I don't know if it is related to the battery meter and calibration or not, but I have seen this a few times now.
If you have a battery that has not been used recently (I busted out everything I had for XMas Jam this year) and it does not seem to take a full charge, run the device until it powers down, then recharge the battery again. If it takes the full charge after that, you should be good.
Even an old Sony battery that came with my 722 and had not been used for a couple of years, did not take a full charge on the first cycle, ran like a champ after running it down and recharging.