Mugen Power, provider of quality third-party batteries, has released an extended battery for the Sony Ericsson Xperia Pro. The 3400mAh capacity battery is more than double the stock 1500mAh battery and will set you back $84.95. As you can imagine a battery of this size requires a larger battery cover, which is provided.
Also, the company has released another extended battery for the Xperia arc and Xperia arc S. It had already released a 1700mAh and 4500mAh battery previously and has now added a 3200mAh capacity battery to its stable. This particular one will set you back $84.95.