week, while building battery adapters. I am actually far more comfortable loading it with a 17670 LiCo cell, than I am loading it with CR123s, as CR123s are the ones that are known to explode during discharge in certain circumstances.


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## LuxLuthor (Jan 24, 2009)

The question depends entirely on the amps needed. If you need more than 5.5A, have to go with Li-Mn. Your poll question is like asking "You decide -- a screwdriver or pliers, and why."


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## lyyyghtmaster (Jan 25, 2009)

Thanks, guys, that's pretty much what I was thinking. I was just looking for some more confirmation from those more experienced on the subject before I pulled the trigger for the protected 18650s. I agree that I am more afraid of my CR123s than my (properly charged) protected LiPo 9V batteries. And I don't even have any of the disreputable-name CR123s at all. I will go with the standard LiCo cells, since I don't as yet have an LED light of such power as to necessitate an entire LiMn cell. :mecry:

Although now I'm a little worried about how badly some have said those cells fit that light.... :sigh:


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## Ryanrpm (Jan 25, 2009)

LuxLuthor said:


> The question depends entirely on the amps needed. If you need more than 5.5A, have to go with Li-Mn. Your poll question is like asking "You decide -- a screwdriver or pliers, and why."



Shows you how much I know about batteries, huh?

Sorry for the vagueness then. This is going into the RQ, Spear clone. Probably not more than 1a is needed.

I've already purchased the AW protected 18650 w/charger.

Thanks everyone for your insight, and I'm glad the discussion carried on well past my needs.


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## GarageBoy (Jan 25, 2009)

When should you yank the IMR cells before you kill them when using an incan lamp? I really wish they would put in overdischarge protection on them


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## Bullzeyebill (Jan 25, 2009)

GarageBoy said:


> When should you yank the IMR cells before you kill them when using an incan lamp? I really wish they would put in overdischarge protection on them



I would think that you should change them out when using, for example, two to drive a 9 volt lamp (actual 7+ volts) and the lamp starts dimming. Around 5.5 volts it will be obviously dimming. 

As I have been told, and it makes sense, adding a protection circuit to an IMR Li Ion cell will reduce its capacity, and greatly reduce it best feature, lots of amperage under heavy loads.

Bill


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## DHart (Jan 25, 2009)

GarageBoy said:


> When should you yank the IMR cells before you kill them when using an incan lamp? I really wish they would put in overdischarge protection on them



I'm no expert, but from what I've learned here, recharging lithium cells can and should be, ideally, done somewhere in mid cycle. They don't have a memory problem, so you can top them off whenever it's convenient. SO just charge the puppy up now and then as you think about it... don't bother trying to run it as low as you safely can before recharging it. Periodic testing with a voltmeter never hurts either.


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## Bullzeyebill (Jan 25, 2009)

DHart said:


> I'm no expert, but from what I've learned here, recharging lithium cells can and should be, ideally, done somewhere in mid cycle. They don't have a memory problem, so you can top them off whenever it's convenient. SO just charge the puppy up now and then as you think about it... don't bother trying to run it as low as you safely can before recharging it. Periodic testing with a voltmeter never hurts either.



+1. I am constantly monitoring my LiIon's, even the protected ones. :thumbsup:

Bill


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## RGB_LED (Jan 26, 2009)

DHart said:


> I'm no expert, but from what I've learned here, recharging lithium cells can and should be, ideally, done somewhere in mid cycle. They don't have a memory problem, so you can top them off whenever it's convenient. SO just charge the puppy up now and then as you think about it... don't bother trying to run it as low as you safely can before recharging it. Periodic testing with a voltmeter never hurts either.


+2... I usually do not allow any of my cells to come close to the over-discharge except on rare occasions and strictly by accident as I usually bring along plenty of spares. I then closely monitor my chargers when charging CR123's, 17670s and 18650s.

As an aside... I have to commend mdocod; my hat's off to you for some fantastic information... a lot of what I learned about LiCo and LiMn cells have come from your posts. The information you provide helps many to understand the misconceptions that exist about Li-Ion cells. You are definitely an asset on this forum and I would like to thank you! :thanks::goodjob:


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