BEHEMOTH : Kaly XL-R build on steroids

This is my first log thread, so bear with me.

Late last year I moved from Lithuania to Seattle for work. Due to battery shipping being a huge PITA I couldn’t bring my beloved flux across the pond and so it was a great excuse for a new build.

Previous board
  • Flux AT2
  • 12s10p BAK N21700CG
  • FlexiBMS
  • Finality AT 1:4 on fatboy 320 trucks
  • Bloody unity
  • Maytech 6396 140kv

Planned specs

  • Kaly XL-R deck and enclosure
  • 18s11p LG M50LT
  • Finality AT 1:5 103mm
  • SKP Dual esc
  • SKP 7490 135kv

Main goals

  • At least 100km of fun range
  • Enough power to haul my 100kg butt up Seattle hills


I started looking for a deck in December and came across a kaly xl-r combo deal that was too good to pass up. It bears resemblance to the flux which I enjoyed a lot and can fit a massive amount of cells.


Originally I planned to go the simple and clean route with the included PCB for a 20s8p configuration. However, at the time, my only options for an ESC were either the DV100 (out of stock) or the spintend :firecracker:

Luckily, @Skyart announced the SKP solo series, so 18s it is.



Since the decision to downgrade to 18s meant pcb would not work I had to find a way to fit more cells. Luckily there is just enough height inside the battery compartments to fit a staggered triple stack. An additional gasket will still be required because of the concave.

That meant a 18s11p config. Cell decision was entirely based on @Battery_Mooch test results Bench Test Results: LG M50LT - 14.4A 4932mAh 21700 | E-Cigarette Forum .

This cell outperforms both the Samsung 50S and BAK N21700CG-50 at 5A. At 10A the Samsung 50S beats this cell by a few percent but the M50LT still performs a touch better than N21700CG-50. This makes the LG M50LT one of the best performing 21700’s we can buy. I have not tested its cycle life yet though.

5A per cell at 18s11p is 3564W, this is more than enough for casual riding and I can pull up to 10692W :fire: at 15A/cell if needed and temps are good.

More will follow soon, all parts should be here by the end of the week.


Looking like one beast of a build, sounds like plenty of torque to tackle those hills.


We have a telegram group if you want to chat or post up rides. @Yeahthatperson leads a monthly ride in Redmond 2nd Thursday of every month.


Definitely, send me a link to the chat if you have one. Would be nice to meet some like minded lunatics. Hopefully, the snow melts before the next ride.


Wow this is a crazy spec build!


Goodies have arrived, it’s gonna be a fun evening putting on the fish paper rings.


Holy shit that’s a lot of cells, looking forward to how this build turns out. This thing is gonna be HEAVY. :fire:


So can you throw out a guess of what this monster is going to weigh.

I hope it brings you as much joy as the Flux!!!

2023 BOTY, calling it out now.


I’ll try to get you some numbers. It’s definitely going to be a beefy boy :sweat_smile:

Where r u located, definitely down to meet up if ur near Lynnwood.


Wow this one looks awesome. I am working on a similar build but planned to be 1214P of Samsung 50S, 4 x 7490 173 KV, quad SKP Solos and Finality AT 1:3. I definitely think these 5000 mAh cells are the way to go now especially for larger packs.


Depends on how many P groups you have. Larger P groups can definitely benefit more from high capacity cells. I have a 12s12p P42a, my discharge amps is way more than I’ll ever need for 2WD lol.




I have the same 12s12p setup, 55 lbs


What’s your source for the 50S’s? I found them but $$$

Yeah I know. I was very lucky to get them on Black Friday special from 18650batterystore. I think they were USD 5.99 at the time.


It was SUCH a good deal

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The build is moving forwards, albeit a bit slower than expected.

Got the nickel cut and welded on, still waiting on a few cells to arrive for the last group.

the stock wire grommets had to go, filled in the holes with the leftover carbon from the heatsink hole.

assembled the gear drive. Fun fact: the 1:5 ratio in 103mm body is only available for 8mm shafts, so the 7490’s had to be custom ordered from @Skyart

rolling chassis complete


Sadge….I have the big ones 127 and they only come in 10 I think haha reverse problems