17500's not working in SF M3

[Porter]

I ordered 2 AW 17500 batteries, an Ultrafire multi battery charger, a Lumens Factory EO-M3 extreme output lamp assembly and a recommended 1.6mm magnetic spacer for my Surefire M3 from Lighthound. After charging the batteries they registered just over 4 volts after taking them out and resting them overnight. I just can't seem get these batteries to work in my M3. Both the stock MN10 bulb and the EO-M3 bulb work fine with CR123 primaries but neither work with the 17500's. Lighthound has really been great communicating with me via email suggesting possible fixes. He even tried this setup on his own flashlight and had no problems. This is where I am at: I install the 2 17500's in the flashlight and leave the tailcap off. If I bridge a piece of metal;aluminum foil, paper clip, metal ball point pen between the battery and the inside of the flashlight it works

! I am still working with Lighthound on this but I was just wondering if anyone here had any ideas as to what might be the problem? Thank you for any possible suggestions.

 

[mdocod]

hmmmmmmmmmmmmmmm, very curious...

have you tried going back to the CR123s since trying the 17500s... it should work fine, especially if it works fine by bypassing the switch with a wire...

My guess is that something is wrong with the switch itself?

[edit in]
I don't think you need any magnetic spacer for the AW 17500s, they have built in nipples and shouldn't need any extra help making contact.. I haven't heard of needing anything like that....

 

[Porter]

Yes. The CR123's work fine with both lamp assemblies. What's even more curious is I installed a stock 6p tailcap on the M3 and it worked fine with the primaries but not with the 17500's. I'm pulling my hair out trying figure this out. Thanks for the response mdoc.

Edit: Oh, it doesn't seem to matter whether I use the spacer or not, the results are always the same. CR123's + either lamp assembly + either tailcap switch=success.17500's+either lamp assembly + either tailcap switch=failure

 

[cfromc]

Have you tried putting the magnet on the end of the cell where it contacts the tail switch spring? Just curious to see what happens (if anything).

 

[Porter]

Thanks for the response cfromc. Yes, I tried that but no dice. lining up the batteries next to each other, the 2 17500's are almost the exact same length of 3 123's. The 17500's might even be a c-hair longer. So I think mdocod is correct, there really shouldn't be a need for the spacer.

 

[9x23]

Is it possible that your tailcap's metal ring inside isn't making contact with the end of the battery tube due to the batteries being ever so slightly longer than primaries? I've run into this problem before in some lego configurations of surefires using rechargeables, but can't remember exactly what.

9x23

 

[Supernam]

I know what's wrong (hopefully)!!! The width of the top end of the battery is slightly wide and will push the outer spring of the lamp assembly upward causing the spring to lose contact with the body when loaded up. What you need to do is bend the outer spring of the lamp assembly so that it is wider. Hold the cell against the lamp assembly, the cell should be able to slip inside of the of the outer spring just slightly.

This was what happened with my L6 on the same cells. I noticed that my light would flicker when the light was shaken. I knew it had to do with the light maintaining contact with battery, body, and head.

 

[Porter]

Thanks 9x23. That could very well be the problem. I think I've narrowed it down to a mis connection between the M3 tail cap and the 17500 battery.
Any suggestions on how to adjust the spring in the tail cap? Or maybe I need to disassemble the tail cap altogether?

 

[adamlau]

Two AW Protected 18500 cells fire up the MN20 in my bored M3 w/o the issue you are describing.

 

[Porter]

I've sat here and pulled and pushed on that spring for the last 25 minutes using a lot of strength (boy that is one heavy duty spring) and you were right on target. after looking at it closely the 17500 is indeed just a c-hair wider on the very top than the CR123. Supernam you truly are a superman. I am eternily grateful. Thank you.:bow:

 

[Fusion_m8]

I have the exact same problem... my KT4 works with both AW & Ultrafire 17500s, however when I switch over to the KL6, only the AW work, not the Ultrafire. After investigation, it appears that the negative spring in the KL6 is a little skewed and not making good contact with the body, so the Ultrafire 17500s need to be fiddled around A LOT to allow the negative spring to make good contact with the body. No such issues with AW 17500 which are slightly thinner in diameter by about 0.5mm.

 

[Bullzeyebill]

This happens to my M3 when I use 17500's, protected. They are too long and two of them push the outer spring away from contact with the head of the battery tube. I switched to 18490's (my body is bored) and being shorter than two 17500's the light now lights up just fine. When you compare how high the end battery sit,s first using 3 CR123's, then trying out 17500's the 17500 are very close to the top of the battery tube. When I use the 18490's the end battery sits lower at about same depth as 3 CR123's. Just an overall length matter. Need shorter LiIon's, for example unprotected 17500 (actually 17490's). I know some people are afraid of unproteced LiIon's, but it is the only way I can run my M3.

Bill