Hello - Voltage question

[LukeDuke]

Hello. I'm a new member and pretty new to vaping. I'm getting the hang of things, but have a few questions.

I'm using a dual 18650 mod in wattage mode. While vaping and holding the fire button, my OHM sometimes changes by .01. Is this because the coil is heating up? The display only goes to .01 so I'm assuming it's also rounding up or down, right?

Also, the voltage changes some, usually no more than about .15 or so volts. Why does the voltage change while vaping? Does it change to keep the watts where I set them?

I haven't had a cigarette in 3 weeks!

Thanks in advance for your help.

Luke

 

[bombastinator]

Howdy and welcome

There are a few possibilities:
1.) you may have a TC wire in your coil cartridge such as stainless steel. TC wire changes resistance as it heats. That’s how the mod tells how hot the coil is for TC.
2.) Small consumer grade meters just aren’t as accurate as they read out. It may be fluctuation within the meter.
Either way the change is very small.

 

[LukeDuke]

Thank you for the reply. I should have mentioned that I am using kanthal. I googled it and it sounds like the resistance doesn't change much or at all with kanthal.

 

[Letitia]

Hello and welcome to ECF.
These small fluctuations aren't unusual. What brand and what batteries are you using? Where did you purchase them? It helps if you give us all the info, such as device, tank, and coil resistance, drop in or rebuildable, etc .

Congrats on the 3 weeks!!!

 

[LukeDuke]

Hello. I'm using two Sony VTC6 18650 3000mAh 15A batteries in an iJoy Shogun with a FreeMax Mesh Pro tank. I've been using .20 OHM double mesh Kanthal coils. I purchased everything from Element Vape.

The voltage fluctuates every time I vape. Once in a while the OHM will change no more than .01.

 

[Letitia]

Hello. I'm using two Sony VTC6 18650 3000mAh 15A batteries in an iJoy Shogun with a FreeMax Mesh Pro tank. I've been using .20 OHM double mesh Kanthal coils. I purchased everything from Element Vape.

Sounds like you're good. Where did you buy the batteries?

 

[LukeDuke]

I purchased the batteries from Element Vape as well.

 

[Letitia]

I purchased the batteries from Element Vape as well.

Hopefully they are authentic. It's safer to order your batteries from a battery vendor. I use Liion Wholesale for my batteries. The battery is the most important part of your setup. Have read any of Mooch or Batitude blogs posted here on ecf? Worth a read.

 

[LukeDuke]

I have not read any of their blogs, but I will right now. Thank you for the advice.

 

[greek mule]

Screw that coil tight into the tank,perhaps it makes not the proper connection.

 

[greek mule]

Does it change to keep the watts where I set them?

Exactly!

 

[Diver9543]

Hello and welcome to ECF. Congratulations on 3 weeks of no smoking. It sounds like you are on the right track.

 

[Ben Killeen]

My coils also change the resistance when they are new (first few burns to settle) and old (built up crap adds to resistance).
It’s quite normal.

If it changes dramatically like 0.2 or higher , then it’s possible loose connection or shorting out.

So small changes are fine

 

[sonicbomb]

Small changes in resistance in your case a hundredth of an ohm are normal and can be ignored. If the resistance is fluctuating by a few tenths of an ohm then it might be that your leads are not properly tightened.
The changes in voltage are the mod adjusting the balance of volts and amps being sent to the atomizer caused by this slight drift in resistance. This can also be ignored.

 

[BrotherBob]

Also, the voltage changes some, usually no more than about .15 or so volts. Why does the voltage change while vaping? Does it change to keep the watts where I set them?

Welcome and glad you joined.
Might like to read:
Calculating battery current draw for a regulated mod | E-Cigarette Forum
Index | E-Cigarette Forum
Best 18650 Battery Explanation!
Vape Battery Safety: Will You Marry Me? | Mt Baker Vapor
A Guide to Safe Charging - The Complete Guide to E-Cig Safety
Vaping 101: Battery Safety
7 Best Practices to Keep Your Charge

 

[Coyote628]

.01 is a very negligible difference. Nothing at all to be concerned about.

 

[Baditude]

The battery is the most important part of your setup. Have read any of Mooch or Batitude blogs posted here on ecf? Worth a read.

I have not read any of their blogs, but I will right now. Thank you for the advice.

Mooch's Battery Blog
Mooch's You Tube Channel
Baditude's Blogs

 

[Hawise]

Welcome, Luke. The ohmmeter (resistance-measuring-thingy) in a vape mod isn't really accurate to the final digit, so when it flops around by 0.01 it doesn't mean much of anything. It's just measurement inaccuracy. And you're right about the rounding, so a display change of 0.01 could mean as small a measured change as 0.001.

The volt issue is pretty much the same thing. A mod works like this:

• You set your watts
• The board in your mod reads the coil's resistance and calculates the voltage it needs to offer the coil to provide that wattage
• The board pulls energy from the battery, converts it into the appropriate form and passes it along to the coil

So whenever your resistance fluctuates, your voltage will too. The changes are small enough that they shouldn't affect your vape, so vape happy. You'll also see different voltages for different coils, but that's exactly what you want to see so it's nothing to worry about either.

@Letitia and @Baditude have suggested some great reading material, but here's a tip if you get into battery calculations: the voltage you usually see on your mod is not the same as your batteries' voltage (unless your mod displays that as well, as a few do). Mods usually display the voltage going to the coil, not coming from the battery. Since the board converts the energy as it passes it along, they're not the same.

Mooch's and Baditude's blogs are voluminous, to say the least, so here's my favourite place to start:

• Baditude's Battery Basics for Mods
• Mooch's Recommended Batteries Chart (which Baditude's post, above, will help you use effectively)

Congratulations on your first three weeks. May they be followed by many more!