Resistance Questions

[EmeraldKiwi]

So here is a setup I'm thinking about getting:
1x Uwell Crown Sub-Ohm Tank
1x Sigelei 150w TC mod
4x Samsung 25r 18650 batteries
1x XTAR VC4 charger

And I've got a couple of questions. As far as I know, the mod is run in series, which doubles my voltage to 8.4 theoretically at nominal battery capacity. So, does that double voltage affect how low I can fire my coils?

List of questions:

1. How low can I build with this mod and the batteries above?

2. The Crown tank comes with a .15 Ohm nickel coil head, so will I be able to use it on this mod and with these batteries?

3. If I can't fire the included TC coil, is there a different coil I can purchase to use the temperature control function?

Man, all of this is so confusing because the 25rs have a 20 amp continuous rating, so I don't know if they will handle .15 ohms. The confusing part is that the mod runs not one, but TWO 18650 batteries. I really need a good explanation of how the batteries work here, and if they will work. Thanks guys! I made an account literally to ask questions. XD

 

[EmeraldKiwi]

Alright, so I just found these specs from Sigelei's website:

TECHNICAL PARAMETERS:

Variable Wattage Range: 10.0W - 150W

Joule Range: 10J - 100J

Output Voltage Range: 1.0V - 7.5V

Input Voltage Range: 6.4V - 8.4V

Temperature Adjustment Range: 100-300°C / 212-572°F

Atomizer Ohm Range: 0.1 ohm – 3.0 ohm

Battery: 2* 18650 High-Drain Batteries

Max Current: 35A

Dimensions: 103 x 57 x 25mm ;

product Weight:210g

Total weight：340gg


So I guess if .1 ohms is safe with high-drain batteries, (according to the specs listed) my only question is how is that possible?

Since you said the lower resistance limit is unchanged regardless of whether the device runs in parallel or series, how can a 20 amp battery fire down to .1 ohms?

According to an ohms calculator, if I were to fire this little coil at the full 150 watts, I would be pulling 38.73 amps at .1 ohms. That's way higher than 20 amps. I guess now that I think about it though, that's why you don't fire these coils in wattage mode...
But even in TC mode... I'm unsure how the batteries can fire that low...

 

[Neunerball]

If you want to make use of the 150W, you would need something like the Sony VCT4. The rest is done by the mod.

 

[EmeraldKiwi]

If you want to make use of the 150W, you would need something like the Sony VCT4. The rest is done by the mod.

Do you think I will need all 150w of power for regular power mode with normal coils?

Would it benefit me at all to have the full potential available for temperature mode?

If I wanted to buy vtc4 batteries, where can I even buy genuine versions?

 

[Neunerball]

Most of the time, I'm utilizing tanks, and vape those between 29-37.5W. Only with a RDA, I'm going above 50W. The highest I vaped so far was 70W. That's why I'm fine with the Sony VCT5 (they also last a bit longer than VCT4).

 

[Slurp812]

Alright, so I just found these specs from Sigelei's website:

TECHNICAL PARAMETERS:

Variable Wattage Range: 10.0W - 150W

Joule Range: 10J - 100J

Output Voltage Range: 1.0V - 7.5V

Input Voltage Range: 6.4V - 8.4V

Temperature Adjustment Range: 100-300°C / 212-572°F

Atomizer Ohm Range: 0.1 ohm – 3.0 ohm

Battery: 2* 18650 High-Drain Batteries

Max Current: 35A

Dimensions: 103 x 57 x 25mm ;

product Weight:210g

Total weight：340gg


So I guess if .1 ohms is safe with high-drain batteries, (according to the specs listed) my only question is how is that possible?

Since you said the lower resistance limit is unchanged regardless of whether the device runs in parallel or series, how can a 20 amp battery fire down to .1 ohms?

According to an ohms calculator, if I were to fire this little coil at the full 150 watts, I would be pulling 38.73 amps at .1 ohms. That's way higher than 20 amps. I guess now that I think about it though, that's why you don't fire these coils in wattage mode...
But even in TC mode... I'm unsure how the batteries can fire that low...

Its regulated. So 38 amps, at the atty is not the same as battery current. 150 watts is probably close to 25 amps from the batteries tho. The build doesn't matter much on a regulated mod. Exactly how much involves very complicated formulas.

 

[robot zombie]

First thing's first. Temperature control resistances are a different animal. The coil only stays at an unsafe resistance for the amount of time it takes to heat-up, as nickel's resistance rises substantially when run at vaping temperatures. A .1 nickel coil at room temp will be at least double that at the minimum of 212F.

Do you think I will need all 150w of power for regular power mode with normal coils?

Absolutely not. I'd wager to say that most people don't even run above 100w.

Under 100w, you can build a .2 at the lowest and still be under-spec. This is more than enough with a regulated device. Hell, you can do some serious vaping at 50w. Higher resistance coils can perform very well at high OR low wattages, depending on the surface area. You can get clouds and/or flavor from something much higher than a .2... ...and you can run it below 100w.

Its worth mentioning that you can run a .32 at the full 150w and pull 21a. You can also undervolt coils below .2 to bring the amp drain under 20. If you wanted to, you could run a .15 at 60w and only pull 20a. A more realistic one would be a .18 at 70w.

.1 is really low. Some people are willing to go that low and run their batteries over-spec. With the right batteries, this is doable without going too far over-spec. The LG HB6 is a 30a cell, but it handles high-drain very well, and has been shown to be capable of handling 40a without overheating.

This implies some degree of risk, mostly for added wear. Most high-drain batteries can be run slightly over-spec with no trouble. It's not recommended because the safety margin is lower and it strains the batteries that much more. But that is to say that assuming your device doesn't misfire, then pulling say, 25a from a healthy 20a battery won't even come close to making it vent. Voltage will sag and the number of charge cycles will drop faster, but you haven't made a bomb.

Heat is the sign that you're pushing your batteries too hard. They can get quite warm with extended use and be fine, but when they're getting so hot that they're uncomfortable to hold, you're taking it too far. The cutoff point where batteries tend to fail is close to the boiling point of water.

If you ever want to stay completely cool and in the clear at over 20a, you're going to want VTC3's or preferably LG HB6's. You will lose capacity, but those batteries actually last longer at 30a than 20a batteries do at 30a and run cooler. You get better performance and a safer vape.

You can use http://www.steam-engine.org/batt.asp to calculate your amp load. Switch the device type over to "regulated." Switch it over to power regulation mode. All you have to do is find your device in the drop-down list, plug in the resistance of your build, and enter in the wattage.

This chart might help you pick batteries and give you some insight into where the realistic limits are. It shows where specific batteries start getting hot enough to fail as well as where they simply get hot enough to wear down faster.

If I wanted to buy vtc4 batteries, where can I even buy genuine versions?

http://www.illumn.com/ has them and many other great batteries at probably the best prices anywhere.They are one of the largest sellers of genuine batteries. You may want to look at what LG has to offer before going with the VTC's. VTC's are not true 30a batteries. They can handle 30a, but the temperatures they reach and the performance is not that of a real 30a battery. Honestly, I think the Samsung 25r is about as good for your money. VTC4's do not perform drastically better than it at over 20a.

 

[Neunerball]

Another good battery vendor is http://liionwholesale.com

 

[BoomStick]

First thing's first. Temperature control resistances are a different animal. The coil only stays at an unsafe resistance for the amount of time it takes to heat-up, as nickel's resistance rises substantially when run at vaping temperatures. A .1 nickel coil at room temp will be at least double that at the minimum of 212F.


Absolutely not. I'd wager to say that most people don't even run above 100w.

Under 100w, you can build a .2 at the lowest and still be under-spec. This is more than enough with a regulated device. Hell, you can do some serious vaping at 50w. Higher resistance coils can perform very well at high OR low wattages, depending on the surface area. You can get clouds and/or flavor from something much higher than a .2... ...and you can run it below 100w.

Its worth mentioning that you can run a .32 at the full 150w and pull 21a. You can also undervolt coils below .2 to bring the amp drain under 20. If you wanted to, you could run a .15 at 60w and only pull 20a. A more realistic one would be a .18 at 70w.

.1 is really low. Some people are willing to go that low and run their batteries over-spec. With the right batteries, this is doable without going too far over-spec. The LG HB6 is a 30a cell, but it handles high-drain very well, and has been shown to be capable of handling 40a without overheating.

This implies some degree of risk, mostly for added wear. Most high-drain batteries can be run slightly over-spec with no trouble. It's not recommended because the safety margin is lower and it strains the batteries that much more. But that is to say that assuming your device doesn't misfire, then pulling say, 25a from a healthy 20a battery won't even come close to making it vent. Voltage will sag and the number of charge cycles will drop faster, but you haven't made a bomb.

Heat is the sign that you're pushing your batteries too hard. They can get quite warm with extended use and be fine, but when they're getting so hot that they're uncomfortable to hold, you're taking it too far. The cutoff point where batteries tend to fail is close to the boiling point of water.

If you ever want to stay completely cool and in the clear at over 20a, you're going to want VTC3's or preferably LG HB6's. You will lose capacity, but those batteries actually last longer at 30a than 20a batteries do at 30a and run cooler. You get better performance and a safer vape.

You can use http://www.steam-engine.org/batt.asp to calculate your amp load. Switch the device type over to "regulated." Switch it over to power regulation mode. All you have to do is find your device in the drop-down list, plug in the resistance of your build, and enter in the wattage.

This chart might help you pick batteries and give you some insight into where the realistic limits are. It shows where specific batteries start getting hot enough to fail as well as where they simply get hot enough to wear down faster.


http://www.illumn.com/ has them and many other great batteries at probably the best prices anywhere.They are one of the largest sellers of genuine batteries. You may want to look at what LG has to offer before going with the VTC's. VTC's are not true 30a batteries. They can handle 30a, but the temperatures they reach and the performance is not that of a real 30a battery. Honestly, I think the Samsung 25r is about as good for your money. VTC4's do not perform drastically better than it at over 20a.

No, not really. Build resistance has nothing to do with battery current with vw mods. Go back to steam engine. Put multiple resistances into the battery drain section. You'll see that if the watt setting stays the same, so does runtime regardless of what build resistance you enter. Only adjusting the wattage will affect runtime. Watt setting divided by battery voltage gets you the approximate battery current. Build resistance is irrelevant.

 

[robot zombie]

No, not really. Build resistance has nothing to do with battery current with vw mods. Go back to steam engine. Put multiple resistances into the battery drain section. You'll see that if the watt setting stays the same, so does runtime regardless of what build resistance you enter. Only adjusting the wattage will affect runtime. Watt setting divided by battery voltage gets you the approximate battery current. Build resistance is irrelevant.

Ahh, hadn't considered that. Whoops! So basically what this means is that fresh batteries pushing 8.4v will only give ~20 amps to hit 150w, and the overall current drain will go up as battery voltage drops because the device will pull what it needs to hit that wattage. Makes sense.

Dunno how I neglected to consider something so simple. Shoulda really played around with that battery voltage bar a little more...

 

[Slurp812]

Ahh, hadn't considered that. Whoops! So basically what this means is that fresh batteries pushing 8.4v will only give ~20 amps to hit 150w, and the overall current drain will go up as battery voltage drops because the device will pull what it needs to hit that wattage. Makes sense.

Dunno how I neglected to consider something so simple. Shoulda really played around with that battery voltage bar a little more...

Realistically you'll never have 8.4 under load, but yes the concept is there! 150 is a bit much for 20 amp batteries. But only if you actually use it at 150. Im running my ipv4s (25rx2) at ~30 watts, so they don't even get warm chain vaping.

 

[ej1024]

Since ur gonna be using a regulated mod, the mod will do all the calculations, the mod will not fire if ur batteries are not able to supply voltage/amp required by ur desired wattage/ohms..
I'm vaping .15ohm on my sig150 not tc, at 70 watts with 77% battery life it's giving me 2.8 volts.

Unless you start vaping UNREGULATED then that's when you want to know ur batteries really well..
Yes in series u get 8.4 volts, but u don't really wanna VAPE 8.4 volts dude u will burn ur coil/cotton/mouth.

Remember those guys STACKING BATTERIES TO DOUBLE THE VOLTAGE??
Which wasn't really safe and stupid!!
VAPE ON


VAPE ON

 

[Slurp812]

Lets say you have a 20 amp battery in a regulated. Assuming the regulation works very well, and will pump out as much as it can get till it hits the low volt limit. So at ~ 3.0 volts and 20 amps, you only have 60 watts. If the mod is a 75 watt per cell deal, this will be ~25 amps. So realistically you can do ~72 watts with a fresh battery, and ~ 60 when its about dead.