As a follow up article to http://www.ecigssa.co.za/shauns-guide-to-battery-safety.t17245/ I have decided to go into a bit more detail in regards to battery drain.
a common question I get asked is "I have this coil on that battery and I’m firing at these watts, am I safe?" then I go out, get the calculator, plug in all of the values and return with an answer.
So how do I do it ?
start by going to the Battery drain page on Steam-engine.org
http://www.steam-engine.org/batt.asp
select the mod type : regulated or unregulated
enter in your atomizer resistance
select your battery from the presents (if it’s not there then you would need to manually enter in your battery specifications)
then compare your current value in the battery drain section to the amp limit. the amp limit headroom will tell you how much headroom you have before stressing out your batteries (the preferred amount is 20%)
if your amp limit headroom value is in the negative then your battery drain is higher than how much your battery can take!
all done
Important side note !
steam-engine does not take into account multiple battery configurations. what this means is that if you have a mod with more than 1 battery you will need to manipulate the calculations manually.
if you have a parallel mod >
a parallel mod will double your amperage and mah. the voltage will stay the same
if you have a series mod >
a series mod will double your voltage. the amperage and mah will stay the same.
what does this have to do with my battery drain?
if you had a 0.5ohm coil and your pushing 50w on a single 20A battery (Samsung 25R) >
you would be using 11.9A with your battery limit being 20A
the same build on a dual 18650 parallel mod >
you would be using 11.9A of current with a battery limit of 40A
the same build on a dual 18650 series mod (double the battery voltage value) >
you would be using 5.95A of current with a battery limit of 20A
*since the amp draw is less the battery life will be much better than a single 18650 even though the mah is the same
How exactly does it work ?
There are two main types of mods: Regulated, and unregulated (mechanical). As far as battery drain is concerned, these are two completely different animals.
In an unregulated mod, a lower resistance atomizer means more current drawn from the battery, and less battery life. In a regulated mod, things get more complicated, and the rules are different.
Unregulated mods – a battery with a coil on it
Unregulated (mech) mods are very simple devices. They have one circuit. This circuit can be easily modelled using Ohm's law. In other words, if you have a basic understanding of Ohm's law, that is all it takes.
The battery drain is determined by two factors:
Regulated mods – fixed or variable voltage or power
Regulated mods are more difficult to model. But even though they are much more complex than mechs, with some selective simplification we can safely ignore most of the complexity. So we break these mods down into two circuits and a black box. This makes our regulated mod model little more than twice as complex as our mech mod model.
The two main circuits of a regulated mod are:
source : Steam-Engine.org
http://www.steam-engine.org/batt.asp
a common question I get asked is "I have this coil on that battery and I’m firing at these watts, am I safe?" then I go out, get the calculator, plug in all of the values and return with an answer.
So how do I do it ?
start by going to the Battery drain page on Steam-engine.org
http://www.steam-engine.org/batt.asp
select the mod type : regulated or unregulated
enter in your atomizer resistance
select your battery from the presents (if it’s not there then you would need to manually enter in your battery specifications)
then compare your current value in the battery drain section to the amp limit. the amp limit headroom will tell you how much headroom you have before stressing out your batteries (the preferred amount is 20%)
if your amp limit headroom value is in the negative then your battery drain is higher than how much your battery can take!
all done
Important side note !
steam-engine does not take into account multiple battery configurations. what this means is that if you have a mod with more than 1 battery you will need to manipulate the calculations manually.
if you have a parallel mod >
a parallel mod will double your amperage and mah. the voltage will stay the same
if you have a series mod >
a series mod will double your voltage. the amperage and mah will stay the same.
what does this have to do with my battery drain?
if you had a 0.5ohm coil and your pushing 50w on a single 20A battery (Samsung 25R) >
you would be using 11.9A with your battery limit being 20A
the same build on a dual 18650 parallel mod >
you would be using 11.9A of current with a battery limit of 40A
the same build on a dual 18650 series mod (double the battery voltage value) >
you would be using 5.95A of current with a battery limit of 20A
*since the amp draw is less the battery life will be much better than a single 18650 even though the mah is the same
How exactly does it work ?
There are two main types of mods: Regulated, and unregulated (mechanical). As far as battery drain is concerned, these are two completely different animals.
In an unregulated mod, a lower resistance atomizer means more current drawn from the battery, and less battery life. In a regulated mod, things get more complicated, and the rules are different.
Unregulated mods – a battery with a coil on it
Unregulated (mech) mods are very simple devices. They have one circuit. This circuit can be easily modelled using Ohm's law. In other words, if you have a basic understanding of Ohm's law, that is all it takes.
The battery drain is determined by two factors:
- The resistance of the atomizer, which is more or less constant after you have built your coil(s).
- The voltage of the battery, which decreases as the battery drains.
- The voltage hitting the atomizer is the voltage from the battery (minus the tiny voltage drop in the switch and conductors).
- The current flowing through the battery is the current flowing through the atomizer.
Regulated mods – fixed or variable voltage or power
Regulated mods are more difficult to model. But even though they are much more complex than mechs, with some selective simplification we can safely ignore most of the complexity. So we break these mods down into two circuits and a black box. This makes our regulated mod model little more than twice as complex as our mech mod model.
The two main circuits of a regulated mod are:
- The atomizer (output) side.
- The battery (input) side.
source : Steam-Engine.org
http://www.steam-engine.org/batt.asp
