Hello Folks, First off I want to introduce myself as I am new to the forum and for a good reason. I started vaping in about June of 2017 as I was starting my journey on quiting chewing Tobacco. I have been very successful and love vaping as an alternative. My first mod was a Smok GX2/4. I know its a big boy for a beginner but for some reason I have natural iron lungs and can take the clouds it produces without choking. I eventually got a TFV12 tank for it and I LOVE IT. Most of the coils are sub-Ohm and my current coil is a 0.12 ohm coil head. Which leads me to today.... So me and my buddy both decided to try our hands at RDA's. We both ordered Ijoy RDA's his being the Combo and mine being the CIGPET Eco 12 RDA. I would consider myself an intermediate vaper at this point as I am always researching, watching youtube videos, and keeping up to date on my batteries, mods, etc. Him I would definitely consider a beginner. He has only used low wattage devices such as JUUL's and Suorin's. He now has a Smok ProColor with a TFV12 and he loves it. So we both want to try RDA's now. He wants me to do his build as he does not fully grip the topics of Ohm's law, Wattage, Amps, and Voltage. So basically he does not know or trust himself to build his own build as of right now. So my plan is to teach him to build through this process and to do it SAFELY. So I have spent this week watching multiple videos about Ohm's law, researching Ohm's law and just trying to take in all the information. What I have come to is that regulated series mods have chips that slighly alter the amount of Amps and voltage that a mod is using depending on the wattage you hit it at. Also that Ohm's do not entirely matter when you are hitting on a regulated mod. That as long as you build a coil with low enough resistence that your mod can hit the wattage range for that coil. We decided to go with prebuilt coils for our first time and just get building safely down, and then go from their (Building own coils and such). So here are my questions... Is it safe to use samsung 25r green batteries in a dual coil .25 ohm mod Smok Alien mod? Also if I am using a dual coil build will the ohms divide in half from .25 ohms to .12? If so is this still safe? Ive been really in to battery safety lately as I just had to rewrap my batteries (cheap and some advise against it I know). I realize that we will need to change our mod settings to Nickel as they are NiChrome coils. I just want to get this safety down before we start building and one of us loses our face because we did not take enough precaution. Also I do my best not to give vaping a bad name because we cannot afford it with the FDA trying to shut down the community. I am open to any advice and tips to help me understand better. I did see a thread on here about how to calculate amps in a regulated series mod and I believe I understand but I just want to double check. My understanding is that Amps=Wattage/Volts. Which is what you use when you build on a regulated mod.