ok ill try again
i am not the best one at explaining this
regulated vw mods do not care about the ohms of your coil period they draw the same amps from the battery regardless of the coil
what determines the amp draw on the battery in a regulated vw mod is 2 things basically the wattage setting and the voltage of the batteries
WHY??? im sure theres a lot of technical electronical reasons, I do not know but i have read enough everywhere to know this is how it works. theres a huge thread somewhere on here about thsi very topic that explains in great detail how this works, im giving you the very very very short version
so basically the higher the watts and the lower the volts the more amps are drawn from the battery
25rs are good at 20amps but you can go slightly higher like 25 for short pulses. in fact you can pulse it higher, but the concern comes form how much time between pulses you give the battery to cool down on weather or not it is safe. the concern gets worse if something goes wrong with the mod and it autofires. if it does this on a setting that is higher then the recommend amp rating of the battery, they could and probably will vent
but many will argue if you know what your doing you can easily draw more amps form a battery then is recommended for vaping purposes. i am not going to argue with that
i am simply addressing how to determine the amp draw of your battery on a regulated vw mod.
so as i said its all about the wattage setting and volts in you battery
so you mod can go up to 157 watts
your batteries at full charge are 4.2volts each and you add that together since the mod is wired in series. so you start at 8.4v at full charge
most mods will say the battery is drained at 3v per cell some are a little higher at 3.2v so once again add together for 6-6.4v
so your batteries operate in a range of 6v to 8.4 volts
now there is a 3rd factor called efficiency which take si nto acct the wiring and so forth in the mod which causes voltage sag meaning that USUALLY the full voltage of the battery does not reach the coil. so even though your batteries are at full charge 8.4v they are operating slightly lower
most mods have an effeiciency of about 90%. some are better some slightly worse.
so the formula is
wattage setting of the mod divided by current voltage of the batteries divided by mod efficiency
so at 157 watts and full charge
157/8.4/90%= 20.767 amps
now at low battery cut off of 6v
157/6/90%=29.074 amps
now at 3/4 discharge approx. 6.6v
157/6.6/90%=26.43 amps
im not going to tell you if pulling 29+amps from a set of 25rs is bad. it can be done safely. but it can also cause them to vent. the mod is not necesssarily going to stop the batteries from venting. it can not read the internal temp of the battery to know the battery is about to vent. but with the 10 second cutoff most mods have that is often enough to stop you from holding that fire button in too long to cause the batteries to vent usually the issue occurs when things go wrong. board misfuctions, you have the mod turned on in your pocket and the button keeps getting hit and released over and over, etc.
you decide for yourself what you consider to be safe. maybe go do a google search for mooch and read some of his stuff and watch some you tube videos where he is interviewed to understand what is and aint safe
use the formula i gave you to figure out amp draw and you will know what your amp draw is for your mod and make your own decision
me i never vape much above 50 watts so i care less about this stuff any more. at 50 watts i never draw above 10 amps from a battery and all my batteries are rated at at least 20amps. the concern is pushing 2 battery mods above 120ish watts is where you start getting into the debate of how safe it is
given the fact there are so many that do this now you can think there is some safety features or magic going on in side your mod to stop it from being unsafe. the truth is there' s not. the truth is the manufacturer's are recommending you use 20amp+ batteries, hoping you do so,, because they know 20amp batteries under most normal vaping circumstances should (keyword should) be fine pulsing at 25-35 amps. but the mod doesn't know what batteries you are using. put some 10 amp batteries in your mod and set it 157 watts and chain vape it till its at low battery cutoff. they will most likely vent at some point before you hit low battery cutoff because they simply can not take being pulsed at double to triple their recommend pulse rating continuously while you chain vape. The mod wont stop them from venting. it has no way of detecting their temp or when they are venting. that's not to say one could not use the full discharge of good 10 map batteries at 157 watts and do it in such a way that the batteries do not vent. but most people are not paying enough attention to the battery temp to know how hot they are at any given time.
my personal opinion is your good using you mod at 157 watts with your batteries. but if you chain vape it, open the battery door and feel the batteries with you hand, if they are very hot stop using them till they cool down. and if you like to vape above 120watts be mindful you are pulling more amps from the batteries then the manufacturer recommends once the batteries discharge past about 6.6v and if something goes wrong with the mod and causes the batteries to vent...its your own fault.