Ohms law can be confusing or even intimidating for those of us who are less than comfortable with maths. The good news is there are only three equations that are pertinent to vaping either mechanical or regulated devices.
It is vital to how many amps your device and setup is drawing from your battery, and to choose a battery or batteries capable of safely delivering this.
All these checks can be modelled using Steam Engine main page, but it's wise to understand the maths that drive it, for instance in the unlikely event that you had no internet access.
On a regulated device
The resistance of the coil is irrelevant. Regulated mods separate the input and output voltage, in other words they separate the battery from the atomizer. The only relevant values are the wattage, and the remaining voltage in the battery.
As the battery voltage falls, the mod will increase the amp draw to maintain the selected wattage. You need to know the amp draw at full charge, and when the battery is discharged as this value will be the highest. Most regulated mods are about 90% efficient, so you will also need to factor this loss into your calculations as it will marginally increase the amount of amperage pulled from the battery.
To find the amp draw use I=P/V (-10%)
Eg.
60w divided by 4.2v equals 14.3 divided by 0.9 = 15.9 amps
60w divided by 3.4v equals 17.6 divided by 0.9 = 19.6 amps
With multi battery devices, simply calculate the amp draw then divide by the number of batteries.
An 18650 is fully charged at 4.2 volts, and can be considered discharged at around 3.4 volts.
The voltage that your mod cuts off at will vary depending on make and model. The Smok Alien for instance has a very low cut-off of 2.8 volts, whereas the Noisy Cricket 2 cuts off at 3.5 volts.
The best way to ascertain this for your particular device is to run the mod until it cuts off, then put the batteries on a charger. Make note of what voltage they are at, adjust your calculations accordingly, and potentially your wattage level and battery choice.
In a regulated mod it does not matter if the batteries are in series or in parallel, the calculations for amp draw per battery are the same.
On a mechanical device
The resistance of the coil controls the amount of amperage drawn from the battery, and therefore the wattage delivered to it. Calculate the maximum amps used, based on a fully charged battery at 4.2 volts. As the charge decreases, so will the amount of power and amperage used.
I = amps V = volts R = resistance P = watts
To find the amp draw use I=V/R
Eg. divide 4.2v by 0.5Ω = 8.4 amps
To find the wattage use P=V²/R
Eg. 4.2v multiplied by 4.2v divided by 0.5Ω = 35 watts
It is vital to how many amps your device and setup is drawing from your battery, and to choose a battery or batteries capable of safely delivering this.
All these checks can be modelled using Steam Engine main page, but it's wise to understand the maths that drive it, for instance in the unlikely event that you had no internet access.
On a regulated device
The resistance of the coil is irrelevant. Regulated mods separate the input and output voltage, in other words they separate the battery from the atomizer. The only relevant values are the wattage, and the remaining voltage in the battery.
As the battery voltage falls, the mod will increase the amp draw to maintain the selected wattage. You need to know the amp draw at full charge, and when the battery is discharged as this value will be the highest. Most regulated mods are about 90% efficient, so you will also need to factor this loss into your calculations as it will marginally increase the amount of amperage pulled from the battery.
To find the amp draw use I=P/V (-10%)
Eg.
60w divided by 4.2v equals 14.3 divided by 0.9 = 15.9 amps
60w divided by 3.4v equals 17.6 divided by 0.9 = 19.6 amps
With multi battery devices, simply calculate the amp draw then divide by the number of batteries.
An 18650 is fully charged at 4.2 volts, and can be considered discharged at around 3.4 volts.
The voltage that your mod cuts off at will vary depending on make and model. The Smok Alien for instance has a very low cut-off of 2.8 volts, whereas the Noisy Cricket 2 cuts off at 3.5 volts.
The best way to ascertain this for your particular device is to run the mod until it cuts off, then put the batteries on a charger. Make note of what voltage they are at, adjust your calculations accordingly, and potentially your wattage level and battery choice.
In a regulated mod it does not matter if the batteries are in series or in parallel, the calculations for amp draw per battery are the same.
On a mechanical device
The resistance of the coil controls the amount of amperage drawn from the battery, and therefore the wattage delivered to it. Calculate the maximum amps used, based on a fully charged battery at 4.2 volts. As the charge decreases, so will the amount of power and amperage used.
I = amps V = volts R = resistance P = watts
To find the amp draw use I=V/R
Eg. divide 4.2v by 0.5Ω = 8.4 amps
To find the wattage use P=V²/R
Eg. 4.2v multiplied by 4.2v divided by 0.5Ω = 35 watts
