Please note a double-click from OFF goes direct to turbo, so from OFF, it can go directly to low or directly to turbo. I find the OFF to turbo very useful.
I saw that earlier on the threads and very much appreciate it. I did not know that from playing with it. Great feature.
Another nice feature of it, is that from turbo, 1 click returns to previous state, so that means OFF if you came from OFF -- nice! No click&hold.
After I smashed one of my Basens flat top down from over tightening the cap, trying to get it to turn on and seeing how I have a bunch of new, used and mismatched 26500’s left over from different mods, I decided the BTU PK26 would serve me better using this format, so I converted back to a spring/ spring set-up. I’m liking this little devil now, it almost met it’s fate by Blow Torch! :rage:
Just for grins, I put a closely shaved E4 1D emitter in it, how about a smooth reflector now! :+1:
Nice idea! Can you still use 26350s with the short tube or is that option bye bye?
Hi LightRider
Nice try… We are modifying the stock PK26 with Springs too.
Ric
I'll keep on say'n it, but the LK 26650 is "the" cell for this light, besides being the best 26650 cell on the planet (low resistance and high capacity), and RIC sells them under a no-name (http://www.cnqualitygoods.com/goods.php?id=2250 ), but available at GearBest as well.
Now that is FUNNY! 
Don’t know, can the driver take 6volts? Or do you have a plan? :+1:
Short tube is for one 26350. It works, for a while, not very well though, or not very long after a full charge, as I reported in the review OP: https://budgetlightforum.com/t/-/41027.
Sorry Tom, I don’t follow this thread that much, must of missed it. But it’s the shortest 26650 I had, they still work in series and it gave me the idea to use the other wise abundant surplus I have on hand!
No prob, a good improvised solution. But for the general user, just want to make them aware the LK 26650 is available off the shelf and fits about perfect and performs great in this light.
Oh must of missed this too…. a short tube 26350? I noticed last night playing with it, that at 4.08volts the light jumps out of Turbo and only lets you use 4 levels, which is fine by me? Tried 3 different batteries and all failed holding Turbo at this voltage? Any ideas why?
In turbo mode, the battery current is very large (7-9A)
Ohh! Even on a 26650 at 4.08V or below? Yikes! Might not have tested that. Oh boy... I noticed it in the 26350 because it drains so fast. Should have done a full discharge test 
. I'm pretty sure the amps draw increases as the cell drains, to get more power - regulation kicking in. I guess there's some sort of limit on that draw though.
I was hoping RIC would come out with an improved driver that I could swap in. If not, I'd probably end up doing my own mod with a normal FET+1, or triple, and go with a dedomed XPL - it still throws decently for an OP reflector light in a small package. I invested in full trits on this one because I really like the host, so I'll make it work well regardless.
If he's adding springs to the PK26, then the changes are potentially more major, and a future driver update might not be backwards compatible (size, mount, etc.).
If RIC could chime in on this -- any idea whether an improved driver will be available?
You can roughly estimate the value of the current (1*li-ion)
1.5A*13V=19.5W (24W eff 75%)
19.5W/4.08V=4.78A (6.4A eff75%)
19.5W/3.7V=5.3A (7.02A eff 75%)
19.5/3.3=5.9 (7.87A eff 75%)
in reality my multimeter showed 7,8A and flashlight turning off turbo
all thats being said and done doesn’t make me feel good about my purchase 
Same here.
Did I buy an R&D work-in-progress?
it’s a nice light. I liked the form factor, that is why I purchased it. But with all this, springs, driver, etc and the possible switch going bad issue, it is the ONLY light I ever regretted purchasing. (some regret buying the Cometa CPF Italia, I absolutely love the light!)
Wouldn’t the 26350 just have more voltage sag than the bigger 26650? The little 26350 batteries at 3.8 volts are probably dipping down below 3 volts with an 8 amp load causing the low voltage protection to kick in.
The 26650 are bigger and probably doesn’t let thd voltage sag down as low under the same loads.
It seems the 26650 are what you want to run in the light normally The 26350 are just to wow your friends at how bright a tiny light is. Not very practical.