For the last couple of days, I've noticed a very troubling issue with my phone's battery. I have it plugged in, and its still losing charge. Yesterday, I plugged it in when the battery was around fifty percent. When I used my phone a few hours later, it had dropped to 47 percent, even though it was on the charger. Just a few minutes ago, I went to check the notifications and found that my phone was at 99 percent, also on the charger. Doe anybody know what could be causing this issue, and more importantly, how I can fix it? Please note that the nearest apple store is in a huge mall, and I have no way to get there.