I wanted to ask if anyone knows the max length (mm) 18650 battery you can fit in the various Convoy models.
I’m researching and shopping for some protected batteries and want to make sure I don’t buy something that won’t
fit. Thanks.
S2+ max battery length?
S3 max battery length?
C8 max battery length?
M1 max battery length?
M2 max battery length?
Stock C8 with a 105C, can’t really say, but I have a genuine C8 host that I’ve fit with a 105C will fit a Panny NCR-B just fine (one of the longer protected cells at ~70mm).
Got drivers that are just flat discs on the battery side (ie, no springs) that I can fit even more easily with the button-top Panny.
I am sitting here with a protected Keeppower 3500 mAh. I just measured it to about 18.6 mm in diameter and 69 mm long. I purchased the following Convoy lights a month ago, which arrived last week. Here is how they fit the Keeppower 3500 mAh
Convoy S2+ Green: Perfect rattle-free fit.
Convoy S2+ black UV: Very tight fit, the cell is too thick. Can be mashed in there, but it will wear out the protective plastic around the 18650 cell eventually.
Convoy M1 Black: Perfect fit, even sligtly rattles.
Convoy C8 XPL-HI Black: Cell is way too thick, and I don’t think I would be able to mash it down there.
However I also purchased a EagleTac 3400 mAh (green and white). This measures about 18.3 mm in diameter and and about 68 mm in length. This easily fits in all of the convoy models that I own. So it appears that it is especially the thickness of protected cells which may cause you issues. The EagleTac 3400 mAh is probably one of the thinnest and shortest protected cells you can aquire, and should fit Convoy models according to my testing. However the protective plastic is rather brittle, and the discharge characteristics is not as favorable as the Keeppower 3500 mAh.
Length from tube top to tailswitch retaining ring:
S2-69.7mm
S2+–68.8mm
C8-70.5mm
M1-71.7mm
M2-71.5mm
Sounds like some Convoy lights need to be bored wider to fit protected 3500mAh NCR18650GA cells in future batches.
Easy solution, just buy batteries like the Samsung 25R or 30Q. You’ll have no issues or problems then.
You really don’t ‘need’ protected batteries. — If you disagree, I highly recommend you spend some time reading up and learning about the different battery types. 
+1
I’ve built a couple of S2+ lights for other people, and usually provide those with protected Samsung ICR 2600mAh cells from Mtn, and those are a tight fit length-wise. The tailcap will thread on, but just barely.
http://www.mtnelectronics.com/index.php?route=product/product&product_id=599&search=samsung+icr+18650+2600
My Convoy S2 will fit anything I’ve tried, including my longer-than-normal Sanyo protected cells. My S3 and S6 hosts are both setup as triples though, and may not be a good comparison as they have custom-fit spacers that may change the space available for cells.
Whilst many BLFers may be comfortable with unprotected, many other potential purchasers of flashlights are not. Thus there is no reason why Convoy should not bore their lights to accept the now commonly found Panny GA based protected cells.
…and I’ve built several lights for other users who may not have fully grasped the potential dangers of Lithium chemistry. In these cases, I want the extra protection in case they don’t pay attention to my warnings when I give them the light.
For my single-cell lights, I use MOSTLY unprotected, except for one I have the needs the extra length of the protected cell to get a solid connection. Otherwise, it blinks or changes mode if it gets jarred.
Hi all,
After enjoing with the “normal” convoy s2+,
i purchased the tube that is necessary to adapt the convoy with the batteries 18350 (top button) so that the flashlight become smaller…
Everything was fine also with the adapter tube, but unfortunately after change to the original battery 18650 (flat button), the flashlight doesn’t work … Seems that the battery do not fit perfectly, and so only if I unscrew the upper part sometimes there is contact and flashlight works… but if I completely screw the tube do not works…
I noticed that the spring of the upper part of flashlight, seems flattered and lowered after using the 18350 battery…may be is this the problem?
Someone can help me ?
Thanks
Alex
attached some photos
