Charging when not plugged in

[ErnieB]

For the last 2 days at approx 1.30pm my phone has bleeped and said that it is charging even though it is not plugged in. Yesterday I switched it off and then back on and it was OK but today I had to remove the battery before the 'charging' icon disappeared. Also at about 5.45 this morning it started beeping and I had to switch it off before it stopped.

Any ideas?