II have a volcano inferno its my first tank i purchi got The 600 mah & the 900 mah battery and the 4 ml tank with the 1.5 ohm duel coil cartomizer...anyways... I'm vapin all day and the batteries are running dry quickly ...I wanted to get another battery as a backup.... an 1100 battery give me more timeo out of the battery...Im also looing at the Mega Riva 1300 battery.... for extended battery life....as it stands right now if im home all day Im vaping and i have to charge both the batteries during themday and rotate them...... also if i went up to a bigg er tank... i was looking at a smoketec ....are thier cartomizers easy to get anywhere ...the XL ones with the bigger tank........and one other thing i find with this volcano inferno i don't get a deep throat hit it kinda fluffy...airy .....are the batteries the way to go with the tank or are there other options to suggest... do I go with a variable volt batter and can you use those with tanks? many thanks to all your resonses so farits a big help