Meet the GeekBot V2: an awesome kit that lets you build a fully programmable rover robot. It comes with a battery, chassis, servos, and everything you need to get started. GeekBot has a payload capacity of 2.2lbs. The robot can avoid obstacles and has LED and buzzer outputs.
GeekBot comes with a 4400 mAh rechargeable battery. It is powered by the Arduino based Geekduino Microcontroller. The basic kit is available for $149.95.