Help Multiple charging issues

[Leishycat]

My Galaxy S2 has been having a couple problems recently, and I was hoping someone could help. These have mostly started within the past week.

First, the battery will sometimes say that it is fully charged, but when I unplug the charger cable, it'll be far from fully charged; sometimes as low as 40 or 50%.

Second, the battery will discharge fully while it is on the charger. The phone acknowledges that it is charging, but the battery percentage will slowly drop until it is at zero.

Third, sometimes when charging the charge light and battery indicator will rapidly flash between charging and not plugged in (so, the red light will flash off and on, and the battery indicator will flash between the charging icon and the normal use icon).

I have replaced the battery with a new one, and the problem persists. I have tried the phone on five different chargers, and the issue occurs on all of them.

Please help!

 

[Rukbat]

First, the battery will sometimes say that it is fully charged, but when I unplug the charger cable, it'll be far from fully charged; sometimes as low as 40 or 50%.

The battery has to be conditioned. Charge it to 100%. Leave it on the charger one additional hour. Now use it normally without charging it until the phone tells you to charge it, Do this 3 times.

Second, the battery will discharge fully while it is on the charger. The phone acknowledges that it is charging, but the battery percentage will slowly drop until it is at zero.

It's a charger, not an external power supply for the phone. Charge it with the phone off. The charger can't supply enough current to run the phone, so if the phone is on, the net effect is to discharge the phone slower.

Third, sometimes when charging the charge light and battery indicator will rapidly flash between charging and not plugged in (so, the red light will flash off and on, and the battery indicator will flash between the charging icon and the normal use icon).

Sounds like the charging port is intermittently connected. It has to be resoldered.

 

[Leishycat]

The battery has to be conditioned. Charge it to 100%. Leave it on the charger one additional hour. Now use it normally without charging it until the phone tells you to charge it, Do this 3 times.

It was doing that on the old battery as well. Could it be related to the below issues?

It's a charger, not an external power supply for the phone. Charge it with the phone off. The charger can't supply enough current to run the phone, so if the phone is on, the net effect is to discharge the phone slower.

Why would it start doing this suddenly though? It never had this issue until the past week, and I've had the phone for over a year.

Sounds like the charging port is intermittently connected. It has to be resoldered.

That's a possibility. Also, plugs are kind of loose in the port. So it might be a bad port, or a combination of the above.