1. Buy 2.0mm female socket (easy to find in some electronic component shops)
Then cut the correct dimensions to fit the charger plug of S3.
Cut to the correct size
There are 3 pins for the connection of the female socket to the battery box, the middle one is no use.
2. Connect the female socket to the battery box via the wires
3. The batteries and the connected socket
As the input voltage of S3 is 9V, so if the input voltage of the battery box is 9V, it must be OK. I have tried to input the voltage to S3 up to 11V through a power supply and it is Ok too. So I tried 8 pcs x 1.25V = 10V and it will be more safer and it works too. Of course you can try 6 pcs x1.5V = 9V Alkaline batteries, it is no problem.
4. External batery box connected to the S3
5. S3 battery removed, connected to the batery box
6. External battery is working on S3, now playing movies on S3 with the whole day is not a problem.
