Great coils, great tank, but...they require high wattage to be used efficiently and do drain batteries faster in the process. My mod is 100 Watts max (which I had previously assumed was plenty), and this tank maxes out it's power. When my battery get down to about 60%-70% it no longer has the power to push this coil and I need to recharge. With that being said I still give these coils a 5 star rating because they work wonderfully under optimal conditions and last longer than anything I've tried previously.