Using (2) 2S LiPo pack is putting out 14.8 volts. Using (2) 3S LiPo packs is putting out 22.2 volts. I couldn't imagine running that monster buggy with 6 cells. The general consensus that I read about powering the XL---sweet spot is using two 2S packs. The power increase from using two 3S packs makes the Yeti XL quite a handful to control.