Many thanks. As the receiver and the servos are stock, I can't find any information for their operation. For the servos I know that are 9,2kg, 0,13sec. Metal geared. The manual doesn't refer to their specification. I don't even know if servos are analogue or digital. So I assume that servos and receiver works at 6volts. So the 4 AA batteries in the receiver box must be connected in series. It must be. The buggy is the kyosho scorpion bxxl nitro version 2wd. 5,5 Kgs, with .32 engine. I haven't done the break in of the engine yet. So based on the assumption of 6volts operating voltage, I prefer to use some other kind of power source than the 4AA pack. What its better Nimh or Lipo?