Recently I came across this weird problem on my iPhone that while charging the battery with the same wire and charger that I used to, it showed the fully charged icon on top right corner when it was still empty and charging.
It was a strange issue as I have been using my iPhone for over 3 years now and charging it the same way but I faced this issue for the first time and in the first couple of minutes it showed the same. At the first instance I thought it to be a temporary problem but I was surprised to see the same the next day too.
Possible workaround for this problem that a common guy can think of are as follows (this is what I did too):
1. Trying to charge it at some other electric socket or at some other place.
2. Leaving it uncharged/as it is for couple of hours (this is to keep it cool, in case it has been used for long)
3. Tried switching it Off and On (restarted the iPhone) to kill the processes running in background and boot it as normal.
4. Tried changing the USB cable to find if there is some issue with the wire.
But to my shock, nothing of the above solutions worked and I continued to face the similar issue of getting the full charge icon on top right corner even when the phone was not full charged.
So what I did was to try and charge the phone using the same charging cable but this time not with the charger, but with the laptop/computer USB. I was relieved to see that it started charging again instead of showing the full charge icon within 2-3 minutes as it used to.
This makes me believe that it is time to get my electric charger replaced. So what is the solution that worked for you?