Question about dual 18650 regulated mods

[Psofos]

Hi there,i've been confused about amperage draw in regulated mods with 2 18650 in series.
My question is if the mod draws let's say 4.5 volts on a 0.2 ohm coil that means it drains 22.5 A from the battery.
When i have two 18650 in series do both of them drain 22.5 A?
Or 11.25 A each?
Also does it draw 4.5 volts from each or 2.25?
How do people get away with super low ohm builds on super high watts on regulated box mods?

 

[KenD]

Do you have a vv or a vw mod? With be mods resistance doesn't factor into the amp draw, only wattage and battery voltage. For example:

60w / 3v = 20 amps (and a bit more due to circuitry drain).

However, in a series mod you have the voltage of two batteries available so you're at half the amp draw:

60w / (3+3v) = 10 amps (per battery)

In a vv mod watts are of course calculated by resistance and volts (4.5 x 4.5 / 0.2 = 101.25w), but the amp draw is based on the actual battery voltage, not the set voltage. So, in your example, with a single fully charged battery you're drawing about 24 amps

101w / 4.2v = 24 amps (25-26 amps with circuitry drain)

With a depleted battery:

101w / 3v = 33.75 amps (36-37 with circuitry draw).

Again, with a two-battery series mod the battery voltage is doubled, so:

101w / 8.4v = 12 amps
101w / 6v = 17 amps

Sent from my M7_PLUS using Tapatalk

 

[Psofos]

I have an istick 50w for now and thinking of getting a kbox 200 for my aromamizer.
So what you say is that i should ignore the voltage reading on the mod and calculate with the voltage on the battery? 4.2 charged and so on? I thought amps were V/Ω.

 

[edyle]

I have an istick 50w for now and thinking of getting a kbox 200 for my aromamizer.
So what you say is that i should ignore the voltage reading on the mod and calculate with the voltage on the battery? 4.2 charged and so on? I thought amps were V/Ω.

If you want to find the
amperage draw from the battery
you need to use the
voltage of the battery
and the wattage output of the battery.


the confusion comes from using the 4.5 volts which is the voltage output of the regulation chip.

 

[Psofos]

If you want to find the
amperage draw from the battery
you need to use the
voltage of the battery
and the wattage output of the battery.


the confusion comes from using the 4.5 volts which is the voltage output of the regulation chip.

Got it,so i calculate with 8.4 volts fully charged and below if in series. Thanks a lot both of you.

 

[KenD]

I have an istick 50w for now and thinking of getting a kbox 200 for my aromamizer.
So what you say is that i should ignore the voltage reading on the mod and calculate with the voltage on the battery? 4.2 charged and so on? I thought amps were V/Ω.

Amps are volts x volts / ohms for unregulated mods. With regulated mods that's what the atty "sees", but it's not the battery drain. Batteries have the voltage they have, they can't give out more than their current charge level. The circuitry of the mod "exchanges" amps for volts to provide the voltage/wattage requested. That's why the amp draw goes up as the battery voltage goes down, the batteries are worked harder to provide the power needed. Calculate with the wattage you're at and the cutoff voltage of the battery (3.2 for a single battery and 6.4 for a dual series should be good, but use 3 or 6 if you want to be extra safe.

The istick has a built in battery, right? In that case I think it's safe to assume that you can use it at its full wattage without problems (but somebody who knows better, please chime in). As for the Kbox 200, no two-battery mod can safely do 200w. If it's a good design it pulses above 150w. For that range you want 30 amp batteries (there are no.18650s with cdr higher than that), which would be the Sony vtc4 or the LG hb6. 20 amp batteries are good up to 120w or so. If you want to have true 200w you need a three-battery mod (for example the Reuleaux rx200) or a mod with a built in lipo battery (for example a dna 200 mod).

Sent from my M7_PLUS using Tapatalk

 

[Psofos]

Makes perfect sense now. Yeah i know it can't do 200. Will wait for a nice review first.
I don't think i'll hit over 120 watts but i wanted to understand so i play safe.
Thanks again.