21700 Question

[AtomicMike421]

Hello everyone, I am relatively new to mech's, but not vaping (switched from cigs like 5-6 years ago) I finally decided to try a mech so after days of research about battery/mech saftey, I ordered one (THC tauren max). First of all, I'm like sad I didn't do this sooner, the vape I get off it is so insanely good! But theres one thing I cant seem to figure out... Using an 18650 is flawless, no problems at all. But if I wanna use a 21700, I've noticed that I often need to take much shorter hits, only because if I try to do a full breath inhale like I do with the 18650's, I can start to taste a dry hit towards the end. I always see others taking looooooong full breath inhales with their 21700 mechs, but I cant seem to do it with mine... The coils I use are various builds from coilclout/twizted timmys/rebels coils/MTN coils/etc.. Is it my wicking that could be causing this? I've tried loose and tight wicks but it feels like no matter what I do, it always seems to want to go dry before the end of my hit when using 21700's.... BTW the batteries I have are Molicel P28A 18650's and Molicel P42A 21700's. Any insight/tips would be greatly appreciated!

 

[ShowMeTwice]

Okay... so you have this mech???

What RBA are you using???

Dual or single coil???

Coil ohms???

A photo, or two, of your build would be very helpful.

 

[AtomicMike421]

Yes that's the one!
Dual 6-core aliens @ .12
On Twisted Messes TM24

 

[AtomicMike421]

Before the aliens I was running 5-core SFC's
They were .13 if I remember correcctly

 

[ShowMeTwice]

Yes that's the one!
Dual 6-core aliens @ .12
On Twisted Messes TM24

At 0.12Ω you are pushing the Molicel P42A 21700 beyond what Mooch (the battery expert) recommends.

Mooch rates the P42A at 30 amps.

On a full charge (4.2V) and 0.12Ω your P42A is drawing 35A and delivering 147W.

Here is Mooch's recommendation: The P42A is my choice for best all-around performing cell of any size and best choice for a regulated mod for use from about 40W-90W each (80W-180W in a two-battery mod). Below that there are ultra-high capacity cells like the Samsung 50E2 that are a better choice. At above 90W each or so the Samsung 30T could be the better choice. Try the P42A and 30T and see which performs better for the way you vape.

Bench Retest Results: Molicel P42A 4000mAh 21700...beats 40T, one of the best batteries available

These tests below only note the ESTIMATED ratings for these batteries at the time I tested them. Any battery that is not a genuine Samsung, Sony, Murata, LG, Panasonic, Molicel, or Sanyo can change at any time! This is one of the hazards of using...

www.e-cigarette-forum.com

Mooch does not recommend using the Molicel P28A over 25A. I would not even attempt trying a 0.12Ω build with that battery.

Bench Test Results: Molicel P28A (2021-dated) - 35A 2800mAh 18650

These tests below only note my personal ESTIMATED ratings for the batteries I tested at the time I tested them. Any battery that is not a genuine Samsung, Sony, Murata, LG, Panasonic, Molicel, or Sanyo can change at any time! This is one of the...

www.e-cigarette-forum.com

In your initial post you said "I am relatively new to mech's". With that in mind I would not be building so low. Build higher.

Don't take this the wrong way... being new to mech mods and trying to run a dual coil setup at 0.12Ω is just asking for trouble.

I use several different mech's daily and have never found the need, or a reason, to build any lower than 0.3Ω.

Good luck!!!

 

[AtomicMike421]

I understand what you're saying. I didn't start with a .12 build, My first build when I first got the mod was .25, second was .2, and third was .18. Those all vaped amazingly well too, but as soon as I tried that 5-core SFC at .12, that literally made me realize no WONDER there are still diehard mech fans. It really was kinda a "mind blown" moment LOL. But I don't believe it's "asking for trouble" like you say... I spent hours and hours reading up on this suff (and watching mooch) Browsing around, you'll find that the vast majority of premade coils SPECIFICALLY made for mechs tend to be around the .09-.2 area. I've seen a premade coil set for sale rated at .06, another at .08... using THOSE for me would feel like "asking for trouble"... So I've decided to keep it at .12 and up, which seems pretty common to be honest. I understand the risks involved, I don't even leave the house with my mech, its my "desk mod" lol. But I also know what to be careful of, what to watch out for, I never "chainvape" on the mech, it never gets hot. I do have some 30T's as well and some 25A's, which I'm definitely going to try, but still doesn't explain why basically everyone else is able to take long drags on 21700's with similar builds...

I actually do have a Valhalla mini 30mm that looks silly as hell on my mech (its for a timesvape Keen thats on the way) but that thing has friggen 3.5mm 9-core Aliens that seem to handle long 21700 drags a lot better than the other coils have... I'm pretty convinced that it has to be my wicking but who knows... I actually switched from COTN Lace to KGB cotton and that helped a lot surprisingly, seems much more heat-resistant.

 

[Hightech Redneck]

High wattage will go thru juice quickly.
Does sound like a potential wicking issue to me also.
Make sure the cotton is very snug in the coils. Also dont stuff cotton into the well, if its packed in it can choke and not keep the coil wet. In conjunction with that make sure there is enough juice in the well to keep the coil fed.

To me your over all description sounds like the wicking is not keeping up with your longer hits.
Try thinning the wick tails a bit and have them just long enough to reach the bottom of the well.

Every rda can require slightly different wicking to keep up.

Good luck!