I've had the battery disconnected between 30-60 minutes about a year ago. I know the headunit will lose the radio presets. I don't recall having to resend my contacts over bluetooth for the phonebook, though I've made edits and I can't be 100% certain. IIRC, it lost the pairing of my phone and I had to do that over. After you paired the two and if the 4Runner still says "phone not connected" after you turn the key, make a call from your phone. It'll connect right up and everytime the key is turned. I probably deleted and re-paired the bluetooth five to ten times thinking something was wrong.
I checked the nav address book, it doesn't appear any of that info is lost, such as memory points. Because I have a friend's address in the nav prior to disconnecting the battery, which shows the road, but there wasn't a name for the street. (He lives in a new development, which at the time he told me his address doesn't even exists in Google Maps.)
What will be lost for certain when the battery is removed, are both tripometers, radio presets, and auto or one touch open and close for the moonroof, driver's and rear window. To normalize them them again and regain the auto or one touch open and close, fully open the moonroof and window by holding the button down, keep it held down for a few seconds after it's been fully opened. The fully close the moonroof and window and hold the button in that position for a few seconds. The auto or one touch open and close function should be restored. IIRC, the rear wiper and defogger doesn't work until the rear window has been normalized.
