Fenix tk11 tight battery tube? Just purchased 2017 ( I know)

Hill all, I’ve just purchased a fenix tk11 (r5). I know, very out of date now, but I haven’t had a fenix before and noticed this one on amazon for £39.00. Couldn’t resist, I thought what a nice looking design for a tactical light, simple interface and I bet it’s as tough as buggery. And if I like it, maybe I’ll buy a newer fenix later. I do like it, yes I’ve got newer torches from olight and thrunite with over a 1000 lumens but I like the simplicity of this. A nice protruding forward clicky, and a slight head twist to change between high and low. 258 lumens with this beam in the real world is plenty bright out to 100m.my only niggle is the battery tube being tight, I’ve got a few different protected 18650s and they’re all tight, broken the wrapper on 1 and started to on another. To get a battery out, I have to remove the tailcap and head so I can push it out. My question…. would the likes of an efest 3500 mah IMr be a better fit and would flat top be OK? The instructions do say to use protected 18650 though? I’ve never messed with unprotected. Many thanks if you’ve had any experience with this issue.

I can do some measurements on a few batteries I have later on if you like? Efest and Sony vtc5 unprotected and I have some protected I got with an Odepro flashlight.
The wrap may be thicker to protect the protection circuitry strip or they could be rewraps.

I have the same problem with my convoy L6 …… remove the tube and push the cells out with a pen .

Yes please that would be helpful, the protected battery that the wrapper broke on was an olight 2600 mah. Samsung icr underneath. Without the wrapper it goes in and out nicely but the bottom circuit is loose and with the tailcap tightened fully in it won’t switch off. I’m tempted to remove the circuit but I’ve heard that icr unprotected can be dangerous. A bit of sellotape to secure the bottom circuit sorts the switching but then is tight up the tube again. Imy assuming if to use unprotected then imr or inr would be the way to go?

Hey how are you?

According to HKJ: Test/Review of Efest IMR18650 3500mAh (Purple) 2016 | Candle Power Flashlight Forum
It seems Efest might be using different cells for their 3500 mAh variant. Therefore I think it’s difficult to pinpoint what the exact diameter of the 3500 variant is. I also don’t like Efest for this reason; too many reviews showing variation in capacity (=different cells).

I also have the TK11 R5, and checked which batteries I have slide in and out easily.

Protected cells

Ultrafire 2400 => yes
Cytac 2400 => yes
Lustefire Sanyo 2600 => no
Generic Sanyo 2600 => yes
Xtar 3400 (NCR18650B) => no

Unprotected cells

Sanyo 2600 flattop => yes (works as well)
Sanyo GA button top => yes
Samsung 30Q button top => yes

So personally I wouldn’t go for the Efest. You might want to check out older 2400 mAh protected cells; these seem thinner than modern 3400 or 3500 mAh cells. Hope this helps.
Cheers :wink:

Edit:

I don’t know if the TK11 has low voltage protection…

That’s brilliant thanks, I’ll check out some of those cells and see if I can purchase one of those that fit. It’s annoying that they all have to vary so much. I usually like to opt for high mah but I’d rather not have to be removing the head unit every time. What’s your thoughts on the tk11, guess it’s something you’ve owned for a long while? How’s it held up? Thanks.

I got rid of my TK11 when I registered here long ago because of the exposed tail switch button. Kept activating in all of my pockets. It was advertised as 285 lumens, but it was more like 237, I think. It’s really made for CR123s, although I used my mine with rechargeable Tenergy RCR123s without any issue. Great quality light, just wasn’t designed with a switch that could avoid accidental activation, which, for me, is a fatal flaw. If you use a Sanyo 2600 flat-top, it should fit fine.

18650s are not meant for consumer use, so there is no (absolute) standardisation when it comes to dimensions like alkaline AAs for example. I do believe modern cells are a tad thicker, so these become a problem with older lights. The Xtars I have were bought for my Thrunite Catapult V3, but I had to remove the sticker to make them fit in the light.
The 2400 mAh batteries from Ultrafire and Cytac use an unknown cell (I think), meaning they’re not using a quality Panasonic or Sony cell. These batteries are generally not recommended these days, however they do fit unlike modern batteries (apparently). The ampdraw of the TK11 is also very low, and since it’s a single cell light, I certainly would not be worried.
I have measured the inner diameter of the TK11’s tube, and it’s 18.5mm, so you can use this to check whether a battery is going to fit or not.

The TK11 was my first and only single 18650 light that I have. I have two pieces though; one with smooth, and another with orange peel reflector. I haven’t bumped into another single 18650 light that I wanted; either I go larger with a 2x18650 light, or I go smaller with a single or double AA light.
Although it’s an old light with outdated specs, its output is still sufficient for most tasks. I do love the simple UI; head tight for high, and head loose for low output. I haven’t used my two TK11s a lot, but I never had problems with them. Back then these lights (starting with the TK10) were known as tanks; maybe the TK series stood for tanks, I don’t know for sure… Well I hope you can find some old school batteries, and if you have more questions let me know. Cheers. :slight_smile:

In that period, Fenix used “Fenix lumens” so to speak. When Fenix switched to ANSI, all their lights’ output were corrected (=lowered). It’s possible that 285 lumens referred to Fenix lumens, whereas the 237 lumens refers to the new ANSI lumens. I remember that the LD20 went from about 200 (Fenix) lumens to about 180 (ANSI) lumens.