How to use Pilas in SF M-4 ?

If I want to switch over to using Pilas instead of the four 123a's in my SF M-4, can you tell me how many, and which model of Pilas to get, and also which replacement bulb (and where to get them)?

Thanks!

Hi, I will try to help. 2 168s will fit and run the lamps for the M3T MN15 MN16 or the N2 that is impossible to find right now. If you have 2 A19's you can run the M4 Lamps MN60 MN61 with 3 168s I do this quite often. If you have just 1 A19 I guess (never have but sure I could) run 3 150s with a spacer. You may or mat not need the spring Jon has provided in the past. I have been warned the running 3 168s or any 3 Li-ion is not a good idea however I have not had any problem with the Pila cells. I hoped that helped.
Topper

Topper, thanks for the reply....but you completely lost me in terms of all the abbreviations. What are these items, and where do you get them?

Sorry for being so stupid about all this, but I do appreciate your help.

Hi LuxLuthor, go to surefire.com and put all those names in the search function, you get nice pictures with it there...
here's a pic of the A19 from the supremeco website
the 150s's are rechargeables, 1.5 x 123 size
Jon is J.S.Burly's, a good source of Pila rechargeable batteries
spacers and springs are custom made bits that will make your batteries fit....

hope I saved you some time, Topper :wave:

Thank you rikvee, I am half asleep but it is time to go to work.LuxLuthor, I will send a PM if you want this afternoon however it looks like rikvee has it covered very well. I will check this thread in about ten or eleven hours to see if you need more or better detailed answers.
Topper

Topper, I ssume that you let the 168S's "cool down" a bit rather than use them straight from the charger when using 3 of them with the MN60/61?

Excellent....now I know what it all means and where to look. Thanks rikvee and the rest! Yeah, FiveMega told me the same thing about letting freshly charged Pila's/AW's sit for 12-24 hours to stabilize the initial high charge voltage, before using in order to preserve the lamps.

In the case of LiIon rechargeable cells, there really is no such thing as "resting" or "hot off the charger" delays. Thats a huge phenomenon with NiMH. However, there is something to the notion of taking the cells out of the charger early for a safety margin with certain incan lamps. LiIon charges at constant voltage, usually 4.2 or sometimes slightly higher, variable current.

On Pila brand chargers, the LED turns green indicating "done" when the cell is at only 4.08-4.09V, but when left on the charger for a significant time after green LED is on it "trickles" upward very sowly to final out around 4.19V. DSD chargers (common 4-bay 2-way LiIon chargers from Lighthound AW eBay and others) do the same thing.

Interestingly, the much cheaper DSD chargers limit the ultimate charge voltage to a safe 4.20V regardless if the cell is protected or unprotected, but using an unprotected cell in a Pila charger will escalate to unsafe levels (I accidentally observed 4.60V with 2 unprot cells in a Pila charger left unattended for several hours - the 1st and LAST time I'll ever do that - nothing happened but I was scared) because it counts on the prot circuit in the cell to say thats all folks.

So unless you check with a DMM its a pretty good bet you will get slightly less than to-the-brim with LiIon batteries if you plop them out the first moment the LEDs turn green indicating done. 0.12V may not seem like much but to some incan bulbs can be life or death. Protected cells dont have to worry at all. In my experience yuo pull a cell off the charger at 4.14V, in a month of shelf duty they are right at 4.14V where I left them. By the way, I dont have exact figures but charging only to 4.1 instead of a full 4.2 0r 4.25 is almost double the life in charging cycles, the "fuller" you charge you also reduce the lifespan of the rechargeable. The higher the total voltage, the shorter the number of times you can recharge that cell.

Hope this helps!

Topper,

Why do you say that the N2 lamp assembly is not available, if it is listed here at SF's site? Maybe it is backordered from SF, but not indicated?

I'm still a little confused as to which of those combinations would give the best light output. Is the original M-4 MN61 (350 lumen) bulb the brightest option? If so, does using the two A19 spacers which allows you to use three of the Pila 168's give the same voltage and lumen output from the MN60/61 bulbs?

It looks like one of the 168's is the same length as two of the SF 123's. Is there a different voltage that won't drive the original bulb properly if I used two of the Pila 168's, vs. your recommended three 168's with the A19 spacers?

I'm seeing that the 123's have 3 Volts x 4 = 12 Volts.....vs. the 168's have 3.7 V x 3 = 11.1 V

Hi LuxLuthor, The N2 is apparently sold out right now. The MN61 would be the brightest of those mentioned but of course you lose a lot of run time and yes you would need to get 2 A19's or something similar to use 3 168s Pila's. I think the Pila's come off the charger around 4.2 so 3 would make 12.6 volts however I think they sag a little under load as I think all cells do. I do pull mine off as soon as I notice they indicate they are charged. I do not have a L2 but the 150s is roughly the size of 1 and a half cr123 you use 2 for 3 cell lights. Hoped that help some. stuartyr I do wait for the most part. If I think its time to recharge I just do it and install them right back in the light it may be five minutes or five days before I use it other than a quick initial blast to make sure it is working.
Topper

Thanks Topper, and for your PM answers.

So it looks like I should get two of those A-19's because after using FiveMega's 1300 lumen - Mag85 mod with 9 x 150s, I'm addicted to a lot of light....even at the expense of run time.

If I got those two A19 spacers, would that fit exactly so the 3 168's would work? I am assuming each A19 is equal to the exact length of a 123 battery. I do know that one of the 168s is equal to the length of two of the 123's.

Yes, that is what I use on one of my M4's all the time.
Topper

This is now a mandatory order to get two of these A19's, since the 123's are now $1.75 each....well I could get them from batterystation.com I guess....but their prices will eventually go up as well.

So, let me figure this out....adding up the $40 for these A19's & $65 for the 3 168's gives me an investment of $110 (with shipping).

Next I divide $110 by $1.75 for each 123a = 62.86 batteries I could buy for that amount...then again divided by 4 (a full M-4 load of 4 batteries) = 15.7 "20 minute cycles" of M-4 useage with the MN61 bulb.

So if I use the rechargeables for 16 cycles (5.5 hours), I'm ahead of buying the 123a's. That made it an easy decision to go rechargeable.

Thanks Topper, Lunarmodule, and everyone else !!!! :rock:

Lunarmodule said:

On Pila brand chargers, the LED turns green indicating "done" when the cell is at only 4.08-4.09V, but when left on the charger for a significant time after green LED is on it "trickles" upward very sowly to final out around 4.19V. DSD chargers (common 4-bay 2-way LiIon chargers from Lighthound AW eBay and others) do the same thing. ...
0.12V may not seem like much but to some incan bulbs can be life or death.

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Wow, great info. That might explain why my G&P G120 lamp was able to get three good cycles from my Wolf Eyes 150B and 168B cells, only to hot-flash the fourth time. Perhaps the first three times, I eagerly eyed the green LED and removed the cells at <4.1V. I use both Wolf Eyes "smart" chargers (CH02 and DH02) and AW's DSD.

I got my 168s Pilas today from Burlys, and although once charged they work great in the FM Mag 3x168s 700 Lumen mod, for some reason they do not work in my SF M4.

I tried two 168s and then used two A19 spacers, and tried 3x168s, but neither setup would light the MN61 bulb. I also noticed the tailcap did not have that springy push action....like the Pilas are not fitting right?

LuxLuthor said:

I got my 168s Pilas today from Burlys, and although once charged they work great in the FM Mag 3x168s 700 Lumen mod, for some reason they do not work in my SF M4.

I tried two 168s and then used two A19 spacers, and tried 3x168s, but neither setup would light the MN61 bulb. I also noticed the tailcap did not have that springy push action....like the Pilas are not fitting right?

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Are you using JS Burlys' free spring on your lamp?

No. I don't know about the spring. I will contact Jon about it. There is a spring that comes with the M4.....you are saying there is an additional spring needed to make it work?

J.S. Burly will give you the spring for free, just ask for it.

The free spring goes around the stock spring in the head of your M4.

Hoghead said:

J.S. Burly will give you the spring for free, just ask for it.

The free spring goes around the stock spring in the head of your M4.

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You just drop it inside the head (light end), and don't put anything on the tail cap end? Even if I manually put the battery against the tailcap, it still does not have that springy push button feel to it. Do you need another spring in the tail cap end?

LuxLuthor said:

You just drop it inside the head (light end), and don't put anything on the tail cap end? Even if I manually put the battery against the tailcap, it still does not have that springy push button feel to it. Do you need another spring in the tail cap end?

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I screw the free spring around the stock spring in the head. When I take the batteries out to charge, the battery nearest to the head is usually stuck in the end of the free spring. This is normal.

Nothing else to add to the tail.