Hello! I just bought myself an Eleaf iStick 100W mod with 2x Samsung 3000 mAh 30Q 20A batteries and an Eleaf iJust 2 atomizer with the default 0.3ohm coil. I've been vaping for almost a week now liquids with 3-4 mg/ml nicotine but they're rough on my lungs as in the last 2 mornings I coughed everytime I vaped. Many times I have to vape at under 30W to avoid coughing, and at 25W my voltage is 0.25v. My question is, will my batteries have a short life (not in the terms of charghing - I vape around 8-9 ml/day and it lasts me for almost 2 days) at this kind of low voltage? I'm not even a novice in terms of electronics so I don't know if the possible voltage of the batteries (4.3V-3.6V) correlates with the voltage that I vape at.