Lynxmotion Tech Support

I connect 18 servo to ssc-32, remove jumper VL=LS1 supply VL with 9V 320 mA and supply 6V 2300 mA to VS1. When i send all=1500 command to SSC all servo move to it center position. At this point it seem to be OK.
but when I leave it at about 2-3 minute all servo start move to 180 degree by it self. (I don't send any new command to SSC the last command is all=1500).
Now all servo position is 180 degree so I send all=1500 again but this time all servo don't come back to 90 degree. then I reset ssc and re-connect LynxTerm and send all=1500, servo go to 90 degree and again if I leave it for 2-4 minute servo will start to move again.

what wrong with it?

Batterys are probably under charged. Use a multimeter to monitor voltage and see if it decreases to below normal operating voltage.

Not sure what you mean by servos going to 180... Can you post an image of your wiring and maybe a video? Does the LED blink when the servos move on their own?