Servo stalls(?) on Arduino IDE sketch "Sweep", what could be wrong?

Really? I tried researching the current draw of the S3003 and most places said 150-500 mA. What kind of battery power would you recommend if I wanted to use this servo on a obstacle avoidance robot (to sweep the sensor)? I'm going to start with my little TowerPro SG90 9g servo, but I got the Futaba as well in case the little one doesn't last long.