Please be aware that you have the model that was available in Japan only, prior to the model we have in the U.S. The most significant change between the 2000 and 2001 model year was the high voltage hybrid battery. The newer battery has a slightly lower voltage, but higher energy capacity. So you need to get repair and replacement information from Japan for your old model battery. The battery we have is not a direct replacement. If your battery is really dead, you will need to get a replacement from Toyota Japan or hope to find one in a junked Prius that is still good.
Maybe you could find an electrician willing to wire up a new model battery to your car, but the charging circuit might not maintain it correctly. I don't know if they sell the new model Prius in Hong Kong, but a junked new model Prius would at least have a newer battery.
Are you sure the high voltage battery is dead? The PS light wouldn't indicate that, it would indicate a problem with the power steering. Did your Toyota shop say why they think the battery is dead? You should at least verify that the 12 volt battery (in the left side of the trunk) is ok. The Prius cannot start without it, but it's much easier to replace than the high voltage battery.
