Sold/Expired Interest Thread: 2x18650 battery adapter for SureFire M6

UPDATE 8-8-08!
The adapter has been finalized, the sales thread can be found here:
https://www.candlepowerforums.com/posts/2585641#post2585641
Any further discussion should be continued there.

Thank You,
Eric

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Been messing around with this idea for awhile and decided to do a little cutting and drilling yesterday.... here's a prototype. (updated prototype 5-5-08)

Only problem is.. I'm a pizza deliver driver, which means an M6 isn't something I can justifiably own on my budget, lol...

So... if you are an M6 owner who has 2 working 18650 cells (one of mine is dead, for some reason) who would like to help out by testing this, say so in this thread, first to respond who meets requirements gets it!, reward will be in the form of a free adapter. oh yea...test candidate must live in the U.S. (easier/cheaper communication, faster mailing, etc etc)... All I need the tester to do is see if things fit, see if things line up, and make a few suggestions to improve the design based on actually having an M6 in front of them with the adapter, having a few bulbs available to test the adapter with wouldn't hurt, but the standard MN20 will do fine.

Prototype tester found!, Thanks JetSkiMark!

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Here's some of the obvious and maybe less obvious configurations that could be done with this adapter:

2x protected AW/Pila/Wolf-Eyes 18650 LiCo02 cells driving lamps designed for the M3T:
SF MN15 or MN16, or LF HO-M3T or EO-M3T.

2x protected AW/Pila/Wolf-Eyes 18650 LiCo02 cells driving the SF MN20 for extended bulb life compared to M3T bulbs.

2x unprotected quality cells (LG) used responsibly driving a MN21. (this isn't totally safe, experienced Li-Ion users only!)

OR... (not sure if anyone had thought of this yet)
A pair of the 18650 size lithium manganeze oxide cells. Sold by Emoli, and often found in power tools (I have seem the in the new Ryobi Li-Ion kits) driving a MN21.

OR....
A pair of 18650 size Lithium Nano iron Phosphate cells, (A123 systems, found in black and decker VXP system) or alternatively, a pair of lithium iron phosphate cells form online somewhere provided they are rated for high current. This would require purchase of more specialized charger. (~3.6-3.8V peak charging)... I think this could be used to drive a 5761 in a FM MN bi-pin tower.... (provided the bulb fits through the reflector hole?)...


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If you are interested in this adapter for your M6 (or COLLECTION of M6s, I know there are a few of you ), let me know in this thread.


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Oh forgot to mention, the prototype pictured above is made from 1.25" diameter end caps, the final version would probably be made form 1.375" end caps to come closer to "filling out" the M6 body.

Re: Interest thread: 2x18650 adapter for M6, prototype tester requested.

I'll be your prototype tester.

I have AW's protected 18650s and an MN20. I have a used MN to bi-pin adapter on the way and a WA1111 to test it with.

Regards,
Mark

Re: Interest thread: 2x18650 adapter for M6, prototype tester requested.

JetskiMark!
Awesome, that was fast! lol...

I'll PM you with more details in the coming days... I'm going to make another variation or 2 on the prototype that just came to mind before testing

Thanks,
Eric

Re: Interest thread: 2x18650 adapter for M6, prototype tester requested.

Eric..just a heads up. I've been playing around with 18650 Emoli and A123 cells, although not in an M6.

Both of them are shorter than AW and Ultrafire 18650 cells. Not a lot, but enough to require some sort of spacer.

Re: Interest thread: 2x18650 adapter for M6, prototype tester requested.

I just put two 18650s in my M6 and the I.D. of the body accommodates them with a little room to spare. It's unfortunate that three 18650s will not fit.

I had tried two fully charged 17670s in my M4 with the MN20 and it was not very bright or white. It will be interesting to see how the MN20 looks with two 18650s. With an adapter, the 1111 will probably be nice.

I'm looking forward to trying out the various combinations.

Regards,
Mark

Re: Interest thread: 2x18650 adapter for M6, prototype tester requested.

donn_ said:

Eric..just a heads up. I've been playing around with 18650 Emoli and A123 cells, although not in an M6.

Both of them are shorter than AW and Ultrafire 18650 cells. Not a lot, but enough to require some sort of spacer.

Click to expand...

Thank you for the heads up donn!
However, this will not be a problem, the adapter is adjustable and should accommodate any cell length from ~60mm-70mm.

Eric

Re: Interest thread: 2x18650 adapter for M6, prototype tester requested.

Looks good, Eric! Looking forward to the final version!

Re: Interest thread: 2x18650 adapter for M6, prototype tester requested.

The WA 1111 with the FM MN bi-pin holder will be a very good option. It is almost indistinguishable from the MN21/primaries in performance, and with 2x 18650 like this it will have ~2x the run-time.

The Philips 5761 will not fit through the reflector hole.

I think if you try to use an MN21 with 2x 18650, the bulb won't last long.

At ~2.5C, the MN21 should only be used in bursts of <1 min, so Emolis would be better, but bulb-life will still be the problem in either case.

Re: Interest thread: 2x18650 adapter for M6, prototype tester requested.

This has been tested and used with success by CPF´r CM before. Kind of like the bored out M4-MN21.

Re: Interest thread: 2x18650 adapter for M6, prototype tester requested.

Hello DM51!

On regular li-ion cells (LiCo02) the MN21 will be fine. The standard pack sags to around 6.6-6.75V, A pair of Li-Ion cells, even unprotected LG 2400s will never hold better than ~7.4V into that load, and that's only for a short time, they sag to ~3.5V and under per cell through most of the discharge at 5A. Which is pretty similar to the discharge that can be expected from the standard pack of CR123s. The trick to such a setup is to re-evaluate the condition of the cells being used every few cycles. I do not suggest such a configuration if you plan to be using it heavily and daily and need something dependable and safe, it's a toy when you drive the MN21 on 18650s.

The Emoli's on the other hand, would present a bulb life problem for an MN21 as they have substantially lower resistance. [edit in] An NTC might help, hard to say. I can say that an NTC would be remarkably easy to install on this adapter, since their has to be a wire running from the head of one cell to the tail of another

Eric

Re: Interest thread: 2x18650 adapter for M6, prototype tester requested.

Wassup, mdoc!

Thanks for the info on the voltage sag with 18650s. 5A would be thrashing the 18650s quite heavily, so as you say, not good for them.

Using an NTC stops 5761s instaflashing with Emolis, so it could work well with the MN21 too - good idea. And as you say, there's plenty of room to install it next to the cells.

You'd probably get ~1,000 lm out of it, compared to ~800 lm from a WA1111, but short-ish run-time.

Re: Interest thread: 2x18650 adapter for M6, prototype tester requested.

UPDATE: waiting on some materials to come in, supposed to be here by sometime next week. I want to build another prototype or 2, send em over to JetSkiMark and hopefully have a final version figured out by the end of the month of May.

Eric

Re: Interest thread: 2x18650 adapter for M6, prototype tester requested.

materials came in and I just finished this prototype (pictures in OP have been swapped for the new design, I like this a lot better, end caps are 1-3/8" dia, makes room for the support rods that help line up the cells.

To load, you slide the cells in from the side, both facing up, center them, clasp the whole thing, and snug down the nuts on the top.

JetSkiMark... I'll be sending a PM shortly

Hello mdocod,

I am going to order two of your 6AA adapters and one 9AA. This should help cover the cost of this prototype. I will post in your sales thread and send a cash PayPal.

Regards,
Mark

hehe... you don't have to cover the cost of anything, you're helping me out But I'll never argue with selling an adapter!

Thanks!
Eric

One hand washes the other.

Regards,
Mark

interesting looking adapter... could you make one to fit 3x 17670?

would need to be identical in size to stock M6 battery pack.

Good idea here. For the record, I have been running the MN21 powered off IMR18650E cells in a bored M4 for a couple of months now. Have drained down the pair of 1400 mAh cells a few times, runtime appears to be about the same as that of the MN21 off 6xCR123A. The MN21 off Moli cells is my most heavily used setup by far. Looking forwards to these adapters .

adamlau
Thank you for the info on the Emoli cells on the MN21, my gut had been telling me this should work fine, you have confirmed this!, Thanks!

Hello Eric,

I received my order and prototype today. Thank you.

The prototype is too long. The MB20 is 93mm x 37mm. I measured the prototype at 108mm x 35mm. The diameter is fine, but 2mm larger would be better. I was not able to screw the tailcap switch on at all to see if the adapter would rattle. Maybe the end caps could be a little thinner and the contacts could be recessed into them a bit.



In the picture, I lined up the ends exactly even with the ruler. You can't tell from the angle that I took it from though.

The tailcap switch has a spring that ends in a small diameter, about 4mm. This needs to mate to a flat contact. The dome of an acorn nut would deflect it to the side.

The large washer on the end could short out to ground. I think you could use a plastic washer or drill the end cap holes only half way to capture the alignment rods.

I think that once this adapter is finalized that it will be popular. I agree with Adam. With 2 IMR18650E cells and the MN21, this would be a nice rechargeable combination.

Regards,
Mark