Resistance changing in a coil?

[goalie]

I’m very new to coils. I was vaping today and noticed my coil was really glowing.. I thought something was wrong, so I took it apart and everything looked ok. I did a resistance reading and it had dropped from .33 to .18. Is something wrong or does the resistance of a coil sometimes change? I think it was glowing due to the wattage being too high for the “new” resistance of the coil.

Thanks

 

[stols001]

Are you talking about a drop in coil or RTA/rba deal? I'm assuming the latter. What is the coil material and what wattage are you running it at. Stainless steel will fluctuate in resistance somewhat, and if you took your first (and only) reading when it was cold, vs. glowing red, I could perhaps see such a drastic coil change. The resistance changes in temp controlled wires are actually used to regulate temperature is my understanding, and they all fluctuate differently. Kanthal does not do that, to my understanding.

That type of resistance change may be within normal for a SS coil, but not a kanthal one (I am assuming you are running in wattage mode. If so, it's not something you need to worry about (although I guess it is telling you that your temperature is rising in your tank, if you see that much of a drastic change).

What wattage were you running that was "too high" for the coil? Did you notice any other changes? If you can, check to make sure the legs are still securely mounted to the posts and that nothing is loose. Otherwise, I'd be guessing it's a cold stainless steel coil, who's resistance is jumping around a bit more than normal if you superheated it.

Again, I'm speculating at this point, because really more information is needed.

Anna

 

[goalie]

65W. I’m reading it while its mounted in the pharaoh. Its SS. My first and only reading was when I just installed it and never lit it up. I’ve had it in for about a day and a half and noticed it really glowing a bit ago, took it off and took a reading and it really dropped. If its normal, should I regularly take readings of the resistance?

 

[stols001]

It sounds within the realm of normal to me. In wattage mode you don't have to worry about it. If using temperature control mode, most mods will have you enter the resistance when it's cold, and will ask about if it's a new coil or not going into TC or if replacing batteries. If it's not a new coil, then just enter no, and the resistance is kept at the "cold" resistance. IDK, it seems like a larger fluctuation but not necessarily something you need to worry about if all else is well, and if you read it when you coiled and installed it, that will likely be its lowest resistance. However, I think some folks use the resistance after they heat it and check it for hot spots, as often times, the resistance will be a hair lower than wire that has never been heated. Again, this is to the best of my knowledge, but yes, my SS coils resistance changes when heated the first time, and then again when hot. As long as it's approximately the same resistance when it's not hot, I'm not sure that you have anything to worry about.

Anna

 

[Baditude]

I was vaping today and noticed my coil was really glowing.. I thought something was wrong, so I took it apart and everything looked ok. I did a resistance reading and it had dropped from .33 to .18. Is something wrong or does the resistance of a coil sometimes change? I think it was glowing due to the wattage being too high for the “new” resistance of the coil.

In my experience, as coils age their resistance increases. Partially due to the unvaporized sugars that accumulate from the e-liquid, and general breakdown of the wire.

The only time I have seen resistance drop was when one of the RDA post screws became loose. My vape had suddenly become VERY HOT. I knew something was wrong with the coil and measured the atomizer on an ohm reader.

The resistance had fallen from 0.6 ohm to 0.1 ohm. Wondering how and why this happened, I checked the post screws and one was loose. Tightened the screw and rechecked the resistance and I was back to 0.6 ohm.

The fact that you noticed that your coil was glowing extremely bright makes me wonder if you had a "hot spot" or short in your coil.

 

[AzPlumber]

As bad pointed out, I also suspect a hot spot or a short. Could be the coil itself or the coil touching a post, atomizer base or cap.

 

[goalie]

I love this place. Thanks for the videos. I'll watch them tonight and educate myself a bit more. Running coils is s bit more complicated than I thought.


Sent from my iPhone using Tapatalk Pro

 

[goalie]

I did switch my SS one with a kanthal one. I had picked up some cheap pre-made SS ones and I guess you do get what you paid for.. going to try a kanthal one now and see how it works.. its a clapton coil and it looks heftier so I'm hoping it holds up better.

 

[classwife]

The second video...
Please note the he is using silica wick which will not burn...if you are using cotton or rayon check your build without the wick in there.



Edit to add....moved this to Coil Builds from APV Mods Discussion

 

[MacTechVpr]

In my experience, as coils age their resistance increases. Partially due to the unvaporized sugars that accumulate from the e-liquid, and general breakdown of the wire.

The only time I have seen resistance drop was when one of the RDA post screws became loose. My vape had suddenly become VERY HOT. I knew something was wrong with the coil and measured the atomizer on an ohm reader.

The resistance had fallen from 0.6 ohm to 0.1 ohm. Wondering how and why this happened, I checked the post screws and one was loose. Tightened the screw and rechecked the resistance and I was back to 0.6 ohm.

The fact that you noticed that your coil was glowing extremely bright makes me wonder if you had a "hot spot" or short in your coil.

No question, if you're seeing it go into the red zone visible spectrum in normal ambient light and wetted, you've got a short IMO. The exception being lost wick contact and of course, loose connections.

It's not unusual to see a poor connection precipitate persistent arcing in a badly configured or oriented coil.

Uneven separation (asymmetry) with close contact is not our friend. Forum search…arcing. Whole purpose for testing resistance is to ensure we're not running Ω less than appropriate for wire length.

Set the watts/temp and run is sham. Murphy rules.

But it's helpful to have that first loose connection experience to know better…what a bad vape feels and tastes like.

We all know that, don't we?

Good luck.

IMG_1070a

• MacTechVpr
• Jun 1, 2015

Tehnsioned Contact Micro Coil, MacTechVpr