How safe do you consider temp control?

[Troll from behind]

Well it's SAFER, than doing .15 with a mech.
Things can go wrong EVEN with the best of em, but knowing your batteries gets you far.



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[dhood]

Temp control is probably the next generation of safe vaping. However, it is still in its infancy. I see a lot of vendors rushing to the market with products to jump into the pool. Some are good, some... not so much. I've watched all of Busardo's videos on temp control mods and the one thing that is common is that they do temp control, in his words, "sort of".
The batteries themselves are not advancing at the same pace as vaping technology. I'm not sure any of the battery makers really have us in mind when they design these. So the responsibility for regulating that power flow safely falls on the chipsets of the mods. At builds down to .1, that is a razor's edge of safety.

 

[rurwin]

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

18 -- The diameter of the battery = 18mm
650 -- The length of the battery is 65.0mm

That last zero may be reserved for future use because so far as I know it is always zero, but I think it is supposed to be the tenths of millimetres. In practice the length differs by more than a millimentre if the battery has a nipple-top or if it has a protection circuit, but it's still called an 18650.

 

[AspireKaren]

18 -- The diameter of the battery = 18mm
650 -- The length of the battery is 65.0mm

That last zero may be reserved for future use because so far as I know it is always zero, but I think it is supposed to be the tenths of millimetres. In practice the length differs by more than a millimentre if the battery has a nipple-top or if it has a protection circuit, but it's still called an 18650.

wow ,thank you so much for you help. I think at least i got the basic knowledge of why it's called 18650. lol

 

[mesamay2003]

Well, the recommended range for TC on the new iPV4 is .05 to .1 ohms, so I assume there are some built in safety features using nickel wire built that low...

 

[jseah]

Well, the recommended range for TC on the new iPV4 is .05 to .1 ohms, so I assume there are some built in safety features using nickel wire built that low...

Sure there is. The IPV4 will not go above 100 watts.

 

[RandyF]

Safer than anything out there that isn't temp controlled, at least as it pertains to Evolv's chip. That said, I have 2 rDNA40's and I use both of them primarily with kanthal in STm's. I enjoy TC, but tend to only utilize it in RDA's.

I would say the chances of the chip failing to regulate the power in any situation would be very low to impossible. It would likely completely fail before a singular function like that would fail.

 

[Margate69]

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

Depends on series or parallel. If you have 2 batteries in a parallel circuit, you double your amp draw but maintain your voltage of a single battery. This makes it MUCH harder to overload your battery, and therefore much safer. Series 2 batteries is the opposite. Doubles your voltage, maintains your amp draw, not good for below .3 ohm.

 

[nyiddle]

I think a lot of people missed the plot here.

Try and do a nickel build above .3 ohms. Very hard, quite impractical.

If you're using a regulated (and you are, if it's TC) mod, you'll have no problems with a .1 ohm nickel build.

Obviously don't put the same build on an unregulated device.

 

[Alien Traveler]

sorry

 

[jaxgator]

And with the DNA40 chip, you can't fire a nickel coil below 0.1 ohm.

This is incorrect information. The DNA40 will, in fact, fire a coil lower than 0.1Ω. Granted, it won't push it at 40w but it will fire it. I have fired a 0.06Ω Ni200 coil with a DNA40. Buck/boost technology and all that. Of course, Evolv recommends a range of 0.1Ω to 1.0Ω for Ni200.

 

[edyle]

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.

If it's a 40 watt box, the electronics should only be able to output about 10 amps anyway.
The problem could only occur is the electronics was bypassed.

 

[hashtag]

If the circuit board or any components failed it just wouldn't fire. The electricity has to pass from the battery through the circuit. If the circuit fails no electricity makes it through.

 

[Mooch]

If the circuit board or any components failed it just wouldn't fire. The electricity has to pass from the battery through the circuit. If the circuit fails no electricity makes it through.

When some power components fail they can become very low resistance, essentially a short circuit for any current. If the main MOSFETs on a regulator board fail (due to overheating, voltage spikes, etc.) they can get stuck turned "on". The current could just flow right through the board without regulation depending on the design of the board.

If the current flow is high enough the MOSFETs literally melt their internal wiring and pop. This opens the circuit and stops the current flow. But if the current flow isn't high enough to open the MOSFETs then there could be trouble.. The current will flow unregulated into the coil. Not saying this is likely, quite the opposite. But I have seen some truly spectacular power supply failures when the MOSFETs were damaged and shorted out. Sounded like small caliber gunfire as the MOSFETs finally blew.