Thanks for the feedback. 
Currently there don’t seems to be many sellers who can ship batteries to my country now, while this Vapcell store seems to be able to ship. I may buy a pair of 2665 for my L7 too.
Can someone explain to me why you would want to run such a powerful light off two tiny batteries? Not to mention, the big head/ short tube will make it very unbalanced?
Zoulas, when putting a short 26650 tube on either the L7 or L6, you can carry it around much easier; it is just about the size of an Astrolux FT03.
I confess to having one serious weakness: I like to buy flashlights that come with an extra shorter tube. Such as : Astrolux FT03 Mini, Astrolux EA01, and Lumintop GT Mini Pro.
Feel less painful to pay for one, but getting two flashlights. 
Just ordered two pieces of 26650 Vapcell button top from Ali Express for use in my L7. I have mostly flat-top 26650 cells and they cannot make good contact to power up the L7 in a more stable manner.
Interested. Thank you.
Just because we can. It’s a little customization that gives our tools and toys a little more personality. A bit of my quest for 26800 mods or putting 18350 tubes on 18650 lights that I can. It’s that guy that pulls an extra 100 horse power out of his vehicle or paints it. Zoulas what do you love and take to the next step? Not every step is a step up. Some are one back or to the right/left just something that says this is mine.
For those that have already got an L7, I’m curious what 26650’s you’re using and how they’re working out for you.
I just paired a couple of these Keeppower 5200 mAh with my L7. While they make contact in series, the lack of a driver spring seems to make the L7 more sensitive to battery length. When I point the L7 up in the air, the batteries lose contact with the driver.
I had to use slightly longer cells. Factory INR26650-55A don’t work but do in the L6. The Keeppower raised top 5500mAh work in my L7 and their a fraction shorter 0.6mm. Flat tops probably aren’t getting enough pressure for good between cell connection. I’ll probable put longer heavier double springs in the tail cap.
I use Liitokala’s. I had to wait for a bit because they were too short (accidentally bought flat tops). Bought some rare earth magnets on BG and the fit is now perfect, only needed one magnet to make the fit.
Saw that Convoy had them as an option on their Aliexpress site, just didn’t notice they used button top.
I’m currently using Vapcell BT | Vapcell original 26650 battery 4200mAh - 4300mah 32A rechargeable li ion 3.7V batteries cell
I am using two Supfire button top 5200 mAh AB11 cells. They came with a Supfire flasghlight I had brought from Supfire on Lazada Singapore a few months ago.
I think L7 needs button top cells to work properly. I have ordered four button top Vapcell 26650 cells from Ali Express for use on both my L7 and L6 flashlights.
I’ve also observed that, depending on the 26650 battery used.
Most flat-top 26650 batteries, I measured to be just around 64.9 - 65.5mm length (Shockli/Vapcell 5500mAh 26650, Liitokala Lii-50A flat-top, iJoy 4200mAh 26650, HLY 5000mAh 26650, some Sofirn’s 5000mAh/5500mAh 26650).
(note that Sofirn’s 26650 batteries have a few different types, some are a bit longer and have a different top design - I’ve seen around 3-4 different top designs (flat-top) for Sofirn’s 26650 batteries).
When these are used on the Convoy L7, pointing the flashlight upwards may sometimes cause the light to disconnect power.
Some longer 26650 batteries I’ve tested work better:
Liitokala Lii-50A 26650 “raised-top” version, around 67.0mm
Vappower 5200mAh 26650, also around 67.0mm length
Sofirn/Wurkkos 5000/5500mAh 26650 (button-top), around 67.0mm length
These 2 longer batteries, won’t cause the light to turn off with the L7 pointing upwards, but vigorously shaking the flashlight may still cause power to disconnect.
even longer 26650 batteries would be protected ones.
Keeppower P2660C 6000mAh protected 26650, ~69.0mm length (note this battery is slightly thicker, similar to Vapcell/Shockli 5500mAh 26650)
Keeppower P2652C 5200mAh protected 26650, ~69.8mm length
with these longer protected 26650’s, the flashlight won’t turn off even when shaking the flashlight.
~
for the shorter flat-top 26650 batteries, I’ve tried using a 12mm x 3mm or 12mm x 4mm neodymium disc magnet to add more length, so that they fit better (won’t disconnect unless shaking vigorously) on the L7…
interested
I’m interested in L7.
Thanks D_T_A for sharing your information.
I have been trying different 26650 batteries in my L7 and L6. Indeed the flat-top ones don’t give stable connection.
You mentioned at the end about using some magnetic spacer on flat-top batteries. I have a question : Will the magnetic spacer create any unintended / adverse side-effects in the flashlight that we should watch out? Such as disrupting the UI? I hope not.
Adding a magnet spacer just basically extends the length so the batteries won’t disconnect from the flashlight, so there should not be any unintended effects.
It’s possible that the magnet may add a slight amount of resistance (meaning a very slight decrease in total power due to added resistance)… however it also has an added effect because the tailspring will compress better and should thus make better contact. (so I’m not sure if the end result is better or slightly worse in terms of current being given to the flashlight).
Possible unintended effect: if the magnet slides to somewhere else, then there’s always the risk to short-circuit something inside the tube… but I think as long as the battery are placed properly, and the magnet is strong enough to not slide out of position (the magnet should be long enough so the tailspring will compress well), there shouldn’t be a problem.
Thanks d_t_a for your kind response.
I have just ordered four pieces of magnet spacers on Shopee Singapore, each costing S$1.80, about US$ 1.30.
Will use them with my flat-top batteries in L7 and L6 flashlights soon.
Convoy carries this. https://www.aliexpress.com/item/1005003031942340.html?spm=a2g0o.store_pc_groupList.8148356.1.d704c2b52OLxVV This should take care of spacing issues with flat tops. He also indicated he would make them in 21mm and 18mm.
Interesting gizmo.
Is this because of gas prices?