12 Volt Battery Substitute

[maniac_2040]

Hey, I'm the programmer on my team and I'm using a Vex bot to test code on while the main robot is not complete, but I'm using the regular Robot Controller, which takes a 12 volt battery. As of right now, I am just using a 12 volt power supply, which is very inconvenient because the robot has a cord dragging behind it when I try to drive it and a regular 12 volt battery is much too big/heavy to put on this miniature bot. So my question is are there smaller and lighter 12 volt batteries I can use? Or, is it possible to use a 7.2-9 volt backup battery as the main power source? seeing as how I only have a few vex motors(which are powered via the backup battery anyways), a gyro, and possibly a CMUCam (also powered via backup battery) on the bot.

Thanks in advance.