Do any 18340 cells (or similar) exist?

[2xTrinity]

I presently have several flashlights that accept either 1x18650, or 2x16340 (rechargeable CR123). Most of them are dimmer, but have longer runtime on 18650. 2xCR123 offers better regulation and higher brightness, but unfortunately, those cells simply don't have as much energy capacity as the 18xxx variety. I'd love to buy some 18340s though that would be thicker (and thus have greater capacity) but still fit in the same tubes which have been bored out for use with 18650. Is there anything like this out there?

 

[VidPro]

there exists a 18500 readily available, can you cut some spring off 🙂

 

[2xTrinity]

there exists a 18500 readily available, can you cut some spring off 🙂

Well, I'm going for something that will be only marginally longer than a protected 18650. Unfortunately there's probably not much of a market for that form factor, I was just hoping I might get somewhat lucky and find a product in that form factor (similar length to CR123, but fatter). A flashlight with a 2x18500 tube would be nice though -- that size is still quite a reasonable size of a handle, wheras 2x18650 is awkwardly long, especailly when coupled to a ridiculously huge head like seen on some incandescent flashlights.

It looks like the best combination of a light with good battery capacity, while still maintaining a comfortable size is probably 2 "C" LiIon. Using a couple of those in a modified 2C flashlight to drive a Seoul or high-binned Cree at maximum power, with good regulation (using a buck circuit) AND good runtime is something I may look into doing in the future, though it's a bit too expensive/ambitious for me right now (between the cost of drivers, cells, yet another charger etc.), that's why i'm looking for something that will work out of the box with what I already have.

 

[DM51]

A fat 34mm Li-Ion cell would be a great idea. If you compare 18650 vs 17670 capacities, (2200mAH vs 1500mAH), it would suggest that you might see ~50% increase in capacity over RCR123 with the extra diameter. An 18340 could be ~1100mAH. I doubt I am the only person who would find a good use for that (for example, you could run an EO-9 safely off 2 of them in a WE Sniper). Something for AW to think about?

 

[FlashKat]

I am looking for the same thing.
The closest I have found is the link below, but I don't know how good these are plus I am looking for 3.7v, and not 3.0v batteries.
http://www.qualitychinagoods.com/17335-1000mah-rechargeable-p-516.html

 

[Curious_character]

I am looking for the same thing.
The closest I have found is the link below, but I don't know how good these are plus I am looking for 3.7v, and not 3.0v batteries.
http://www.qualitychinagoods.com/17335-1000mah-rechargeable-p-516.html

Those look like standard CR123A size cells. I do like their honesty, though, in warning us that the capacity isn't really what's claimed. That's true of most batteries, but it's refreshing to have a seller come right out and say it.

c_c

 

[DM51]

I am looking for the same thing.
The closest I have found is the link below, but I don't know how good these are plus I am looking for 3.7v, and not 3.0v batteries.
http://www.qualitychinagoods.com/17335-1000mah-rechargeable-p-516.html

Very interesting link, FlashKat - thanks.


It is a 17335, so 17mm diameter not 18mm. It claims 1000mAH capacity, but with a big disclaimer on that. Let’s say it is more like ~900mAH. That is still 150mAH more than a 16340 (RCR123). So the 1mm diameter makes a significant difference (we already know that anyway, from 18650 vs. 17670)



However it looks like it may be an unprotected cell (and QCG’s blurb says “be careful” etc). I may be 100% wrong - I don't know anything about 3v rechargeables as I don't have any (all mine are 3.7v).



A protection circuit would add ~2mm to the length, or you would have to make the bare cell 2mm shorter to allow for the PCB; but still, on this basis an 18340, with an extra 1mm diameter, would surely give at least 1000mAH, maybe more.



Bring it on, AW!

 

[DM51]

Sorry for any confusion re above post #7 - the [/quote] handle doesn't seem to be working properly and when I try to edit it the program hangs on me. I hope it's reasonably clear which bit is FlashKat's quote and where my reply starts.

EDIT: Disregard - post #7 now fixed.