I have an iPhone 4. I just noticed it today when I was using an alarm app. When I went to sleep my phone was charging and it was on 78%. When I woke up it was on 4% and it showed it was still charging. Later that day I let it charge to like 50% then started played some games. When it reached 20% and the noticed popped up, I plugged it in and it started charging.About 5 minutes later, The notice popped up again saying I had 10% left. I really have no idea what's going on. I don't have the original chargers that came with the phone. I lost em… Ehehehe. I have a black apple cord and a glow in the dark wall plug.
I also got the phone about 2-3 Weeks ago.
Does anyone might know what's going on?