I've got the Sony iPhone Alarm Clock and it charges my iPhone fully so no complaints here.
However, before I got my iPhone 4 I was still using the iPhone 2G and for some reason it stopped charging in the dock a year or so ago, but would charge everywhere else. But my wife's iPhone 3G would still charge in the dock so who knows.
hmmm same thing last night... I put it on, made sure it's squarely on and secure... at 80% the fully charged symbol comes up... however it is not 100% charged...
I can't remember the model on mine, but it charges no problem, screen on or off, phone on or off, every night as asked. Heck, it's even kind enough to pick Rammstein to wake me up this morning 🙂
if my phone is docked and turned off it will charge to a random % and stop charging (when phone is turned on while docked the battery indicator shows that it is plugged in but not charging).
if my phone is docked and turned on it will charge 100% ....