How safe do you consider temp control?

[Matty316]

With ni200 coild being such low resistance say .15ohm and most high drain batteries having a max constant discharge of 20amps.
If for any reason your mod failed to regulate the power going to the coil a battery giving 4.2v at .15ohm would exceed that 20amp rating and could result in battery venting i'm guessing. Just wondering if anyone has heard of this happening or something similar happening?

I only ask this because i have just ordered my first temp control mod and this is one of the things that concerns me. I've been sub ohm vaping for a while now but not below .4ohm as i always like to err on the side of caution and like to be safe.

 

[degady64]

I consider tgat temp control is a step in front on the safe vape way. But it is at the begining.

 

[Margate69]

.15 ohm out of a max continuous discharge 20A battery is not a thing to play with. Even at 35A pulse draw, you are RIGHT AT the limit of the battery at 4.2v. Running coils like that is for experts only, and is NOT recommended for anyone. Know the risks.

 

[Matty316]

.15 ohm out of a max continuous discharge 20A battery is not a thing to play with. Even at 35A pulse draw, you are RIGHT AT the limit of the battery at 4.2v. Running coils like that is for experts only, and is NOT recommended for anyone. Know the risks.

I'm fully aware of the dangers this is why i have concerns about temp control. ni200 coils that are needed for temp control are genrally around .15/.16ohm because of it having such low resistance it would need a huge coil to get to anything like .4ohm.

 

[Margate69]

Even with temp control, I don't see this as "safe" at all. .15 ohm is past the safe area of any 18650 battery, no matter the manufacturer. Going .15 requires a 26650 battery, under that requires a parallel 26650 mod with 2 batteries.

 

[CloudyWithChanceOfVape]

At .15, a regulated box like a Sig150w with two 20a batteries can withstand this. (It would be 40a with both batteries operating.)

Also an Unregulated box with two 18650's with 20a ontinuous combined, (40a combination) could handle a .15 easily.

A .12 ohm is 35amps, so the 35 is getting CLOSE (waaay to close for me for comfort) on 40a continuous combo of batteries.

AND a .11 ohm coil is 38 amps.

This is all subjective and totally my own findings, and all based on a fresh 4.2v charged battery.

 

[Matty316]

I have to agree with you it seems dangerous to me which makes me wonder why these single 18650 temp control mods are sold. If for any reason that mod fails to regulate the current going to a coil that low resistance it would end in disaster.

 

[CloudyWithChanceOfVape]

Yeah I NEVER push my single 18650 mech mod below .3, and I have a vtc4 in it. I just don't trust that. lol.

 

[Matty316]

The temp control mod i ordered runs dual parallel 18650's but i still have concerns about using it.

 

[d4gger]

You're talking about the regulation circuitry somehow shorting? I'd be more worried about a positive battery terminal coming loose, contacting case, and dropping .01 ohm to the battery..

As far as ".15 ohms is inherently unsafe.." coil load is irrelevant in regulated output.. a 40W mod will pull, at most, about 16 Amps before cutting off on low battery voltage.

 

[AspireKaren]

Even with temp control, I don't see this as "safe" at all. .15 ohm is past the safe area of any 18650 battery, no matter the manufacturer. Going .15 requires a 26650 battery, under that requires a parallel 26650 mod with 2 batteries.

Hi there, you seems so professional ,can you tell me why this battery named 18650? I have no idea about it.

 

[Izan]

You're talking about the regulation circuitry somehow shorting? I'd be more worried about a positive battery terminal coming loose, contacting case, and dropping .01 ohm to the battery..

As far as ".15 ohms is inherently unsafe.." coil load is irrelevant in regulated output.. a 40W mod will pull, at most, about 16 Amps before cutting off on low battery voltage.

Please only contribute FEAR, Uncertainty and Doubt...

Remember: WHAT IF! Possibility = Probability

Carry on
I

 

[Margate69]

18650 battery = a size of battery. 26650 is a larger battery, capable of higher amp draws. LG, panasonic, and best of all sony make 18650 and 26650 batteries. But there is a LOT of fake brand name batteries out there.

To the other comments: I understand that a dual 18650 is an option to go down to lower ohms, I still have trouble with it, because running a low charge at 3.7 v is still unsafe territory, and most people don't keep a battery charger in their briefcase. That's all I'm saying on that matter.

 

[Matty316]

Don't get me wrong I'm not saying it is inherently unsafe, I'm just voicing my concerns and just looking for reassurance really that the mod I have ordered will be safe to use.

I've never used temp control before so it's a new concept to me.

 

[d4gger]

18650 battery = a size of battery. 26650 is a larger battery, capable of higher amp draws. LG, panasonic, and best of all sony make 18650 and 26650 batteries. But there is a LOT of fake brand name batteries out there.

To the other comments: I understand that a dual 18650 is an option to go down to lower ohms, I still have trouble with it, because running a low charge at 3.7 v is still unsafe territory, and most people don't keep a battery charger in their briefcase. That's all I'm saying on that matter.

I don't think dueling batteries is a great idea for lower ohms, especially not in a mech.. Throw dual mosfets on each battery before bridging them, and it's prolly become safer than running just one battery.

As far as the notion that a regulation device is suddenly going to fry closed (short) and dump battery to the coil, it is high unlikely. When circuits fry, they almost always fry open, and any reputable device manufacturer uses amperage-limiting circuits designed to stop boards from going dangerously wonky.

To address the general concern of driving a .low ohm coil with a regulated mod, we're going to do some quick napkin math.

Your .low ohm coil is going to be hit with, at most, p watts, where p is the maximum output power of your device. If we were using a mech, we'd care what .low is, but we're on a regulated mod, so if the mod will fire it, it shouldn't matter.

We'll use the formula P = V*I to find the maximum current we're ever going to pull. Since we want to solve for current, we'll rearrange to I = P/V. The mod should cutout for low battery voltage at about 3.2 volts, but we'll also do 2.8 volts just in case. So assuming you've got a 40 watt mod, we should be looking at: 9.5A at full 4.2 volt battery, 12.5A at 3.2 volt battery, and 14.3A at 2.8 volts. All well within 20A. I did not include your mod's overhead, but we're generally looking at 10-20% efficiency loss. This basically means add 10-20% to current draw. So at 2.8 volts battery charge, pushing 40W to the topper, you might be looking at 17A draw on the battery. That's pretty close to 20A, and I generally don't run my Samsung 25Rs (20A cdr) that close. However, that's a double-worst-case, and I doubt you'll get over 14A draw from the batteries if you've got a 40W single 18650 mod.

Now to what everyone else seems to be concerned with.. would I ever mech .15 ohms? No, no, no.. Anything below .19 ohms causes my VTC4s to get warm within moments, and I don't like when my batteries turn to heating elements. And I don't enjoy really enjoy anything over 50 Watts anyway, so I like my .4ish ohm coils just fine

And finally, as to your mod being safe to use, that'll depend on who made it, but I expect it will be a biscuit 'n gravy train. Happy choo choos

 

[Matty316]

I don't think dueling batteries is a great idea for lower ohms, especially not in a mech.. Throw dual mosfets on each battery before bridging them, and it's prolly become safer than running just one battery.

As far as the notion that a regulation device is suddenly going to fry closed (short) and dump battery to the coil, it is high unlikely. When circuits fry, they almost always fry open, and any reputable device manufacturer uses amperage-limiting circuits designed to stop boards from going dangerously wonky.

To address the general concern of driving a .low ohm coil with a regulated mod, we're going to do some quick napkin math.

Your .low ohm coil is going to be hit with, at most, p watts, where p is the maximum output power of your device. If we were using a mech, we'd care what .low is, but we're on a regulated mod, so if the mod will fire it, it shouldn't matter.

We'll use the formula P = V*I to find the maximum current we're ever going to pull. Since we want to solve for current, we'll rearrange to I = P/V. The mod should cutout for low battery voltage at about 3.2 volts, but we'll also do 2.8 volts just in case. So assuming you've got a 40 watt mod, we should be looking at: 9.5A at full 4.2 volt battery, 12.5A at 3.2 volt battery, and 14.3A at 2.8 volts. All well within 20A. I did not include your mod's overhead, but we're generally looking at 10-20% efficiency loss. This basically means add 10-20% to current draw. So at 2.8 volts battery charge, pushing 40W to the topper, you might be looking at 17A draw on the battery. That's pretty close to 20A, and I generally don't run my Samsung 25Rs (20A cdr) that close. However, that's a double-worst-case, and I doubt you'll get over 14A draw from the batteries if you've got a 40W single 18650 mod.

Now to what everyone else seems to be concerned with.. would I ever mech .15 ohms? No, no, no.. Anything below .19 ohms causes my VTC4s to get warm within moments, and I don't like when my batteries turn to heating elements. And I don't enjoy really enjoy anything over 50 Watts anyway, so I like my .4ish ohm coils just fine

And finally, as to your mod being safe to use, that'll depend on who made it, but I expect it will be a biscuit 'n gravy train. Happy choo choos

Thanks this makes me feel more confident but it still scares the heck out of me. I'm sure i'll try it at some point but for now i think i'll keep it in wattage mode and stick with my .4 kanthal build untill i feel a little more brave lol.

 

[holyseano]

In my experience temperature control is a bit janky sometimes but once you find the right RDA and the right build for you its more than amazing. If I had the choice i wouldnt go back

 

[K_Tech]

"Safe" is in the hands of the QC department.

Certainly, throwing a 0.15 ohm build on an unregulated 18650 mod is a questionable practice, but on a properly designed regulated mod, you're never going to pull more current than the current limit of the device.

Similarly, a lot of these 70-100-150 watt mods provide their rated power inside an operating envelope, restricted by their power, current, and voltage limits.

Unless something fails on the chip which would allow battery voltage to be dumped straight to the coil, you're safe.

 

[bsidb]

wouldnt the coil just burn up before any battery damage?

 

[jseah]

You're not using temp control on a mech mod, so you are never going to dump a battery's full power into a nickel coil. At 4.2 volts with a 0.1 ohm nickel coil, Ohm's law calls for 176.4 watts. The DNA40 temp control chip limits your output to 40 watts. So with a 0.1 ohm coil, that 40 watt limit means you are only putting out 2 volts, or 20 amps. And with the DNA40 chip, you can't fire a nickel coil below 0.1 ohm.

Is it possible for the chip to have a complete failure and stop regulating the power, so it does allow a full 4.2 volts to be passed? I'm not an electrical engineer with knowledge in circuit board design, so I don't know. My guess is if the chip had a complete failure, rather than allowing the power to be passed directly from the battery to the coil, it just wouldn't fire period.