Well, if you run batteries in series you also double the voltage wich in turn would quadruple the rpm (no load) so i dont think the controller nor the motor and certainly not the plugs and wiring is up to the task unfortunately..

So today i lost my patience a bit and pulled out the heat sink with the ESC just to see if i could find the controller specs. I have to break some warranty seals in order to get to the PCB so im not ready to do that yet. But there was a sticker with a barcode on it wich had this info: 

Working voltage: 60

Max amp: 40 (limited)

So i guess the controller might be good for more. Until someone has the guts to Connect it to the lingbo software we just have to wait... Exiting times ?