found this - Voltage and Ohms - might be helpful

[clivealive1]

***********  NOTE:  This is purely for folks using factory built kit and the lowest resistance is around 1.5ohms. Even that can be too low for some ego type batteries. ***********


hi, I found this thought it might be useful to some:

Ecigarettes - Voltage and Ohms

Long story short, if you have an ecigarette with high voltage and low ohms, your ecigarette will produce a larger amount of vapor and more throat hit as the heating element will reach a higher temperature causing more E-Liquid to vaporize per vape. Reverse the two to have low voltage with a higher ohmage and your e-cigarettes heating coil will heat up to a lower temperate resulting in less vapor and less throat hit but with reduced possibility of the infamous dry burnt hits many vapers have experienced (including us!)

High Ohms, Low voltage

This combination produces less vapor the further you go to the extremes of the two at the exchange for a longer battery life and much reduced chance of dry burnt hits. This combination also extends the life of the battery as there is less power being pulled from it reducing the chances of the battery giving up prematurely from the larger amounts of voltage being drawn.

Low Ohms, High Voltage

More vapor is produced due to the higher heat of the coil (basically more energy is being put through the thinner piece of coil resulting in a higher temperature). More power is used in e-cigarettes with a higher voltage and lower resistance clearomizer/atomizer so your battery will run out of charge faster. In addition, with the increased heat and vapor production there is a greater chance of a "burning taste" due to the higher temperature potentially causing E-Liquid to vaporize quicker than the wicks can draw liquid in, resulting in the burnt taste rather than a clean vape. The extra vapor produced uses more e-liquid and as a result you must refill more quickly.

Many people who enjoy the "throat hit" of vaping will build an e-cigarette of this style as with the greater amount of vapor produced the throat hit is larger. There is however a fine line between having an excellent low ohm high voltage e-cigarette and a one which constantly causes a burning taste. If you ever do get a burning taste, try using a slightly higher ohm tank or a lower voltage battery. Mix and match so to say!

I still don't get it

No problem, basically you want to find a combination of as low a resistance clearomizer/cartomizer as possible with a battery suitable (adjustable batteries are great as you can find the sweet spot for different cartomizers/clearomizers) so that you do not get dry, burnt tastes out of the e-cigarette. The reason you want to go for as low a resistance as possible is that the best flavor and vapor production lies here. Please bear in mind with e-cigarettes that everybody has personal preferences and as the old saying goes with vaping YOUR mileage WILL vary! Try out some different combinations and see what works - many people hate some clearomizer brands which are praised by others. It really does fall down to personal preference, good research and experimentation. This applies to all aspects of the e-cigarette: Batteries, clearomizer/cartomizer/tank/atomizer and E-Liquid. All of these play a large role in the resultant vape quality.
Happy Vaping!

[VapingBad]

It just says more power = more heat.

[Blownupdolly]

Thank you so much for that Clive. Normally when this subject come up my eyes glaze over and my brain wanders off somewhere else, as it's all too complicated for me. This is the first time I have read an explanation that is simple, clear and easy to read. Well done for finding it.

[tominmids]

A nice simple explanation Could be very useful for newbies

[robby]

Nice post Clive . This pic is a good analogy of watts, volts and amps, Hope someone finds it useful

[4madcats]

Sorry to be the party pooper but I would add a disclaimer to this to say this is purely for folks using factory built kit, were the lowest resistance is around 1.5ohms & even that can be too low for some ego type batteries.

The speed that folks move to rebuilding now is scary & anyone reading this who is building their own coils might be tempted to go beyond what is safe when going for the lowest resistance, so a wee reminder to find out what amps their battery is rated to, & then use an Ohms law calculator to stay within safe limits might be a good idea. 


Edit - crossed posts with kalbo, but yeh +1

[kalbo]

[/quote]

Low Ohms, High Voltage

More vapor is produced due to the higher heat of the coil (basically more energy is being put through the thinner piece of coil resulting in a higher temperature). The reason you want to go for as low a resistance as possible is that the best flavor and vapor production lies here.
[/quote]

While your absolutely right here, there are some serious safety issues attached using low resistance coils.
As most people seem to be a bit baffled by ohms law, here is a simplified example of how to understand how to make low ohms vaping safer(no vaping is fool proof safe)

Firstly you need to understand your battery limitations, I'm currently using AW IMR 18650 2000mAh which have a 10amp max output. Fully charged it's 4.2volts

So here's the deal, I build a dual or quad coil with a resistance of 0.3ohms is it ok? No!
Volts/Resistance: divide your battery voltage 4.2v by your coil resistance 0.3ohms
4.2 / 0.3 =14amp
This would be dangerous to say the least, drawing 14amp from a 10amp battery would be asking for trouble and could cause a thermal meltdown or explosion.
In short, if your set up is going to drain amps in excess of you battery output capability, your resistance is clearly too low, simple! To reduce the risk when vaping with low resistance coils you really must be sure you know what your doing.
This isn't a guide, as it's much more complicated than I can possibly explain here, but at the very least if your going to vape at low ohms you should know how to ensure your battery is upto the job and be aware of it's limitations.