Don't forget about Watts Law

[suprtrkr]

Haha I know I'm getting picky, it's just kind of a pet peeve of mine that people preach the importance of it without actually fully understanding it themselves, it just worries me that some new vaper gets told to worry about ohms law, and if they actually follow that correctly they're going to assume that resistance is the only thing that matters in every scenario

You are certainly correct it happens in practice. I catch it all the time. People will PM me to ask if this or that resistance is safe to fire on their sigelei 150 or whatever. I will explain to them how to calculate the battery draw on a regulated, and usually link them to @Mooch 's blog on the subject: Calculating battery current draw for a regulated mod | E-Cigarette Forum

But, y'know what? Given they PM'd and asked, I have done my job. They got worried, engaged brain before pushing fire button and, when they couldn't figure it out, were smart enough to ask. That's victory

 

[Robert Cromwell]

you are putting way to much faith in chips that can't even do step down as they rely on the cell to decide what they can run

many chips do step down and many more pulse the DC voltage if below the battery voltage to control the wattage applied to the coil.

 

[NancyR]

many chips do step down and many more pulse the DC voltage if below the battery voltage to control the wattage applied to the coil.

but more don't than do

 

[Dlmdavid]

you are putting way to much faith in chips that can't even do step down as they rely on the cell to decide what they can run

if the chip fails the device won't fire, the batteries don't hook direct like a mech mod, like I said two seperate circuits. Sure the chip can short and cause battery failure but that's unavoidable

 

[NancyR]

if the chip fails the device won't fire, the batteries don't hook direct like a mech mod, like I said two seperate circuits. Sure the chip can short and cause battery failure but that's unavoidable

I am not talking about a chip that fails I am talking about ones that instead of doing proper step down act like a mech in not allowing the device to go lower than the voltage in the cells.

 

[Robert Cromwell]

but more don't than do

Very few will not at least pulse the DC output voltage to control the wattage applied to the coil.
the iStick 20 is one that comes to mind that does not output below battery voltage. The iStick 30 however will vape at very low wattages nicely. So will most newer mods. Usually by what is commonly known as PWM.

 

[suprtrkr]

Which is a reason I like mods that display the current. such as the VTC mini.
Although I am not sure if that is battery or output current.

It's gotta be output, doesn't it? How on Earth could a board measure it's own losses to determine battery current?

 

[Dlmdavid]

I am not talking about a chip that fails I am talking about ones that instead of doing proper step down act like a mech in not allowing the device to go lower than the voltage in the cells.

I still don't understand how that would make resistance all of a sudden factor into the equation, it doesn't matter if the chip is any good or not, it's seperating the circuits

 

[NancyR]

I still don't understand how that would make resistance all of a sudden factor into the equation, it doesn't matter if the chip is any good or not, it's seperating the circuits

When you are a low wattage vaper and the device does not allow voltage lower than the cell voltage you need a higher ohm to reach the proper output for what you vape, as low ohm and no step down means the watts set doesn't matter as the device will run what it runs no matter how you have it set if you want what is under the cell voltage

 

[crxess]

but more don't than do

But more and more are incorporating per customer demand.
Might check new releases.

High power Mod demand pushed Buck aside.......................until Low power Vapers decided they needed the High power mods.
Made since to me....., not, however it is good to see Manufacturers do listen.

 

[Dlmdavid]

When you are a low wattage vaper and the device does not allow voltage lower than the cell voltage you need a higher ohm to reach the proper output for what you vape, as low ohm and no step down means the watts set doesn't matter as the device will run what it runs no matter how you have it set if you want what is under the cell voltage

Still has nothing to do with the battery, I did agree that resistance makes a difference on the device, in this case allowing it to work, but it still has zero effect on your actual battery draw which is what everyone needs to worry about to be safe.

 

[mountaingal]

All of this is why I am just a tootle puffer and rarely ever go over 18W. I am a well-educated person and given the need, I could figure all those calculations out. I build my own coils (sometimes lower then 1W), make my own juice, and really enjoy those aspects of vaping. I trust my regulated mods. In 4+ years, I have never had a battery problem. But, I like reading all these well thought-out posts, it is great to see vapers helping vapers. Thanks for the education.

 

[defdock]

I still don't see the correlation.

If a regulated mod does not require the resistance to pull X amount of power, why does my istick30 die after 2 tanks at 30w on .6 resistance coils but can last as far as 8 tanks at the same wattage?

I really don't understand

 

[Dlmdavid]

I still don't see the correlation.

If a regulated mod does not require the resistance to pull X amount of power, why does my istick30 die after 2 tanks at 30w on .6 resistance coils but can last as far as 8 tanks at the same wattage?

I really don't understand

Your tanks will burn different amounts of juice at different resistances, also Im talking about devices with external batteries, there might be something different with a device like the istick 30 with internal batteries, but I doubt it

 

[defdock]

But you can see the confusion. Regardless, when the coil is lower ohm (higher watts while still being close to battery nominal level for less stress) it kills the battery faster.

Chip efficiency? If a chip is less efficient working at battery nominal voltage, there is a huge problem.

 

[sparkky1]

you are putting way to much faith in chips that can't even do step down as they rely on the cell to decide what they can run

Perhaps you should try one of these Innokin iTaste MVP 20 Watt Box Mod

 

[suprtrkr]

I still don't see the correlation.

If a regulated mod does not require the resistance to pull X amount of power, why does my istick30 die after 2 tanks at 30w on .6 resistance coils but can last as far as 8 tanks at the same wattage?

I really don't understand

Because watts applied to the atty are not the same as watt/seconds (or joules) drawn from the battery. As ohms increase downstream of the board, so must voltage to make the same watts. As voltage increases downstream of the board, current must increase upstream of the board because battery voltage is (semi) fixed by charge state. And the faster current drawn from the battery increases, the faster it empties.

 

[NancyR]

Perhaps you should try one of these Innokin iTaste MVP 20 Watt Box Mod

I actually had one and hated it as I dislike any device that doesn't give me a DC output and I can tell the difference in the vape, starting with the coolfire 4 the disrupter and the mvp 3.0 pro they have the output I enjoy, but so does my P3

 

[defdock]

Which still require a resistance for the math to apply and find amount of current required.

Honestly your making it more confusing.

 

[daviedog]

Can you get Watts law without Ohms law?.
Watt is the wood thing your mod is resting on? Crossbow?..