Sub-Ohm Newbie Question

[Mden89]

I just ordered my first sub ohm kanger mini device. Ive been reading up quite a bit on the sub ohm gear and the rebuildables. Im quite familiar with the how to of the actual build and what not... but i cant find much on how much wattage certain resistance builds can handle. I am worried im going to blow up my device or ruin it by cranking my voltage up too high. I dont plan on getting into the rebuilding of the coils until i have a solid understanding of how to do this. For now i am really just trying to figure out how much my .5ohm resistance sub ohm atomizer can handle so when i get this bad boy in i can start vaping some nice clouds. A straight away answer would be ok, but i really would like some good information with depth to it. I like to know the insides and outsides of things. Not just the end product. Thanks everyone

 

[Susan~S]

What mod and tank are you using? If you are using the Kanger Subtank Mini it usually performs well between 20-35 watts on the 0.5Ω stock coil.

If you are using a regulated mod look at the specifications to see how low you can go as far as resistance. As far as how much wattage you use is trial & error. Start low and inch it up until you start to get a dry hit. Then back it down a notch or two.

 

[yuseffuhler]

I just ordered my first sub ohm kanger mini device. Ive been reading up quite a bit on the sub ohm gear and the rebuildables. Im quite familiar with the how to of the actual build and what not... but i cant find much on how much wattage certain resistance builds can handle. I am worried im going to blow up my device or ruin it by cranking my voltage up too high. I dont plan on getting into the rebuilding of the coils until i have a solid understanding of how to do this. For now i am really just trying to figure out how much my .5ohm resistance sub ohm atomizer can handle so when i get this bad boy in i can start vaping some nice clouds. A straight away answer would be ok, but i really would like some good information with depth to it. I like to know the insides and outsides of things. Not just the end product. Thanks everyone

As a general rule of thumb, just start low and work your way up. If it tastes like crap then it's too hIgh. What mod do you have?

 

[Lessifer]

It's not really the atomizer that you have to worry about blowing up, it's the batteries. You don't want to build such a low resistance that the mod is pulling more energy from the batteries than they can safely supply. I'm not familiar with that particular device, if it's a built in battery, check the specs for the amp limit, if it's one that you insert a battery into, make sure you get at least a 20 Amp battery, and read up on ohm's law.

Now, what would make a "good" vape is subjective, and you'll have fun exploring and tweaking for that.

 

[speedy_r6]

Wattage is a crap shoot. What works for some may not work for you. What works for you may not work for others. The best thing to do is just be sure your resistance isn't too low. After that, double check that your resistance isn't too low. After that, start out on a low wattage. If you don't like the amount of flavor/vapor you are getting, go up a little bit in wattage. Keep doing that until you find the sweet spot.

As Lessifer said, the biggest thing is being sure your resistance is high enough to not destroy the batteries. When they pop, bad things can happen.

 

[Mden89]

Wow! I am overwhelmed with the response from this community. First off, thank you so much everyone for such a quick reply. Forgive me if i am breaking any forum rules for posting this link, but this is the setup i ordered:

Authentic Kanger SUBOX Mini Black Starter Kit

I can see that it does come with the subtank mini. I just noticed now (unfortunately after i already ordered it) that it does not come with the 18650 cell. It says it requires a 20 amp or higher cell. Can someone provide me with some information about how Amps plays a role in the vaping? Or perhaps some literature so i may educate myself? Also, how does the ohms law play a part in this?

I would really like a solid understanding of how this all works from the ground up so i can be confident when i use the device, as well as when i decide to build in the future. I want an understanding so solid i could educate friends and family who have questions. I figured this forum was a good place to start. Any links and/or information would be greatly appreciated.

 

[Mden89]

It's not really the atomizer that you have to worry about blowing up, it's the batteries. You don't want to build such a low resistance that the mod is pulling more energy from the batteries than they can safely supply. I'm not familiar with that particular device, if it's a built in battery, check the specs for the amp limit, if it's one that you insert a battery into, make sure you get at least a 20 Amp battery, and read up on ohm's law.

Now, what would make a "good" vape is subjective, and you'll have fun exploring and tweaking for that.

So the ohms refers to the amount of resistance thats provided between the battery and the coils? Greater resistance means less draw from the battery? Less resistance means a greater draw from the battery?

 

[ElevenEleven]

So the ohms refers to the amount of resistance thats provided between the battery and the coils? Greater resistance means less draw from the battery? Less resistance means a greater draw from the battery?

Ohms refer to the resistance of your atomizer. Your resistance draws volts from your batteries. Amps are the threshold of your batteries. Everything else you've said is correct.

 

[Mden89]

Ohms refer to the resistance of your atomizer. Your resistance draws volts from your batteries. Amps are the threshold of your batteries. Everything else you've said is correct.

Thanks Brandon. Ive been looking for a battery for the device i ordered and found this one, but i cannot figure out for the life of me how many Amps it can handle. Can you explain how i figure this out?

Amazon.com: 2pcs 18650 Panasonic NCR18650B Cell 3400mAh Rechargeable Li-ion Battery: Electronics

 

[speedy_r6]

The amp rating is the maximum amperage it can safely discharge at. If you exceed this, you risk the battery blowing up.

Amps = volts / resistance, or watts / volts = amps. The 18650 are roughly 4.2v when fully charged, and that goes down as it is used. This is typically more of an issue for mechanical mods that are pulling whatever voltage the battery is at. Since yours is regulated and it is going to draw as much power needed and then step it up or down to the proper voltage for the coil, I would think you would have to rely more on the watts/battery voltage=amps rule. Typically, a battery is deemed fully discharged at 2.7v, but it isn't uncommon for low voltage cutoffs to be well above that(innokin is at 3.3v). If we assume the battery is feeding 3 volts and you are pulling all 60 watts, that means you are pulling 60/3=20 amps, hence why you need at least a 20 amp battery. At the same time, if your battery is freshly charged and pushing 4.2 volts and you are running at a full 60 watts, you are drawing 14.28 amps(well under the 20 amp limit of the battery).

For those with a mechanical mod, the amps=volts/resistance is much more important. Theirs just puts whatever voltage the battery is at into the coil. Based on that, if someone is using a fully chaged battery(4.2volts) battery rated for 20amp discharge on a 0.2 ohm coil, this would be the equation: 4.2v / 0.2ohm = 21amps. As you can see, that would be exceeding the safe discharge limit for the battery, and could possibly cause the battery to fail and explode.

 

[ElevenEleven]

Thanks Brandon. Ive been looking for a battery for the device i ordered and found this one, but i cannot figure out for the life of me how many Amps it can handle. Can you explain how i figure this out?

Amazon.com: 2pcs 18650 Panasonic NCR18650B Cell 3400mAh Rechargeable Li-ion Battery: Electronics

You're looking for something called CDR (continuous discharge rate). Also, NCR batts are not good for this type of application. Their amperage is very low, usually ~5 amps.

 

[Mden89]

The amp rating is the maximum amperage it can safely discharge at. If you exceed this, you risk the battery blowing up.

Amps = volts / resistance, or watts / volts = amps. The 18650 are roughly 4.2v when fully charged, and that goes down as it is used. This is typically more of an issue for mechanical mods that are pulling whatever voltage the battery is at. Since yours is regulated and it is going to draw as much power needed and then step it up or down to the proper voltage for the coil, I would think you would have to rely more on the watts/battery voltage=amps rule. Typically, a battery is deemed fully discharged at 2.7v, but it isn't uncommon for low voltage cutoffs to be well above that(innokin is at 3.3v). If we assume the battery is feeding 3 volts and you are pulling all 60 watts, that means you are pulling 60/3=20 amps, hence why you need at least a 20 amp battery. At the same time, if your battery is freshly charged and pushing 4.2 volts and you are running at a full 60 watts, you are drawing 14.28 amps(well under the 20 amp limit of the battery).

For those with a mechanical mod, the amps=volts/resistance is much more important. Theirs just puts whatever voltage the battery is at into the coil. Based on that, if someone is using a fully chaged battery(4.2volts) battery rated for 20amp discharge on a 0.2 ohm coil, this would be the equation: 4.2v / 0.2ohm = 21amps. As you can see, that would be exceeding the safe discharge limit for the battery, and could possibly cause the battery to fail and explode.

Thank you for the thorough explanation Speedy. Just to make sure i understand: With the Eleaf stick and nautilus mini i have right now, if i run it at 3.8V on a 1.8ohm atomizer i am pulling 2.1 amps? That seems ridiculously low... But this is a significantly lower power setup than what i ordered i suppose

 

[Mden89]

You're looking for something called CDR (continuous discharge rate). Also, NCR batts are not good for this type of application. Their amperage is very low, usually ~5 amps.

What type of 18650 battery should i be looking for?

 

[speedy_r6]

Those batteries are listed as having:

9. Continuous Discharging Current (Max.): 4.87A (0~ +40°C)

I would take that to mean that they are only able to deliver 4.87 amps continuously and not be anywhere close to safe.

 

[Mden89]

Oh so no fancy mathematics are needed to find out what amps the battery can handle? I can just look directly at the CDR and that will tell me what it can handle at a maximum discharge. An absolute max...

 

[Mooch]

Thanks Brandon. Ive been looking for a battery for the device i ordered and found this one, but i cannot figure out for the life of me how many Amps it can handle. Can you explain how i figure this out?

Amazon.com: 2pcs 18650 Panasonic NCR18650B Cell 3400mAh Rechargeable Li-ion Battery: Electronics

Often the seller lists the maximum continuous discharge, in amps, that the cell can handle. It's often abbreviated to CDR, continuous discharge rate. But, there are a lot of exaggerated ratings out there so if you're not totally sure, ask us.

The NCR18650B is a fantastic cell but its CDR is about 6.4A, based on its datasheet having graphs for discharges up to 2C. It starts getting pretty warm at 5A though. Sometimes the only way to find out a cell's CDR is to look up the ratings on the cell's datasheet. There are a few lists of cell CDRs here on ECF though, much easier to find.

[edit] oops, others beat me to the punch

 

[Mden89]

Yeah Id really like to find a suitable battery for what i purchased. Where can i start looking?

 

[ElevenEleven]

What type of 18650 battery should i be looking for?

Unprotected IMR/INR

AW IMR
AW IMR 18650 2200 mAh

Samsung 25R
18650 Samsung INR18650-25R 2500mAh High Discharge FLAT Top - Batteries - Batteries, Chargers, and PowerPax Carriers

 

[Mden89]

Unprotected IMR/INR

AW IMR
AW IMR 18650 2200 mAh

Samsung 25R
18650 Samsung INR18650-25R 2500mAh High Discharge FLAT Top - Batteries - Batteries, Chargers, and PowerPax Carriers

Awesome thanks again Brandon. Will these types of batteries charge inside the Kanger mini box i purchased if i plug the mini usb into it? Or will i have to purchase a third party charging device for the cell to charge

 

[ElevenEleven]

Awesome thanks again Brandon. Will these types of batteries charge inside the Kanger mini box i purchased if i plug the mini usb into it? Or will i have to purchase a third party charging device for the cell to charge

Well, I don't know much about the mod except what it looks like, but I know that its best to charge batteries with an external charger.