26800 Lithium-ion battery

For the FT03, making those copper rings (or ring) as a spacer, probably fitted under the brass driver retaining ring, is probably not an option with the tools/supplies/skills I have. I could though perhaps use copper wire formed in a loop. As long as the spacer is conductive and relatively even thickness, and doesn't interfere with inserting the battery, should work.

Took some measurements on my SP70.
Even with the springs really squished, and the threads not fully engaged, noway are a pair of 800s going to fit.
Looks like the tube needs another 23-25mm or so for a comfy fit.
All the Best,
Jeff

If that new 26650 6400 mah Vapcell pans this mod doesn’t gain much.

Yep, I ordered a pair of the K64's from Ali. They went up in price from $20 for 2, to $25 for 2, plus tax, plus shipping.

For me in NY, that would be about $29 for a pair. The 26800's cost me $17.35 for a pair from Aloft - big difference.

Plus I got a Reese's Peanut Butter Cup in the box . Ok, a little weird but it tasted good...

Texas shooter asked about a 26800 extension tube for Astrolux in Fins sales thread. Fin said he submitted the request to Astrolux, but I doubt it will materialize without a lot of requests from others. Artiet59 mentioned, “All astrolux models / tubes you mention do work together, but ft03 unfortunately does not. Ive tried…” That’s too bad since I need several for my fleet of FT03 lights. Maybe they will make 2 versions. It shouldn’t be too much effort for them to produce them.

For those who need a copper contact disk, they can be found at esty.com in all sizes.

I’ll be surprised if those will compete with the QB26800 above 20A sustained, but I’ve been surprised before. Im looking forward to your impressions and hope for the best.

true - the QB26800 is rated at 30A continuous, the K64 is rated at 15A continuous.

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.