I was trying to measure the real talktime on my V400 and I noticed the connection drops at exactly 4:00:00 hours and the battery was still showing full charge. I guess they have some kind of feature to disconnect you at 4 hours. I guess I would have to reconnect again to find out how long it takes to drain the battery. But the problem is I am sleeping and don't know when the phone disconnects. What's the longest anyone has been continuously connected without dropping the connection?