Lumapower M1 Cree -- no light with 18650?

[Dobbler]

I have four protected 18650 batteries from AW. All four work in my Ultrafire C2.

None of them work in my new Lumapower M1 Cree.

With two CR123 lithium primaries the M1 works fine (although there's not much difference between low and high IMO).

So.... what the heck is going on here?

 

[AlexGT]

LOL that happened to me too! put the gold plated screw in the hole in the back of the light module and it will work!

AlexGT

 

[Dobbler]

How deep is that screw? Is this a length issue with the battery then?

 

[riffraff]

How deep is that screw? Is this a length issue with the battery then?

Does your 18650 have a nipple on the anode end?

 

[Dobbler]

I have the magnetic nipple attached to the + terminal. I've stacked as many as 4 on there.

The battery isn't much shorter (if at all) than two CR123's stacked on top of each other.

I'm thinking this is a bad unit that will not run on < 6v?

 

[Dobbler]

So it's strange -- now I can get them to come on intermittently depending on how hard (soft) I screw down the head. Weird. I wonder if this is a shorting issue with the board and pressure causes problems?

 

[2xTrinity]

I have a LP M1, I pretty much exclusively run it on 18650 just using one thin magnet, I didn't attach the screw (as I want to be able to throw primary CR123s in when I want to without fiddling with the screw). It's slightly dimmer on high, but the thing that I like about it is that its low is actually low and runs for a very, very long time. Runtime is also quite decent on high, which has repsectable output.

 

[Dobbler]

OK -- here's what I think is REALLY happening. The 18650 with the little magnetic nipple is a HAIR longer than 2 CR123's. This puts a teeny tiny bit more pressure on the light module, which the presses a teeny tiny bit more against the OP reflector. This causes the light to turn off (shorting?) By loosening the front cap/lens holder a mere 1/4 turn, the light seems to work just fine.

 

[riffraff]

After this thread, I opened my new M1 CREE "Tactical" and...there's no screw. The center part that's threaded for a screw on the older models is now smooth. Instead of having to fiddle with the screw, that center part is now spring loaded, so in theory, either battery type should work without alteration.

Those Chinese...they're so clever! :wow: