Confusion with voltage output for box mods

[Daz123]

Dear Fellow Vapers,

Looking at the online ohm calculators, when you plug in a resistance of 0.2 ohms and a power of 180W you get a discharge of 6V and a current of 30A. I'm confused because I thought batteries could only fire up to 4.2V when fully charged (that's what most specifications say for 18650 batteries). Could anyone clear up this confusion?

Regards,

Daz

 

[mauricem00]

Dear Fellow Vapers,

Looking at the online ohm calculators, when you plug in a resistance of 0.2 ohms and a power of 180W you get a discharge of 6V and a current of 30A. I'm confused because I thought batteries could only fire up to 4.2V when fully charged (that's what most specifications say for 18650 batteries). Could anyone clear up this confusion?

Regards,

Daz

that is true for a mechanical mod and under load the voltage is lower than that but a regulated mod is able to boost voltage. my regulated mod will go up to 84 volts on a single battery I think you should learn more about mods and batteries before you try building coils that low or vaping at high power levels. that kind of "cloud chasing" is pushing the limits of your batteries and can be dangerous if you are not a well educated advanced vaper.welcome to ECF. you will find many people here who are happy to help you and answer any questions you have

 

[Susan~S]

Hello and welcome to the forum @Daz123. Glad to have you here!

The 4.2 voltage limitation only applies when talking about using the battery in a mechanical mod.

With a regulated mod basically the chip in your variable v/w mod takes in power from the battery and stores it in a capacitor. When the stored energy reaches the potential (voltage) it dumps out to the atty.

DC Boost Converter
Buck-Boost Converter

A good example would be a dimmer switch.
____

When using a regulated mod, the best way to determine how many amps you will need/be drawing (at min battery voltage) is to use the max wattage you plan on vaping at and follow this guide by @Mooch.

• Calculating Battery Current Draw for a Regulated Mod

 

[edyle]

Dear Fellow Vapers,

Looking at the online ohm calculators, when you plug in a resistance of 0.2 ohms and a power of 180W you get a discharge of 6V and a current of 30A. I'm confused because I thought batteries could only fire up to 4.2V when fully charged (that's what most specifications say for 18650 batteries). Could anyone clear up this confusion?

Regards,

Daz

The battery voltage is between 3.2 and 4.2 volts.
the mod takes power from the battery and outputs at a different voltage.

If you have a dual battery mod with 2 batteries in series, the voltage of the batteries together is 6 to 8 volts to begin with.
A triple battery mod with batts in series is starting with 9 to 12 volts.

 

[Daz123]

Thanks kindly for the fast responses guys!, really appreciate the info you've given me, cleared up my confusion!. I'm looking to buy an rx200 (triple 18650 mod) with a sapor or velocity rda. How do amps take play in regulated vw mods? does having three batteries triple my continuous amperage so say if i have 3 x 20A batteries would that be a total of 60A? (sorry I'm not as good as I used to be back in high school with circuits, ohm's law, etc.)

 

[mauricem00]

Hello and welcome to the forum @Daz123. Glad to have you here!

The 4.2 voltage limitation only applies when talking about using the battery in a mechanical mod.

With a regulated mod basically the chip in your variable v/w mod takes in power from the battery and stores it in a capacitor. When the stored energy reaches the potential (voltage) it dumps out to the atty.

DC Boost Converter
Buck-Boost Converter

A good example would be a dimmer switch.
____

When using a regulated mod, the best way to determine how many amps you will need/be drawing (at min battery voltage) is to use the max wattage you plan on vaping at and follow this guide by @Mooch.

• Calculating Battery Current Draw for a Regulated Mod

I hate to nit pick but in the converter the energy is stored in an inductor not a capacitor. a small capacitor is used on the output to average out the voltage spikes.sorry but my EE training at the university make me cringe at these kind of errors.and being a grumpy old man I had to correct it

 

[edyle]

Thanks kindly for the fast responses guys!, really appreciate the info you've given me, cleared up my confusion!. I'm looking to buy an rx200 (triple 18650 mod) with a sapor or velocity rda. How do amps take play in regulated vw mods? does having three batteries triple my continuous amperage so say if i have 3 x 20A batteries would that be a total of 60A? (sorry I'm not as good as I used to be back in high school with circuits, ohm's law, etc.)

With regulated mods it's better to just think in terms of wattage.

At 200 watts you'd need to get 67 watts from each of the three batteries.

 

[Susan~S]

I hate to nit pick but in the converter the energy is stored in an inductor not a capacitor. a small capacitor is used on the output to average out the voltage spikes.sorry but my EE training at the university make me cringe at these kind of errors.and being a grumpy old man I had to correct it

No problem, I take heed when corrected.

From the first link:

"A boost converter (step-up converter) is a DC-to-DC power converter with an output voltage greater than its input voltage. It is a class of switched-mode power supply (SMPS) containing at least two semiconductors (a diode and a transistor) and at least one energy storage element, a capacitor, inductor, or the two in combination. Filters made of capacitors (sometimes in combination with inductors) are normally added to the output of the converter to reduce output voltage ripple."

So with our chips is it just an inductor or is it both? Feel free to educate me.

 

[Daz123]

Thanks edyle!

Just to clarify, and I apologize for these stupid questions, but is there ever a wattage thats too high for a build?, like if im running a 0.05ohm build at 200W what would happen? would it be safe?

And no, I'm not thinking of doing this, just want to gain a better understanding lol.

 

[speedy_r6]

Thanks kindly for the fast responses guys!, really appreciate the info you've given me, cleared up my confusion!. I'm looking to buy an rx200 (triple 18650 mod) with a sapor or velocity rda. How do amps take play in regulated vw mods? does having three batteries triple my continuous amperage so say if i have 3 x 20A batteries would that be a total of 60A? (sorry I'm not as good as I used to be back in high school with circuits, ohm's law, etc.)

With a regulated mod, you can say you have however many times the amp limit as batteries. 2 batteries doubles it. Three triples it. Four makes it times 4. You get it. To calculate amp draw, use the cutoff voltage of ~3.2v per cell. Divide your watts by 3.2, and that tells you the total amps. If we say 192 watts divided by 3.2, that would equal 60 amps being drawn. If you have 3 batteries, that 60 is equally spread across all three, meaning 20a per cell.

Clear as mud, right?

 

[Susan~S]

Just to clarify, and I apologize for these stupid questions, but is there ever a wattage thats too high for a build?, like if im running a 0.05ohm build at 200W what would happen? would it be safe?

Read the link I posted.

• Calculating Battery Current Draw for a Regulated Mod

More About Batteries

There are only a few battery manufacturers in the world who make their own "cells", including LG, Samsung, Sony, Panasonic & Sanyo.

All the other brands on the market buy the second and third tier cells from those manufacturers and re-wrap them under their own brand. These are "second and/or third tier cells" which did not meet the higher standards of the original manufacturer. In order to compete with the original manufacturers' batteries (first tier), these other companies feel obligated to publish specifications which are inflated to make them appear superior to those of the original manufacturer.

* (AW is Andrew Wan, a former Panasonic employee who branched out to create his own "brand" of batteries. He allegedly has agreements with the major cell manufacturers to purchase first tier batteries from them. Not all batteries are created equal, so AW tests these batteries for quality. The best get chosen to be AW brand, and are re-wrapped as AW.)

Do your research before you buy. Decide what battery to buy depending upon the application that you will use them.

Here are links to some of Mooch's other battery blogs:

• Mooch's Recommended Batteries
  
• There are no 18650 batteries with a genuine rating over 30A!
• Battery pulse ratings are useless!
• 18650 Safety Grades -- Picking a Safe Battery to Vape With
• List of My Battery Tests

BATTERIES - WHERE TO BUY

Only buy batteries from a reputable supplier (not ebay or Amazon) as there are many counterfeit batteries being sold. Here are several reputable battery suppliers in the US.

• RTD Vapor
• Illumination Supply
• Orbtronics
• IMR Batteries
• Liion Wholesale

 

[Daz123]

Thanks Susan!, so if i read that post correctly, an rx200 at 200W would draw 67W of power from each battery. with a minimum voltage of 3V per battery that would mean (67/3) x 0.95 = 23.51A for the max amps per battery. So....if my batteries can supply a continuous current of 23.51A each I can run 200W on any resistance coil?

 

[mauricem00]

No problem, I take heed when corrected.

From the first link:

"A boost converter (step-up converter) is a DC-to-DC power converter with an output voltage greater than its input voltage. It is a class of switched-mode power supply (SMPS) containing at least two semiconductors (a diode and a transistor) and at least one energy storage element, a capacitor, inductor, or the two in combination. Filters made of capacitors (sometimes in combination with inductors) are normally added to the output of the converter to reduce output voltage ripple."

So with our chips is it just an inductor or is it both? Feel free to educate me.

our converters use an inductor to boost or buck voltage and a capacitor to smooth the output. this is common in switch mode power supplies. capacitive voltage multipliers are very inefficient and only used for low power or high voltage low current circuits. this is trivia that is not needed for safe vaping.but their are sites that teach how to design this kind of circuit on the internet that will give a lot more information than Wikipedia.the op really needs to learn a lot more about battery safety if they are considering cloud chasing.mods are so cheap that it's cheaper to replace or upgrade than to try to repair or modify them

 

[Susan~S]

Thanks Susan!, so if i read that post correctly, an rx200 at 200W would draw 67W of power from each battery. with a minimum voltage of 3V per battery that would mean (67/3) x 0.95 = 23.51A for the max amps per battery. So....if my batteries can supply a continuous current of 23.51A each I can run 200W on any resistance coil?

Yes. 200watts/9.0volts (3 cells at 3.0 min voltage)/0.95 = 23.39A per battery/cell.

 

[Susan~S]

our converters use an inductor to boost or buck voltage and a capacitor to smooth the output.

Thanks, that clears it up for me. I'll change my database and drop all references to capacitor.

 

[Baditude]

The processor in a regulated mod decides whether your battery(s) have enough amps (current) available to fire whatever coil you have on the mod. If the processor sees that there is not enough battery power available, it will display on the screen that there is not enough power. So no worries about over-taxing your batteries in a regulated mod. That's the beauty of regulated mods and protection circuitry.

Now, in a mechanical mod (no processor), its an entirely different story. You must do calculations yourself to make sure that your coil build will not pull more amps than the battery has to give, or very bad things can happen.

Explain it to the Dumb Noob: Ohm's Law Calculations

 

[mauricem00]

Thanks Susan!, so if i read that post correctly, an rx200 at 200W would draw 67W of power from each battery. with a minimum voltage of 3V per battery that would mean (67/3) x 0.95 = 23.51A for the max amps per battery. So....if my batteries can supply a continuous current of 23.51A each I can run 200W on any resistance coil?

in theory thats correct but very few batteries can handle over 20 amps and as they age the capacity goes down.many suppliers sell re wrapped batteries and exaggerate their ratings. to be safe you should limit that to 12-15 amps with new, high power batteries like Samsung 25Rs especially if you are running multiple batteries in parallel.just because the seller claims it will handle 30 amps does not make it true. a local vape shop sells 25Rs as 60 amp batteries but they can only handle 20 amps continuously and 100 amp pulses for less than 1 second according to the manufacturer. be careful and be safe.we do not want to see you on the evening news in another exploding mod story

 

[mauricem00]

The processor in a regulated mod decides whether your battery(s) have enough amps (current) available to fire whatever coil you have on the mod. If the processor sees that there is not enough battery power available, it will display on the screen that there is not enough power. So no worries about over-taxing your batteries in a regulated mod.

Now, in a mechanical mod (no processor), its an entirely different story. You must do calculations to make sure that your coil build will not pull more amps than the battery has to give, or very bad things can happen.

the processor only test for battery voltage not battery temperature or internal resistance. it will not fire at resistance that too low for the controller but does not protect the battery. even with a regulated mod you need to use good batteries from a reputable source and monitor your battery temperature

 

[Baditude]

the processor only test for battery voltage not battery temperature or internal resistance. it will not fire at resistance that too low for the controller but does not protect the battery. even with a regulated mod you need to use good batteries from a reputable source and monitor your battery temperature

I totally agree.

Processors have amp limits to protect the circuit board.

 

[Daz123]

haha don't worry I don't plan on building anytime soon, I want to fully understand every single detail before considering these super sub ohm builds. I still don't understand Ohm's Law though. Looking at the online calculator, say I successfully build a coil at 0.2 ohms and I set my mod to 90W. Now that results in a current of 21.2A. That would be total current required yes? so divide that value by 3 to calculate the current draw from each battery?

In regards to the processor not testing battery temperature, does that mean that going over the maximum discharge of your regulated mod would still cause battery vent and a possibility of an explosion?