I got the solution i think.

I put cyanogenmod on it.

this is very easily done with the cyanogenmod installer.
CM also comes with Clockworkmode recovery (a type of bootloader).
In here you can go to advanced settings and reset battery stats.
this worked for me.

you can also try to lower the screen brightness. this seemed to work for me also.

- - - Updated - - -

I got the solution i think.

I put cyanogenmod on it.

this is very easily done with the cyanogenmod installer.
CM also comes with Clockworkmode recovery (a type of bootloader).
In here you can go to advanced settings and reset battery stats.
this worked for me.

you can also try to lower the screen brightness. this seemed to work for me also