another M6-R with MN61

Hi all!
I just wanna share what I've been doing .
I dont know if somebody has already done this,
Basically Im using 6 rechargeable Li-ion batteries from ebay (the 3.7V one),
to put inside my Surefire M6 - so the total Voltage is = 11.1V.

then to accomodate this voltage rise, Im using MN61 BULB (for Surefire M4 - 12V one) - bought from cpf member "somelamp"
(hi somelamp!)

And it is working beautifully!!. Cheap 350 lumens.
I've tried to turn it on continuously, and it results with 22 minutes of Full Power light, with these 700ma Li-ion cells.
then about few seconds yellow beam after that (then I turn it off quickly).

I want to post beam shots, but dont have digital camera
(i have a $1000 flashlight in total, but cant afford to buy $200 digi-cam)
*typical flashaholic* hehehe...
I'll try to borrow my friend's digi-cam , and post it here.

Thank you for reading.

kalengkong,

Yes. It has been done before, but so what?

It was good then, and it is good now. And far cheaper than an M6-R I suspect.

I do wonder what the voltage under load is, and how many actual lumens are being produced. It could be MORE than 350! It could be less. We wouldn't know unless someone bench tests this setup to get applied voltage at the lamp.

Still, it doesn't matter too much. I only wanted to point out that despite the Li-ion volumetric energy density advantage over NiMH, an M6-R still manages 630 lumens constant, undimming, for 19 minutes.

I just love that.

Hi js,

no no no , i think, you misunderstand my post.
I didn't put my post here to 'compete' with your M6-R project.
yours is far away more advance than my 'beginner project'.

and actually your M6-R pack is one on my wish-list. but dont have the money now. need to buy a new lcd.

I just want to share my experience here. thats all.

PS: about the lumens, yeah, I dont know how many lumens does it produce, it might be more than the spec said, since the 11.1V is quite high i think.

Kaleng,

Jim wasn't criticizing your post, he was saying that it has been done, but it is still a good modification, especially for the cost!

I should try this, but time is at a premium for me right now.

Bill

I'd be carefull with that many batts in series. Good thing you turned it off at first sign of diming. I wouldn't want one to reverse charge and then have a hand held grenade full of 6 flaming li-ions!!

Kaleng,

What Bill said!

I didn't mean to say anything negative at all about what you've done. It's a good idea!

I only mention the NiMH thing because I am often taken to task for using NiMH, when Li-ion is the "latest and greatest". But even though it is the latest and greatest, I still can manage to best it with my NiMH M6-R pack. Hmmm. Li-ion must not, in all ways at all times in all situations be the best.

Just trying to blunt the favorite axe that some people grind and then try to use on me. Although that hasn't happened for some time now.

That said, two 18650's will direct drive the MN21 nicely and have a decent runtime, although I can't remember how much at the moment. But trying to direct drive the MN21 with two 4/5D Li-ion's would almost certainly insta-flash it when the cells were fully charged. Plus, they wouldn't quite fit, even without protection circuitry. Add the protection circuitry and they definitely WON'T fit.

Another option is to use three Pila 168s's in series in a special holder, which Kiu did back when I was working on the M6-R (but was still keeping it secret) in his Rechargeable in SF M6 (PILA\'s) 2xx lumens thread. This is essentially the same, electrically, as what you are doing. You have two parallel stacks of three R123's; he had one stack of three 168s's. In both cases the open circuit and under load voltages are similar, I would think, although he used the MN60 and you are using the MN61. But there was no reason why he couldn't have used the MN61 as well. Except maybe some caution and concern over the current draw.

In any case, this method that you are using is a drop-in mod, whereas Kiu had to make up a special battery holder. All your method requires is some R123's and an MN61, both of which can be obtained on-line, on demand. No waiting for some slow coach to finish making up a special battery pack or something.

Although, as I said before, I know I read someone doing this. I think it was in the incan forum, and it was about a couple or three months ago now, IIRC.

thanks for all the reply.
I think I missed a lot in this forum, since i've been 'away' for a while.
HMmmm.. I m also worried about the Li-ions in series like that.
thank you for the info guys. you guys really helps me a lot .

js, MN21 with 2 LI-ion? hmmm interesting... hehehe.
I think i would try that one tonight.
(hmmm yea, 7.4V i think will be alright to run MN21) hmm hehehe... i like this.

Okay, just feeling stupid here, but how about Li-Po? They are designed to take MUCH higher current than Li-Ion can at this time, and there are a lot of 11.1volt 2600+MaH packs available on line, all we need is to custom request a shape to fit in the M6...

Granted Li-Pos aren't the safest thing around, but neither is pulling 2-2.5 amps from a series of 3 R123s....

Question: is that using protected li-ions?
I'm guessing not but then why use the M4 HOLA instead of a safer LOLA?

270, I'm with you. For the experienced LiPo user, who is aware of the dangers, you could get some fantastic energy density shoved into an M6... if only the darned rectangular packs would fit nicely. Add a little bit of smarts to either regulate and/or prevent overdischarge, and you're talking about my dream light!

-Trev

The newer Li-ion, especially the 4/5D size, would more than handle the current. No need to go to Li-poly for a 5 amp draw in this case. Even the LG 2400 mAh 18650's will handle the 5 amp discharge--barely, but still, they do it.

The problem, as tch_popeye points out, is that the Li-polys are prismatic cells, and thus don't fit nicely into a round hole. So you loose energy density there. The best energy density would come from the 4/5D's, two of them in series, but made a little bit shorter than standard 4/5D's in order to fit. But then you'd have to worry about instaflashing, or space to fit regulation circuitry of some kind.

And, in point of fact, there are two types of energy densities: gravametric, and volumetric. RC people are much more interested in gravametric energy density: energy per gram. Flashaholics are much more interested in volumetric energy density: engergy per unit volume. And it turns out that NiMH isn't that far behind Li-ion or Li-poly if you use that measure. It is still behind, to be sure, being, IIRC, only 80 percent of Li-ion energy density. BUT, when you start to take into account of high draw rates relative to capacity, then NiMH start to get closer, meet, or even exceed Li-ion or Li-poly volumetric energy density. Not so with gravametric, especially with Li-poly, due to the lack of a metal casing.

Anyway, if we could get two 4/5D's into an M6, and if the MN21 were a bit higher in voltage so that it could safely be direct-driven, or if we just pretend we could fit the regulation circuitry in the tail-cap or something, we'd get on the order of 40 minutes of runtime!

A lot of "ifs" there, though.

js said:

Just trying to blunt the favorite axe that some people grind and then try to use on me. Although that hasn't happened for some time now.

Click to expand...

Jim,

"Udam..."

Wilkey

js said:

Even the LG 2400 mAh 18650's will handle the 5 amp discharge--barely, but still, they do it.

Click to expand...

Aha, that means my ROP/LE design will still have a little bit of leeway. 4 amps here.

Ginseng: better go back into hiding before js grabs the axe and looks for you for mentioning that

Ginseng said:

Jim,

"Udam..."

Wilkey

Click to expand...

LOL! OMG! Exactly.

Ah, I'm glad we can laugh about it, especially you. I suppose that you probably keenly miss having your own chronicler and biographer and personal interpreter here on CPF --who, as it turns out, knew you better than you knew yourself, and --sadly-- turns out to have had a much darker view of your motivations, decisions, and career.

We must all, though, sooner or later bow down before the superior wisdom, and accept the fact that we are ALL loosers for not having made an E2e sized HID light with miniaturized ballast running li-ions and named after a rather attractive young woman. Pathetically, we continue on with such rich mans toys as the M6-R and the Aurora2. Woe is us. Hear us sob.

It seems high time to bump this thread to the top!

A number of people are obviously intereted in a rechargeable solution for their M6's, but are leery of pre-paying for an HD-M6, which has seen repeated delays and whose delivery date is still uncertain. In addition, many would like a "drop-in" solution.

Forgive me, everyone, for not making more M6-R packs, but the amount of work-bench time involved in each one is substantial, and having made 40 of them already, I am not eager to make very many more. I will, possibly, make a few more for a sale, and/or for a CPF benefit auction, but certainly nothing like the numbers needed to supply the demand.

So, until the HD-M6 is field tested and proven and is actually shipping, I would offer this solution posted by kalengkong.

It needs some exploration and testing, however, because the most powerful R123 cells--the Powerizer, and the LightHound R-CR123--will probably hold higher voltage under load than the cells used in kalengkong's case. Or maybe not?

But I would suspect that the MN60, at least, will be viable (and bright!).

Some cautions:

1. Always charge the R123's separately, and check voltages of each individual cell before inserting into MB20 holder to ensure they are all at the same state of charge.

2. Turn off light immediately upon dimming. Do not over-discharge.

3. This is experimental--your lamps may explode or flash at turn on. So if you choose to explore this option, beware. It is barely even proto-typed at this point, to my knowledge. The MN60 is the safer bet than the MN61 explosion-wise/flash-wise.

If there are people who are running R123's and the MN60 or 61 in your SureFire M6's, PLEASE SPEAK UP!

I don't know what the runtimes or outputs of these configurations will be, but the MAJOR advantage of them right now, is that they are availabe (wait for it . . . . .)

RIGHT NOW. (DON'T wait for it!!!!)

Just buy six or seven or eight (spares are good) Powerizer or LightHound R123's and either an MN60 or MN61 (or both), and you are ready to try out your very own rechargeable M6. Nothing to modify or build (or wait for others to mod or build) And be part of field testing and exploration in the grand tradition of CPF at its best--a community effort.

You could also try the N61 or N62 12PM lamps, but their focus is slightly off when used in the M6 head--at least according to what Size15s has said--so the MN60 and MN61 are better choices, beam-wise.

And always remember: Li-ions are potentially DANGEROUS animals. Be aware of proper use and care and potential dangers.

js, how about using the 3.0v rcr123's? I have 6 of these, and when I take them off the charger they read 4.2 volts each but heard they drop down close to 3.0v under load, because they have some kind of regulation circuitry in them.

I have no facts about these cells and make no claim to whether they do opperate at 3 volts under load, but if they do, would they work with the MN20 lamp assembly?

Thanks for bumping this thread also. I had not seen this one before and it seems very promising that I can get some kind of rechargable solution going while I wait ( quite long, as you well know ) for the other rechargable solution to become available.

dizzy,

It's a great idea!

I just know next to nothing about the 3 volt / protected Li-ion cells. Last I checked (some time ago now) there were two main problems with using them to run the M6: the protection circuitry sees the filament as a short circuit and won't let the cells turn on, and the current handling capability is not as good as the unprotected ones.

The MB20 is a 2p3s, ie. two stacks of three series R123's. So to run the MN21 HOLA, each stack would need to deliver about 2.5 amps if the voltage they maintain is about 6.8 or so volts. ie. their discharge curve at 2.5 amps would need to be about 2.3 volts per cell. This is obviously problematic, because if the voltage is THAT low, the cells are sucking pondwater, and the curve will be steep and the output too variable.

So, as you rightly suggest, the MN20 is something to think about. It's drawing about half the current of the MN21, so each stack would need to handle 1.2 amps or so. Entirely do-able I should think. But what about the voltage? Well, if each cell maintains 3 volts, we end up with way too high a voltage (9 volts). The operating voltage of the MN20 is something like 7.6 volts. divide by 3 and you get 2.5 or so. That may be a realistic number for voltage under a 1.2 amp load for a 3 volt R123.

Or maybe not. Does SilverFox have graphs for the 3.0 volt R123's? Or is there a thread that does?

Because the MN20 is already driven pretty hard at 7.6 volts. I doubt it would take anything much over 8 volts.

It's certainly something to look into, though! First thing to do is get a link to discharge graphs of the 3 volt 123's.

As a post-script, I will point out here what I have said elsewhere, and that is that people would be wise to clearly and rationally evaluate whether or not primary 123's wouldn't be a smarter choice than a rechargeable solution.

The M6 with MN20 installed running on primary 123's is one heck of a flashlight. One of my very favorites, FWIW. And you get an hour of runtime from 6 123's. And 400 lumens of output--bright white output, too. The MN20 has a very high CCT for a production light.

So, it's just a suggestion to consider. Nothing more, nothing less. But especially relevant here, where the experiment could mean blowing up a $30 lamp and sullying a very expensive turbo head.

I think I will pass on using the 3.0volt rcr123's in the M6 until I get more facts on them and their safe usage. I would not want to screw up a lamp or a turbo head or both, just to save a couple bucks on primaries.

The use of primaries, though, with the MN20 is sound advice, which I will use. I just resently got an MN20 ( just became available again ), but never really even checked it out yet on fresh cr123's. Is it really putting out 400 lumens?

Thanks again for the information, God knows I can always use the help.

dizzy,

Good plan!

And yes, from all of my testing, I find that it is indeed putting out 400 lumens on fresh cells. And the MN21 is putting out 630 or so.

This is based on comparison with the TigerLight 375 lumen LA, which was tested in an Integrating Sphere, and on the MagCharger-1160, which is putting out 450 lumens based on re-rating forumulas and a bulb-lumens to torch-lumens conversion factor, which was also tested via an integrating sphere.

The issue of just how many lumens something is putting out is a thorny one. Long ago, people noticed that the SureFire lights lumens ratings just weren't commensurate with the lumens ratings from the Welch Allyn website for their lamps. The SF lights were under-rated relative to the WA ratings. Ingenius testing via ceiling bounce tests and light meters, suggested a rough figure to convert one to the other.

And on top of that SF under-rates their lights. For example the SF E2e clocked in at 83 lumens in the Arc Flashlight IS tests. Yet it is only rated at 60.

See bLu vs. tLu: IS confirms 65% conversion factor for more discussion on the subject than any sane person could possibly want to digest in one sitting. Ignoring the in-fighting, and concentrating on the informative parts goes a long way towards making it more palatable.

Anyway, short answer is I call it a "400 lumen" lamp in order to more properly rate it so that the reality fits with the CPF-assigned values. It really is just slightly less bright than a 450 lumen MagCharger running the 1160, and slightly more bright than the TigerLight with the 375 lumen LA installed. So if we accept the one set, we must accept the other.

And the TL HOLA was tested in an IS. I know because I'm the one that sent it to be tested at LSI of Arizona and got back a lumens/MSCP rating.