For those of you that own a Jetbeam BC40, what batteries fit in the light?

ok, I am having trouble finding batteries that fit in this light, so far, i tried button top tenergy’s, those bottom out, they are 69mm. Then i tired some TF 3000mah’s (which i just got yesterday), advertised as under 68mm, but its nearly 70mm , making it even longer, and bottom out worse, might even damage the reverse polarity. before all this i used the dodgy ultrafire 3000mahs, which are the only ones that fit (around 68mm) properly … lol

any ideas? should i use unprotected? what fits? XD

I use Tenergy protected 2600mah cells in my BC40 with no problems at all.I have a pair of Marsfire protected cells that work fine also.I would strongly advise against the use of unprotected cells in series.When you say “bottoming out”, do you mean you can’t screw the tailcap all the way on?If the cap isn’t on all the way the light won’t work anyways(anodized threads).I just checked mine and found that it has a driver and tailcap spring with lots of play for differant battery lengths.

when i mean bottoming out it’s more of a feeling thing. when I use the ultrafires, the original ones I 1st used, the tail cap will screw in with a constant effort till it hits then end of the threads. When I bought the tenergy’s, they went in, and I started tightening the cap, it was good till near the end, when i had to increase the effort quite a bit (last turn or 2) to seat the cap, the even longer TFs need even more effort. it also creates a side effect of making it hard to loosen the head to change modes. It also left spring indentations on the (-) end of the tight fitting batteries

Haven’t found any that don’t work, except the Tenergy cells that I have because they are flat top and the button does not make contact between the 2 cells. The EagleTac 3100s and Keeppower 3100s both work and teh Keeppower are VERY long cells.

Now I understand.I wonder what the diff. could be between our PA40’s could be?I just checked mine and the tailcap goes on smoothly all the way until it is tight.With the cap off and the batteries installed I can move the batteries down about 6-8 mm until they bottom out the driver spring.The tailcap spring goes at least that much also…this should leav a lot of room for diff. sized cells.Which side are you getting tight at, the driver or tailcap?Looking at the tailcap switch it looks like it wouldn’t be too hard to cut a few turns off of the spring.Dents in the batteries is def. not a good thing.

also my driver spring is about 1/2 the compressive strength of the tailcap one, travel is about what you said. i always put in the batteries in thru the tail cap. When i tighten the cap with the tight fit tenergy’s or TF’s it will also make the effort to turn the Head tighter too. maybe its just my light, iono

also pic of the dinged batteries:

For one the difference is he is talking about the BC-40, not the PA40.

My batteries have a small scuff from the tailcap spring but that’s it, you’ve got a dent.Looks like we are using the same batteries so I don’t know what gives(sorry 4 the pun).All I can suggest is to make sure you tailcap switch is screwed all the way down into the tailcap(I doubt thats the problem), or cut some turns off the spring to make space.There must be some tolerance in the length of the battery tube that is making the diff.Dosen’t look like there is much you can do at the head end without damaging the mode switch.What’s the lenth of your battery tube?Mine is about 14.5 cm.

Ya I know….BC40 takes two 18650’s(what we are talking about) and the PA40 takes 4 AA’s, I have both on the table with me.

Oh…and the PA40 dosen’t have a tailcap either, does it!

wow, i just measured my battery tube, its only 14cm even (5.5”), that is a VERY big difference for a light of this quality/brand> maybe they did a modification sometime in its midlife cycle, i bought this light around last October

edit: I just checked selfbuilt’s review over at CPF, he measured his bc40 sample at 224mm (22.4cm), mine is about 222mm and based on pictures he has I can physically see that its shorter by the flat area next to the tailcap end.

I don’t know….I think I got mine this past june mabey?Mine is a NW that I got from Shiningbeam but that shouldn’t make a diff.Either way…5mm shouldn’t be enough to cause this though.The springs should be able to make up for that, I would think?Does anyone else care to measure the battery tube on their BC40 and see where it fall between 14 and 14.5cm?

actually 5mm will be a big difference, if i had an extra 5mm, all my batteries will fit. my longest cell and shortest is a about 2mm difference. so X2 will be 4mm, which means if i had 5mm more, they will fit, plus some

i also have a NW

My recent purchase is also a NW and the tube is only 14cm. But I have no trouble putting my tenergy’s in. By the way, the o-ring makes it harder to turn the last 2 turns too.

the tightening happens after it passes the initial o ring tightening. when i use the UF, it does not tighten more, when i use the tenergy, the effort increases x2-3 after the initial o ring seat tightening as it nears seating the tailcap completely

You’re right, the BC40 doesn’t like the longer cells. Of all the protected batteries I own, I only managed to use the “Trustfire ”flames” protected 18650’s with no problem.

Hope this helps…

funny thing is I nearly bought those 3 weeks ago, but instead op’ed for the 3000mah flames :bigsmile: hmm maybe i need to buy the 2400mah after all, lol. i guess i cannot trust manafont measurements, or they have gotten longer since they last measured them

Perhaps you can try one flat top and one button top tenergy, that is what I do.

i considered trying that actually, since my tenergy has only been thru like 1 or 2 cycles, I can buy a flat top version of the 2600 and make it fit, but still i am not sure if using a button top and flat top together is safe, lol