The T2 requires 4x AA batteries to operate. With alkaline batteries, the T2 is estimated to provide 40 hours of operation. With rechargeable batteries, you can stretch battery life to approximately 25 hours.
Using headphones will help to conserve battery life. Additionally, the T2 does not have a backlight. While this may be a drawback, it’s in fact another feature that drains battery life. Without it, the T2 requires very little power to operate and is designed to run for many long hunts without battery replacement.