I'm connected to 4G but barely. Using the signal strength bars running ICS i have 2 bars. Looking at the signal strength found in settings, it says 4G-115dBm. I have found that the charger simply keeps the battery at a constant level without much advancement. i.e. not much happening besides staying put while i use the phone. So if i start using the phone with 50% power it simply stays there even plugged in for an hour. This all occurs under constant use of the phone. If i don't use it it will charge correctly even with a fairly poor signal. In a strong signal area it charges normally. I also note that in 3G with a stronger signal in the same location as the poor 4G signal it charges correctly. Is this normal? I can only gather the phone is fighting to maintain a 4G connection at the expense of charging correctly.