Should MacBook Pro owners always use the battery source as opposed to AC. Having the battery soldered in removes the option of operating in AC only mode which I prefer. However, I do understand that a battery is like a muscle and it's use it or lose it kind of thing. However having it connected using my HP allows for a brighter screen. Does using the laptop with a fully charged battery while connected to AC degrade the battery in any way, even though there is a auto cutoff for the battery charge. Can anyone give an idea of what the average user does.