Different Chipsets giving different resistances

[Rob Fisher]

With the coil testing I have been doing recently I have discovered that different chipsets and different mods all give slightly different resistances to the same coil in the same tank. The coils with stainless steel in them give way different readings but that is because SS's resistance changes depending on the temp of the wire.

But these tests are with our Ni80 Coils
DNA60 Stratum V7 - 0.46Ω
DNA60 IF Mods - 0.43Ω
DNA75C - 0.43Ω
YiYi 485J - 0.42
DNA100C - 0.43Ω

 

[Teunh]

Thats probably the difference in the internal resistance setting.

 

[Grand Guru]

I think at that resistance range, +/- 0.04 is acceptable. I'd be worried if the coil resistance less than 0.2 especially on a mech mod

 

[Puff the Magic Dragon]

The difference between 0.42 Ohms and 0.46 Ohms is tiny. The max difference is 0.04 Ohms. I know that I would not notice any influence on the vape experience. It would be more noticeable at lower resistances such as 0.15 Ohms and 0.19 Ohms.

The differences you are seeing are all on DNA mods which are known to be accurate. I suspect that you would see much greater differences on cheaper chipsets. I know that this would bother some vapers but I am not one of them. I like to alter my vape experience fairly often. I may alter the Watt setting by up to 20W on the same coil. I like cooler vapes and yet sometimes I like to spice things up by having a warmer vape when the mood takes me. It also alters the juice flavour.

I tend to vape according to the vape experience rather than the wattage setting. I only use the Ohms reading to make sure that I don't burn a coil or the cotton. I know that some vapers like to stick to a particular wattage setting for a particular resistance coil. If their mod reads resistance inaccurately this would bug them when changing mods. My only requirement would be that the inaccurate mod should always read the same coil consistently inaccurately.

 

[Timwis]

Actually for a DNA device the 0.46ohm reading seems a bit of an outlier but as @Puff the Magic Dragon is still a tiny difference in relation to resistances around 0.4ohm, it would bug me why a DNA device is showing this difference though! Apart from the DNA60 Stratum V7 though your list to me is the opposite to what your post seems to be implying and is actually an advert for the consistency across DNA chipsets and that the YiHi is as accurate. If you think about it 0.424 would show as 0.42 but 0.425 (i believe if not definitely 0.426) would show as 0.43, so many variants could contribute to that fraction difference!

 

[M.Adhir]

Ob the older B/W DNA chipset using SS coils or SS Hybrids, you should get ohm jumping as you press the fire button.
That's nothing to be alarmed about as long as the coils are balanced etc.
On the DNA-C you're likely to get the most stable reading of the lot (my findings so far, but the Yihi is pretty accurate as well within small margins).

Accuracy within those variances- can be anything from the length of the internal wiring between board and 510 or board and battery or the contact being made between the atty and the mod.

 

[DarthBranMuffin]

Also the matter of calibration comes at play here. The High End hand-made mods get calibrated for peak performance where your mainstream is more plug-and-play during manufacturing. @Mauritz55 can get more into detail here with the calibration aspect.

But minimal variances between mods should not take away anything on performance and power, unless the power output is also affected by the chips performance and setup.

 

[Mauritz55]

Not all chipsets gets calibrated by the mod makers!
Escribe has a function to see what your internal resistance is in regards to how it was made ie:wire gage and tipe of solder used and of course the battery tube contacts.
So plug your device in when Escribe is open then go to the page where you can see your mods internal resistance without a RDA/RTA connected,then short the 510 and you will get the internal resistance and save it!Remember to upload the settings on your mod and Boom your mod is calibrated and coil resistance would be accurate.
If someone needs help I can do a Remote Desktop and help with settings and calibration

 

[Viper_SA]

I've experienced the same thing to a much greater extent. I use White Collar mtl coils in all four of my Expromizer V4's. Advertised resistance is 0.75 ohm. On different mods the coils differ from 0.82 to 1.04 ohm. I just still hit them all at 20W and let them sort themselves out. But it does bug my OCD a bit.

 

[Timwis]

I've experienced the same thing to a much greater extent. I use White Collar mtl coils in all four of my Expromizer V4's. Advertised resistance is 0.75 ohm. On different mods the coils differ from 0.82 to 1.04 ohm. I just still hit them all at 20W and let them sort themselves out. But it does bug my OCD a bit.

Is that a difference coil to coil though or the same build showing difference resistances on different devices? If it's coil to coil then that allows for far more variants like how long the leads are left and even things like how tight the leads are secured!

 

[Viper_SA]

Is that a difference coil to coil though or the same build showing difference resistances on different devices? If it's coil to coil then that allows for far more variants like how long the leads are left and even things like how tight the leads are secured!

Same build on different mods. I just came to the conclusion that it's not the best coils, but I like them nonetheless. Doesn't really make a big difference in the vape at a constant wattage on all four RTA's though, so 20W it is, lol.

 

[Timwis]

Same build on different mods. I just came to the conclusion that it's not the best coils, but I like them nonetheless. Doesn't really make a big difference in the vape at a constant wattage on all four RTA's though, so 20W it is, lol.

Wow, that is some major differences with the same build device to device! Is it a one off coil or the same whenever you use those coils? If you were a newbie I would be suspecting at least one of your leads were not secured tight but it can't be that so absolutely no idea?

 

[Viper_SA]

I have changed coils once or twice with the same result. The one reading high stays high though, and the lower reading one stays low so at least it's consistent on the same mod all the time. Must also say they are older mods, so perhaps the "fancy" coils confuses them a bit.

 

[Timwis]

Doesn't really make a big difference in the vape at a constant wattage on all four RTA's though, so 20W it is, lol.

The advantage of setting by wattage if you set to 20w it will give 20w regardless and usually i would have the same attitude but even @Puff the Magic Dragon who also things like this doesn't bother him would think hey up, something is amiss here, 0.82 to 1.04ohm is a massive variant for a settled build to be reading device to device, it can't be the devices even the lower end chipsets are not that inaccurate!

 

[Timwis]

I have changed coils once or twice with the same result. The one reading high stays high though, and the lower reading one stays low so at least it's consistent on the same mod all the time. Must also say they are older mods, so perhaps the "fancy" coils confuses them a bit.

Maybe needs an expert @charln any idea?

 

[Timwis]

I have changed coils once or twice with the same result. The one reading high stays high though, and the lower reading one stays low so at least it's consistent on the same mod all the time. Must also say they are older mods, so perhaps the "fancy" coils confuses them a bit.

I mean as you know a build when bedding down can be all over the place until bedded in but to clarify you are saying this is with a bedded in build?

 

[Viper_SA]

I mean as you know a build when bedding down can be all over the place until bedded in but to clarify you are saying this is with a bedded in build?

Yup

 

[Timwis]

Must also say they are older mods

Maybe a bit of corrosion or/and e-liquid getting into the device via the 510 might be the cause but I am guessing!

 

[Mauritz55]

Maybe a bit of corrosion or/and e-liquid getting into the device via the 510 might be the cause but I am guessing!

The wire in mods do degrade or get hard after time And it will give higher resistance readings.
The coil itself can not jump from 0.80 to 1.0.
I normally calibrate my mods 2 times a year and also check my RTA’s and RDA’s post screws and 510 pin as this is the most overlooked part.However this is not the case here..are all these mods DNA/Yihi?Ive even seen this happen on Dicodes and found that the 510 is tarnished as some manufacturers use different Copper for their 510’s.
Buy a Tub of mother’s aluminum mag polish and with a Qtip polish it up to a luster

 

[Timwis]

The wire in mods do degrade or get hard after time And it will give higher resistance readings.
The coil itself can not jump from 0.80 to 1.0.
I normally calibrate my mods 2 times a year and also check my RTA’s and RDA’s post screws and 510 pin as this is the most overlooked part.However this is not the case here..are all these mods DNA/Yihi?Ive even seen this happen on Dicodes and found that the 510 is tarnished as some manufacturers use different Copper for their 510’s.
Buy a Tub of mother’s aluminum mag polish and with a Qtip polish it up to a luster

@Viper_SA say's they are old mods and going by pictures he has posted on the forum I don't think they have premium chipsets but maybe he will respond to confirm!

The coil itself can not jump from 0.80 to 1.0

that's why I asked if it was a bedded in build rather than checking resistance during doing the build because while doing a build it can easily jump around by these margins! Most times what the resistance is reading after installing my coil bares little resemblance to the resistance of my finished build and good to go!

 

[Viper_SA]

@Viper_SA say's they are old mods and going by pictures he has posted on the forum I don't think they have premium chipsets but maybe he will respond to confirm!



that's why I asked if it was a bedded in build rather than checking resistance during doing the build because while doing a build it can easily jump around by these margins! Most times what the resistance is reading after installing my coil bares little resemblance to the resistance of my finished build and good to go!

Correct @Timwis, they are not what would be considered HE at all and o DNA or Yi Hi or such chipsets. I'm apprehensive about polishing the 510 pins in the mods, unless it can safely be washed out with a quick spray with contact cleaner.

 

[charln]

It’s like some dark science, this resistance thing

I often see a variance between mods, for example when moving an atty with coils from one mod to another, without doing anything to the coils. And I’ve also seen a variance in atomisers, when I move a set of coils from one deck to another, using the same mod. I suspect it has to do with contact surfaces (screws, pins, etc) and conductivity differences, calibration, and possibly the way different mods read resistance. These variances are usually not large, and they are usually consistent and predictable.

In general there shouldn’t be variation of more than + 10% or - 10% from the stated spec. This provides more than enough margin for variation in the hardware, and some variation in the coils. Variation in actual coil resistance (compared to the stated resistance) is a result of leg length, and minor normal (acceptable) variations in the wire, and the building/wrapping process. Once a coil is bedded in, the resistance should not fluctuate much, if at all, and certainly not more than + or - 5%, if left in the same deck and same mod.
Out of interest, when installing a new coil, it is quite normal to see the starting resistance lower than spec, then drop further as it is being pulsed and bedded in, it can drop to almost 50% below spec, before eventually settling very close to the specified resistance.

This all applies to Nichrome wire, but for some alloys (like SS for example), the resistance of the coil will increase as the coil heats up, then decrease back to the specified resistance as it cools down.

 

[Stranger]

Most times what the resistance is reading after installing my coil bares little resemblance to the resistance of my finished build and good to go!

Could not agree more. I will use a calculator to try and give me some guideline and build accordingly and often when I first put it on the tab it will look way out. By the time you strum for hot spots, tighten screws, wick and bed in it has changed often very close to what the calc said. I find a variance of around 0.02 between my regulated mods. Mostly N80. I do find the comp wires to jump around quite a bit before they are bedded in.

If there is an enemy of chips, wires and anything electrical it is the heat up/cool down cycle

 

[Intuthu Kagesi]

With the coil testing I have been doing recently I have discovered that different chipsets and different mods all give slightly different resistances to the same coil in the same tank. The coils with stainless steel in them give way different readings but that is because SS's resistance changes depending on the temp of the wire.

But these tests are with our Ni80 Coils
DNA60 Stratum V7 - 0.46Ω
DNA60 IF Mods - 0.43Ω
DNA75C - 0.43Ω
YiYi 485J - 0.42
DNA100C - 0.43Ω
View attachment 238168

Outside of the fact that measurement of the decimals of an Ohm are challenging at best even in a laboratory environment with four wire sensing ...
Not all conductive materials are created equal, and as most tank and mod connectors are made of a mix of plated beryllium-copper or phosphor-bronze materials attached in turn to stainless steel with varying amounts of nickel as an alloy, attached in turn to other nickel alloy coils or mesh heating elements, all of whose emf limitations are far removed from that of copper, weeeeeell ... welcome to the world of thermally induced voltage errors, aka the thermocouple effect.
I think it's bloody amazing that mod manufacturers can and do measure anything below an ohm with even the most vague modicum of accuracy

 

[Intuthu Kagesi]

Thought I'd add share some more information on the challenges of resistance measurement below an ohm:

https://www.camiresearch.com/Campaigns/Web-Articles/4-wire-testing.html