Batter shows discharge when plugged in power outlet after full charge

[#1]

I plug my phone for charging in main power outlet, the led light shows up it is charging. After charging, if I leave it for say couple of hrs, it shows discharge sometimes as low as 93%.

My question, why can phone keep itself charged?

To top it off, I have to plug mini usb out and back in to restart charging. Any idea's.

FYI:My battery is lasting 2days after 100%.

[#2]

This actually seems to be pretty common. From what I've read on this so far, it seems that once the battery is charged to 100%, the charger will stop and the battery will then start to drain. Once it is drained down to ~90%, the charger kicks back in again and then the cycle continues until you unplug the charger. Not sure why the charger 'shuts off' but it probably has something to do with conserving battery life. Anyway, I hope this helps!

[#3]

I m seeing this 1st time, all my previous phone always left charger at 100%. Battery hogger's  should definitely do the same.