26800 Lithium-ion battery

I’m seeing those two points also. I paid $59.27 for 8 Mooch tested QB26800’s, half the amount for untested K64’s. But they need a custom tube. Most of the listed lights operate under 15 amps. Except 7 LED MF01 mini, and FT02S that’ll need all the amps a battery can push. Future lights like Astrolux EA01S will definitely want the highest. I’m looking for both runtime and output. It’s QB26800 for me, I’ll gladly pay extra for the extra tube.

Hummm,
I clearly need a lathe. The tooling. Someone to show me how to use it. And a place to put it.
Other than that, I’m ready……

Done it on the drill press… made an arbor out of thread all nuts and a socket with a diameter close to what I needed… use a rotary file, tootsie roll, or sanding drum to open up the I.D. of the copper ring with about ,003 stock press fit to the O.D. of the socket arbor, press the copper rings on using the next size up socket which so happened to also fit the arbor nut…you can use any material to space the front of the tube out… the battery tube threads are bare…………………………………………………………………………………………… :wink:

Here are more pics…of the mod…

EDIT: Instead of using 2 rings to extend the bat tube at the front…(head)…I’m using one in the front and one in the cap… yes you do have to open up the I.D. of the driver retainer ring also…

215Wh/kg and 600Wh/L is pretty low, especially since that’s only at 1.36A discharge.
And the more current you draw, those numbers drop to significantly less.
A high capacity 18650 or 21700 can do much better specific energy and energy density at higher currents.


Those of us going with single cell lights this cell tops in capacity with practical output. I also have lights in 18650, 21700 and several other sizes. I think you may have missed the flavor of this thread and that is to take something different and run with it. In this case the 26650 lights and how to incorporate a 15mm longer and better battery.

That long and thin back spring looks like it could add a lot of resistance and drop a lot of voltage under load at 20amps. You might get more output with a bypass or shorter spring

This is far from the highest capacity single cell.
There are plenty of other sizes above 26650, such as 38120, 38140, 40120, 42120, 40152, 66160, etc etc etc
Those can get to 10Ah-40Ah+

Might as well use something better than 6800mAh if you have to custom make your flashlight anyways to fit a new cell size.

I’m sorry, I did not mean to offend you and set you on this path.

KB, thanks! Those bigger cells definitely require custom fabrication, but with the 26800, KB did something relatively simple with a common light, the FT03, and I got quite a few 26650/26700 lights that may be capable of being extended similarly.

Not sure if you fabricated all those copper rings, or had some that just had to be machined down. I can't follow all of it because I don't understand all the lingo but I get the end result for sure now.

26mm Copper Crush Washer’s… the finished O.D. ended up being 29.8mm and the I.D. being 27.3mm for them to drop into the head on my FT03… made the driver contact out of .020” copper sheet and used my Precision Brand Shim punch…

I never looked to closely but I’ve had the same impression.

And cell availability aside, there is a 26800 light out there. Modding a 26650 one is easier than fitting a larger cell.

For the FT03, I'll probably try copper single strand wire first for the spacers, but still do the driver retaining ring mod and swapping out the driver spring - I'll probably use a low profile brass button.

26 mm to 29.8 mm is a big bump - not sure if that was why you used the sockets? Didn't understand that part. the 26mm washers I can only find for $10-$12 for qty 6-10.

Think'n to order another HK4S SST-40 and swap in XHP50.2 3V's - should be a nice use of the big cell.

$46 at FT here: https://www.fasttech.com/products/1601/10073177/9738130, just posted today here: https://budgetlightforum.com/t/-/37772/1008

Update: Ordered one from FT - $46 total shipped, same price I paid for the first HK4S on coupon discount from BG.

I received 8 QB26800 batteries from Aloft Hobbies a few days ago and cycled one of the cells along with a new Shockli. Recharged two batteries after both drained from a HaikeLite HK4S which has a 2.72 volt cut off. An Xtar X2 charger is used for the test. First battery the Shockli 5500 mah and the second was the QB26800. Shockli charged 5715 mah, QB26800 charged 7330 mah. Both batteries are on their 3rd recharge. Shockli is very close to an earlier test within 12 mah. This latter batch of 26800 went up 206 mah.

If you guys are still interested.

Signed up for everything. Good to hear about Amutorch and Nightwatch - that e-switch version of the Ni40 Stalker looks amaz'n!

Good job. Thank you freeme!

Ama-zoning a few nights ago and ran across the Alonefire X28 (I know, but their UV lights I have found to be a good value so I decided what the heck) that comes with a 26800 cell.

Humble delivery - light, cell and USB-C cable (that didn’t function) - no instructions or spare o-rings or anything.

SST40 (?) emitter with smooth reflector.

Light works. UI is Hi-Lo-Off. Double click for strobe. OK, quite crappy UI.

Throws a nice tight spot with pretty broad, dim spill. Says SST40 but much cooler than my FT03 SST-40. Maybe a just a bit less bright than FT03 at center of hotspot but tint difference makes it kind of hard to compare. Haven’t had them both outside yet.

Doesn’t feel like an expensive light, but other than the bad cable it seems to work fine and only $18 is why I was tempted.

We’ll see about longevity.

Posted here just because of 26800 discussion - maybe a good host and get a decent cell to boot?

Dang, it's listed for $28 now w/10% coupon. I would have bought one for $18 for sure. It appears to be about a 45 mm head diam.

Here on Alibaba it lists the head diam at 45 - had a pretty good guess

Is that a real SS bezel?

I grabbed one off of Amazon Prime for $18. It’s CR@P. I thought for $18 maybe the threads would match some of my other lights. Compatible with none of them. Threads are rough with slivers left in. Bezel is Aluminum. Reflector gives a ringy beam profile. For the price I got a 26800 battery and a power cord.

Ohhh. One sign of a cheap light is that white plastic/brass setup in the tailcap. Thought maybe it's just the tailcap, but guess the whole thing is at that level.