wattage mode is correct
your battery is capable of TC Mode (temp control) but your tank is not.
with a .15 coil I would start around 50 watts and bump up from there. watch your voltage. when you hit 3.7 - 4.2 you should be hitting the sweet spot for that coil. take note of what wattage it is and work it from there. higher wattages will tend to burn out the coil faster. lower wattages will be weak and not produce clouds.
Very important to have your air flow wide open. low air flow will also produce unsatisfactory clouds and tend to burn out coils.
hope that helps.