Wi-Fi doesn't really draw too much power. I got 1-2 days of battery life from my 8320 with Wi-Fi on nearly all the time and BeejiveIM on nearly all the time. Now if you do things such as stream radio with Pandora or Slacker, you will kill the battery. I had to use my 8700's battery as a spare battery for my 8320 because I killed the battery with Pandora.