Man, I've never been so confused. I have never seen a controller change battery count as much as the Jeti/Hacker Master Car controllers. I have the Master Car race and it has Jeti and hacker on one side of the sticker and the other it says it only handles 5-8 cells (NiXX) and the Ron= 2 x 0,0012 Ohm. It looks the same as the ones in Jeti's website
http://www.jetimodel.cz/eng/adv_car_en.html. Now I did a search and found that the Master Car sport handles 5-10 cells and has a Ron= 2 x 0,0012 Ohm and I found another one that syas up to 12 cells.