I put my charger in my phone when it was at 13%, when I did this the screen suddenly turned black so I turned it on again and the screen went black again, I then turned it on again and it seemed to be fine as it said it was charging. I then checked it a couple of minutes later and it was at 10%? It still said it was charging so I decided to leave it. 9 hours later it said it was at 50% which seemed to be a very slow charging time. I then took the charger out and put it back in and it seemed to charge faster. On another occasion I was using it when it was very low in battery. The phone then suddenly turned off, I then turned it on again and straight away it turned off again. This happened four times until I left it for a bit, it then seemed to work. On another occasion the same thing happened but it wouldn't turn on again until I left it for a bit. Don't know what the problem is, my phone is only 4-5 months old and I've only charged it when it has been very low in battery.