Ok I have a variable voltage tesla can go to 120watts. I have a kangertech mini that says it can go between 15 and 60 watts. But at 50 watts it tastes burnt. Is it because I shouldn't go that high or do I need a new coil? I've only had this coil for 2weeks and a tank of juice on it lasts me maybe 2weeks as I don't do it alot. Suggestions?