Ultra-Performance: 70C - 200C. With the Ultra-Performance line from Swaytronic, there are no limits; they are exceeded. Technology and performance: In addition to the high-quality manufacturing process of the Best-Performance, the Ultra-Performance line features additional additives mixed into the cell chemistry for maximum power density. The internal resistances stabilize at an all-time low after just a few cycles, providing more power than you need. Application: The focus of Ultra-Performance is in the FPV drone sport, high-performance jet models, and 3D helicopter flying. However, selected other areas are also covered. Ultra-Performance cells are used wherever previously used cells were not powerful or stable enough or reached the critical temperature range.