I tried to google my problem to no avail. I have two battery packs: one 6-cell and one original IBM/Lenovo 9-cell pack. The first one won't last more than an hour and is good for short trips and for use at home and in the office, the heavy 9-cell can last for up 5+ hours and I use it for longer trips. Whenever I take out either of the battery packs out of laptop and put one of them back in I have to connect the AC adapter so I can turn on the laptop, otherwise the laptop remains dead. This fact makes it impossible to take both of the battery packs on a trip, because once I take out the battery I can't turn on the laptop until I get to a place with a power outlet where I can connect the AC adapter to the laptop. I can't seem to find an option in BIOS which controls this behavior. Does anyone has the same problem and/or is there any solution for this? I use the latest BIOS update for my T60.