Stack 'em and put it in AVG - I believe you can go up over 20 watts. The display won't tell you that with AVG though.
Where do people come up with this cr....
15w MAX and AVG mode is the most uncontrolled and worst setting to use.
The reason it seemed to do more than the EGO Twist at 3.2 is because even set to 3.2 it was outputting closer to 4+v.
Proper/Best and simplest setting to use is Set for Watts and Set to RMS - this gives the same power no matter which head you attach and is the best regulated for consistency.