Does Wattage Really Affect Mechanicals?

[shurpacabra]

For sake of example, lets say that I have a setup with a 30A 18650 2100mAh 3.7V battery. Lets also say that my rda is clocking in at .2 Ohms. We are going to use 4.2 Volts here and assume the battery is fully charged.

This would mean that I am pushing 88 Watts. Sounds crazy (and I've read of people doing crazier!).

However, this would mean that I am only pushing 21A (4.2V / .2 Ohms = 21A) which is well under my 30A limit.

In this hypothetical, would it be safe to vape? The wattage seems insanely high, but is it really a factor here as long as I stay under my amperage limit?

 

[Baditude]

One should also factor in the accuracy of the ohm reader/digital multimeter and the possibility of human error. It's true that a 0.2 ohm coil will pull 21 amps from the battery. However, if you are off by just 0.1 ohm in your reading, you'll be pulling 42 amps from the battery which is obviously way over the amp limit of a 30 amp battery.

0.0 ohm is a dead short, which will send ANY battery into thermal runaway.

 

[shurpacabra]

WHOAAA what am I looking at? Is that really the post?!

Assuming that the calculations are correct, it would be considered "safe" though? (I would never assume calculations are correct, but for sake of the example)

 

[edyle]

For sake of example, lets say that I have a setup with a 30A 18650 2100mAh 3.7V battery. Lets also say that my rda is clocking in at .2 Ohms. We are going to use 4.2 Volts here and assume the battery is fully charged.

This would mean that I am pushing 88 Watts. Sounds crazy (and I've read of people doing crazier!).

However, this would mean that I am only pushing 21A (4.2V / .2 Ohms = 21A) which is well under my 30A limit.

In this hypothetical, would it be safe to vape? The wattage seems insanely high, but is it really a factor here as long as I stay under my amperage limit?

1: I suppose the short answer has to be no. It is not safe.
2: A manufacturer doesn't rate a battery for 30A because it is safe at 30A. He rates it at 30A because it is capable of 30A. Maybe the uselife life of the battery shortens tenfold as a result, but can still do the 30A.
3: I do not understand what the question in the topic really is.

 

[shurpacabra]

The fact that this scenario (I considered building a .2 ohm coil) makes the wattage of my mechanical rise to 88 is pretty damn scary to me. So I guess my question is... does the wattage really even matter? Remaining significantly below your battery's rated amp limit is what's most important right? I mean, the battery is, I would say, the most important part of a mechanical.

Basically, if we can say with certainty that your amperage is below the max rating, would the wattage make any difference whatsoever?

edit - would a really high wattage make your mod more dangerous as long as you remain within your amp limit?

 

[WattWick]

Batteries degrade over time and with usage. The more stress you put on it, the quicker it degrades. A 30A battery that pushes 20+ amps each and every time the button is pushed will not remain a 30A battery very long.

 

[Baditude]

WHOAAA what am I looking at? Is that really the post?!

Assuming that the calculations are correct, it would be considered "safe" though? (I would never assume calculations are correct, but for sake of the example)

You are looking at an IMR battery which went into thermal runaway. The inner contents have exploded out of the battery casing. Imagine this occuring in your mechanical mod. Literally a metal pipe bomb. Hence the precautions for safety, especially when sub-ohming with a mechanical mod.

To answer your question. Sub ohm vaping is dangerous with calculated risks known & accepted. Not my style of vaping. I chose to vape for health reasons, not to make OMG! vapor clouds.

Cloud Chasing is Dangerous

 

[John_]

For sake of example, lets say that I have a setup with a 30A 18650 2100mAh 3.7V battery. Lets also say that my RDA is clocking in at .2 Ohms. We are going to use 4.2 Volts here and assume the battery is fully charged.

This would mean that I am pushing 88 Watts. Sounds crazy (and I've read of people doing crazier!).

However, this would mean that I am only pushing 21A (4.2V / .2 Ohms = 21A) which is well under my 30A limit.

In this hypothetical, would it be safe to vape? The wattage seems insanely high, but is it really a factor here as long as I stay under my amperage limit?

You want your power source to have a significantly higher current limit than what you need. You should never go above 80% of the cell's current limit. The more current you draw from a battery the higher the chance of it failing, while this could be a simple fizzle it could also vent pretty badly and release all sorts of fumes that humans ought not to breath in. If these batteries were off in an enclosure far away from sensitive parts of your body (face, lips, hands, etc...) then running them at their limit would be relatively safe. Since we are running these so close us, you want to be extremely careful and not tax that battery. Yes high current limits are necessary but not because we need that much current.

 

[shurpacabra]

That's crazy Baditude, hope that thing didn't get you!

I also don't want anyone to think I'm just doing this like an idiot. This is why I am coming to people more experienced than myself to learn before attempting... or even considering attempting.

 

[edyle]

The fact that this scenario (I considered building a .2 ohm coil) makes the wattage of my mechanical rise to 88 is pretty damn scary to me. So I guess my question is... does the wattage really even matter? Remaining significantly below your battery's rated amp limit is what's most important right? I mean, the battery is, I would say, the most important part of a mechanical.

Basically, if we can say with certainty that your amperage is below the max rating, would the wattage make any difference whatsoever?

edit - would a really high wattage make your mod more dangerous as long as you remain within your amp limit?

Well either look at the wattage or the amps - in this case the amps seems more usefull because you are looking at a battery rated at 30amps.

10% - 3 amps is going to be absolutely safe; like driving at 10 miles per hour when you know your car can run at 100 mph.
50% - 15 amps is going to be - well - highway cruising speed? like 50 mph on the highway.

 

[shurpacabra]

10% - 3 amps is going to be absolutely safe; like driving at 10 miles per hour when you know your car can run at 100 mph.
50% - 15 amps is going to be - well - highway cruising speed? like 50 mph on the highway.

That actually puts it into perspective quite well, thanks.

I just did the math on the wattage and was concerned. When you're used to VV/VW devices even 10 and 12 watts seems high, so when I saw 88 I got a little freaked!

 

[Baditude]

That's crazy Baditude, hope that thing didn't get you!

I also don't want anyone to think I'm just doing this like an idiot. This is why I am coming to people more experienced than myself to learn before attempting... or even considering attempting.

I appreciate you asking questions before jumping into the deep end of the pool before you've learned to swim.

That luckily was not my battery in the pic. However, I did experience a battery explode in my first mechanical mod when the fire switch became stuck in the on position. This experience nudged me to learn about batteries and battery safety. Below is the battery which exploded on me. Being an ICR battery, it vented hot gas and flames and nearly caused a fire.

 

[shurpacabra]

Ah man that can't be fun. I will be sure to avoid those like the plague. I feel like I read about people saying not to get those actually... it was basically anything with the word "fire" in it like UltraFire and TrustFire and whatnot.

 

[edyle]

That actually puts it into perspective quite well, thanks.

I just did the math on the wattage and was concerned. When you're used to VV/VW devices even 10 and 12 watts seems high, so when I saw 88 I got a little freaked!

If you really want to know what power you're vaping at on a dripper you got to measure the actual voltage accross the coil - under load.

You noload voltage might be 4.2 volts coming from the battery, but when you put on a low ohm coil it might only be 3 volts.

That's another headsup to look for btw; when you see a big voltage drop it tells you that you are pushing it.
I'd say a 10% voltage drop is in the safe zone; or the comfort zone. (Actually 1% I'd qualify as "safe")

 

[tj99959]

To begine with your fully charged 4.2v battery isn't going to provide 4.2v under load. So you probably don't need to worry about 88 watts, it ain't gonna happen with a mechanical. 72 watts is the highest I've been able to make a mechanical actully produce with a .2 ohm coil, (for one hit) and that was with a copper mod with solid silver pins, and MNKE 30a/60a battery.

Next I would point out that making a .2 ohm coil isn't as easy as one would think. Not hard to make a .2 +/-.05 ohm coil, but that's a huge spread when you are down that low.

My experience with those kind of builds is to say "well gee that was fun", and then pick up a PV with a more normal build on it to have a vape.
Also, you'll need to buy your juice in larger containers, cuz' you're gonna need it. And, if you try to vape your normal juice, (nicotine) it will knock you on your can.

 

[shurpacabra]

Well I got my multimeter yesterday afternoon. I rebuilt my RDA with four 1/16" coils at 6 wraps each (making it a 6/7 wrap I believe?). I did some tests and found that the resistance of my leads is .5 ohms. The resistance of my atty was bouncing between 1.1 and 1.2, making my total resistance about .6 or .7 which I would say is accepted as a "safe" range. I am using an Efest 35A 18650 2500mAh so no issues there. I'm glad I can finally see the numbers on a screen and feel much better about what I'm doing. Being able to test your battery and charge at the ideal moment is also a huge plus. Thanks for all the help guys.

Also, you'll need to buy your juice in larger containers, cuz' you're gonna need it. And, if you try to vape your normal juice, (nicotine) it will knock you on your can.

Yes I have noticed this haha. I'm using crazy amounts of juice. I was prepared for the fact that my hits are WAY bigger though, so I'm vaping around 6mg as opposed to my normal 12. Still gives me a slight buzz every now and again when I get a good one.