Charging phone lion battery

Hello,

I have an Xperia S phone, with the microusb and charging unit (the one that sends current to phone and charge battery) from the mainboard are not working.

So, I must charge the battery when is inserted to the phone, so I can use without shutting it down.

I have 2 cables that came from the battery, that is inserted into the phone.. And also I have a battery charger, specific for that model.

If I take the battery from the phone and i charge it, is charging.
If the battery is in the phone, and i connect the cables to the battery charger, the battery is not charging, and even is not keep the same level.


So, what is the problem? Why the battery is not charging? The charger cannot give sufficient voltage or amperes for charging the battery and in the same for keeping the phone ruining? Or the charger doesn't interpret correctly the info, because the phone has not an constant consumption?


Thank you!

 

Is it mentioned on the charger and on the battery what are their parameters? You have to know what you need in order to determine if got it or not. The Li-On batteries have specific charging cycle with two phases - constant current and constant voltage. They are also pretty dangerous if handled carelessly. What do you intend to do if your charger or battery is faulty? If you are going to buy a new one, which most likely would happen, there isn't a big deal of the effort.

 

Battery:
3.7v, 4.2v min 1700mAh, 6.3Wh
Battery charger:
Output 4.2v, 350+-50 mAh

I want to do something like this:
http://forum.allaboutcircuits.com/showthread.php?t=51276

So I guess that 350mAh is not sufficent to power up the phone and charge the battery?

What solutin to adopt?