Battery uses weird Sony Energytec US103463 prismatic cells — haven’t found a suitable replacement cell — let me know if you have a source; until then, it’s filed under “battery”.
I love that laptop, and it’s great battery life. I kept asking myself why no-one makes new slower, low power laptops with new technology (except they’re moving towards it again with the XO and eeePC). The versa gave me 7 hours of portable computing (or more with standby), while most new laptops give you 3 hours. I couldn’t find anything smaller than the versa for a good price when I got a new laptop in 2005.