The original battery, which I didn't expect to find for sale.
In my VAIO SX12, the battery started to perform poorly, so I decided to look for an original replacement. Since VAIO is currently only sold in a limited list of countries, I thought it would be impossible. I disassembled the laptop and saw that I needed the VJ8BPS52A battery. I found this battery in this store and ordered it. Today I installed it in the laptop. It looks just like the original. It's the first charging cycle, but it seems like everything is working perfectly!