Become a Patron!

Building for a 21700 mech stack

daisy cutter

Member For 1 Year
I picked up a Purge Stack Piece yesterday along with an Armageddon Redemption RDA with silver deck and Ti cap. I’ve been running a 20700 Purge stacked Basic with a Carnage rda. The build I have in the Carnage is an 8 rap fused Clapton. 26ga Ni80 cores and 32ga Ni80 wrap. Ohms out at .25 and fits perfect in the Carnage deck. The same build in the redemption deck is a little too close to the walls of the cap for my comfort. I’m considering a 28core 38wrap with 5 wraps which should ohm out at the same .25. My question is, is going with thinner wire a bad idea on a 21700 stack? Any other build suggestions are welcome, .25ohm range with Ni80 wire.
 

Carambrda

Platinum Contributor
ECF Refugee
Member For 5 Years
The problem is with thinner core wires and reduced number of wraps, the total surface area of the coil will be smaller. Having not enough contact area between the coil and juice, while at the same time also throwing such high power (watts) at it, tends to be a recipe for getting a burnt-like undertaste if the pull duration isn't kept really short (and despite doing really hard pulls, much to the point of almost sucking the juice right off of the build deck and into your mouth), especially IME if using fused claptons. Dual coil staggered fused claptons 28/36 Ni80 at 7 wraps, 3mm ID will work better IMO because the Samsung 30T battery is simply a much harder-hitting battery than all the rest. At only 2.5mm ID instead of at 3mm ID, here is what this same build looks like in my 24mm Mason V2 at .26 ohms (IMO just the perfect ohms number for this build on a stacked mech using two iJoy 5-legged 20700s).

sfc.jpg
 

Bigrick

Gold Contributor
Member For 4 Years
ECF Refugee
Maybe just my lack of experience with mechs but those are some pretty low ohms. I have not done the ohms calculating but dont you want to be around .4 ohms at 8.4 volts?
 

MrMeowgi

The Vapin' Drummer
VU Donator
Diamond Contributor
Member For 4 Years
Maybe just my lack of experience with mechs but those are some pretty low ohms. I have not done the ohms calculating but dont you want to be around .4 ohms at 8.4 volts?
Bigger dicks man. It's all about bigger dicks. And inhaling Satan's jizz. Lol .4 is as low as I go in series. Not really into 180+ watts

Sent from my LM-Q610(FGN) using Tapatalk
 

Bigrick

Gold Contributor
Member For 4 Years
ECF Refugee
If the 30t is a true 35a battery maybe. But they are talking like 34a @285 ish watts. Too close and hot for my likes.
 

zephyr

Dirty Pirate Meg
VU Donator
Gold Contributor
Member For 4 Years
Unlisted Vendor
Maybe just my lack of experience with mechs but those are some pretty low ohms. I have not done the ohms calculating but dont you want to be around .4 ohms at 8.4 volts?


Check out Mooch's charts for battery discharge and voltage drop, here it is for the Samsung 30T:

81883a53-47ff-4ba2-97f4-bfd63fabf3f5-jpeg.743063


Check the blue line for 30 amp discharge - at full 4.2 volt charge, under a 30 amp load this battery puts out about 3.8 volts, this is what you can use to calculate wattage with coils that draw 30 amps

Doubled for series, 7.6 volts

I dont like super low builds either, though
 

zephyr

Dirty Pirate Meg
VU Donator
Gold Contributor
Member For 4 Years
Unlisted Vendor
Then consider these are voltages under continuous discharge, and vaping involves pulling current and then allowing batteries to rest (unless you take a puff repeatedly, dont do that)

Some people build very low, going over a battery's continuous discharge rating (CDR) but allowing the battery to rest, and cool, between puffs. I don't, I like using two batteries in parallel :D to each his own as long as he's educated
 

daisy cutter

Member For 1 Year
The problem is with thinner core wires and reduced number of wraps, the total surface area of the coil will be smaller. Having not enough contact area between the coil and juice, while at the same time also throwing such high power (watts) at it, tends to be a recipe for getting a burnt-like undertaste if the pull duration isn't kept really short (and despite doing really hard pulls, much to the point of almost sucking the juice right off of the build deck and into your mouth), especially IME if using fused claptons. Dual coil staggered fused claptons 28/36 Ni80 at 7 wraps, 3mm ID will work better IMO because the Samsung 30T battery is simply a much harder-hitting battery than all the rest. At only 2.5mm ID instead of at 3mm ID, here is what this same build looks like in my 24mm Mason V2 at .26 ohms (IMO just the perfect ohms number for this build on a stacked mech using two iJoy 5-legged 20700s).

View attachment 121796
This is the conclusion I’ve come to as well after thinking about it more after my post. I’m thinking of trying a 4mm 7 wrap of 26/32 fused Clapton’s....if it will fit on the Redemptions build deck. It should ohm out at .25 and 33.6amps. Well within the “safe” operating cdr of the 30T
 

r055co

VU Donator
Platinum Contributor
Member For 4 Years
This is the conclusion I’ve come to as well after thinking about it more after my post. I’m thinking of trying a 4mm 7 wrap of 26/32 fused Clapton’s....if it will fit on the Redemptions build deck. It should ohm out at .25 and 33.6amps. Well within the “safe” operating cdr of the 30T
Fine with the 30T's, but around 270W that's way to fucking hot for my tastes
 

daisy cutter

Member For 1 Year
Fine with the 30T's, but around 270W that's way to fucking hot for my tastes
It’s what I’m pulling now with 8 wraps with a 3.5 id. I’m just looking for a little more room on the build deck. The 8 wraps is a little too close to the side walls for my comfort. Not touching but a little more clearance would be more comforting.
 

Carambrda

Platinum Contributor
ECF Refugee
Member For 5 Years
Bigger dicks man. It's all about bigger dicks. And inhaling Satan's jizz. Lol .4 is as low as I go in series. Not really into 180+ watts

Sent from my LM-Q610(FGN) using Tapatalk
Long soft draws lasting more than just a few seconds make me feel seasick.
 

Carambrda

Platinum Contributor
ECF Refugee
Member For 5 Years
Then consider these are voltages under continuous discharge, and vaping involves pulling current and then allowing batteries to rest (unless you take a puff repeatedly, dont do that)

Some people build very low, going over a battery's continuous discharge rating (CDR) but allowing the battery to rest, and cool, between puffs. I don't, I like using two batteries in parallel :D to each his own as long as he's educated
As long as you don't go too far above the CDR the battery doesn't heat up so fast that you can't chain vape it. But there's a difference between chain vaping it knowing when to stop and chain vaping it all the way until the battery reaches to insane high temperatures... I stop before the battery temp can get to 45°C because above that is where our typical round cells we use for vaping start aging faster than normal, and, I make perfectly sure it can NEVER get close to becoming seriously hot because I know how to prevent accidental long button presses and also I know how to immediately instantaneously stop my mechs from auto-firing, just like I know how to prevent my mechs from hard shorting the batteries... I mean, all this knowledge and discipline is part of the same mech philosophy about safety... By taking out the battery and feeling how warm it gets, you can familiarize yourself with the relationship between how you vape on a certain coil build and how fast a certain battery heats up inside your mech. If you wrap your fist around the battery and you can't hold it like that for 30 seconds because of how hot it is, then it is waa-aaaa-aaaaaaay too hot. Mine never get much warmer than the temperature of my own skin so that's how I know they're always below 45°C. The Sony VTC5A is rated by Sony to be discharged CONTINUOUSLY up to a maximum of 35 amps PROVIDED that the battery temperature is kept below 80 DEGREES Celsius. (Even, though it isn't without added risk, but then again, I don't discharge it continuously at 35 amps because, instead, I still let go of the button between puffs despite chain vaping it, and I don't let it go up to 80°C because like I said I only go up to 45°C... so there is still reasonable enough headroom for keeping it reasonably safe as long as you stay reasonable and you also fully understand and can accept both the added risk and the discipline part about the safety of course...) For me, personally, at .11 ohms on a mech with a single Sony VTC5A battery is safer than walking across the street, but that doesn't also mean I actually go as far as to recommend it to anyone. So whatever you do don't walk across the street, as you really do need to forever stay inside that padded room wearing that flannel suit stuffed with pillows or else I promise you you'll get hit by a bus, and you'll get hit by it before yesterday. :D
 

VU Sponsors

Top