i use my phone all day and at bedtime charge it until the morning.
Am I doing any harm by leaving it plugged in while it's already 100% charged?
At bed time it's usually at 30-40%
Personally, I don't like leaving my phone or any other electronic on the charger if the battery is full or near full. It can shorten the life. Since everyone can't charge their phone up in the morning they have to charge it overnight. I on the otherhand usually wait until the morning to charge. Between the time I get up and actually leave the house I can charge 40-50 percent and then I'm at a computer all day at work. With the battery life of the iPhone 4, I haven't had to charge overnight once.
It should be fine, now im not sure if its true for iphone battery as some batteries where you can let it drain completely then recharge so that you can get a better life is that possible? I know it worked for my tilt2 battery and blackberry batteries that i've had.
