What is the battery life? Are there batteries?

The Laser Egg contains a rechargeable, 2200mAh Lithium that can be charged with the USB charging cable provided in the box. It has a battery life of up to 8 hours. To prolong the battery life, you may turn the ‘LCD off’ on your Laser Egg by pressing the Mode button until you reach that screen. For continuous monitoring, we recommend that you keep your Laser Egg plugged in and charged with the micro-USB charging cord. Normal indoor use will also help maintain battery health.