I saw the warning in the manual and dismissed it as just health and safety nonsense, but when the battery got low on my new S4 and the phone battery warning / charge request told me not to use it whilst charging I was fairly surprised and very irritated. To my mind, the fact that the phone requesting you not to using whilst charging, and the manual warning you not to use it whilst charging makes this one of the least usable electronic devices I've ever had! Yes it is supposed to be a portable device, but as a device that will probably have to be charged once a day, to be unable to use it half of the time when it has to be plugged in massively devalues it. So Samsung are saying that I can't listen to music before sleeping? I can't use it with a car charger? I can't plug it in to save battery? I've never had an electronic device or phone that tells me not to use it whilst plugged in, and I've never had a phone that has been unable to charge whilst I've been using it. So why is the S4 so different? Have I misunderstood? I suspect I have as I haven't seen any other discussion on this. Should I just ignore it, or is this a real issue?