Help Question about battery charge

[HitTheLights]

Hi.

I have a question about charging the battery of my Samsung Galaxy S2.

Yesterday my phone ran out of battery life so I charged it while it was on. It charged until it reached the 100% status.

Then I turned off the phone (without removing the battery charger) and i noticed that the phone was still charging while it was off... after about 10 minutes it stopped and the battery status showed 100%.

Now how can it be that the battery status is 100% while the phone is turned on and when I turn it off it keeps loading for about 10-15 minutes?

Ps. The battery charger was never removed while i was experiencing this.

I would be thankful if someone could help me

 

[Tinderbox (UK)]

Maybe when you turned the phone off, the charging circuit was switched off as the phone shut down, during this it would be using the battery and maybe the battery charge level dropped to 99%, and once it was off it realized the charger was plugged in started charging again.

I have notice with my S2 , that when charging with the phone on, even though the charge has hit 100% it will continue to charge for another 20 mins.

I found out that the full voltage of an lin-ion battery is 4.20volts and the charging stops at this level , but my S2 shows 100% charge before the voltage hits 4.20volts, that`s why my S2 continues to charge for 20 min`s more.

 

[HitTheLights]

Maybe when you turned the phone off, the charging circuit was switched off as the phone shut down, during this it would be using the battery and maybe the battery charge level dropped to 99%, and once it was off it realized the charger was plugged in started charging again.

I have notice with my S2 , that when charging with the phone on, even though the charge has hit 100% it will continue to charge for another 20 mins.

I found out that the full voltage of an lin-ion battery is 4.20volts and the charging stops at this level , but my S2 shows 100% charge before the voltage hits 4.20volts, that`s why my S2 continues to charge for 20 min`s more.

Hm I think that it would be quite a long time for charging 1%
I read somwhere that the Android System stops the charging for example at 94% (but it displays 100%) to save battery lifetime. I also read that if you charge the battery while the phone is off, it would charge the real 100%, but it would also diminish the lifetime of the battery.

Does someone here know if this statement is true?