I've been running Ubuntu on my trusty old Satellite A100 since 9.04 without any problems, the battery is still the original and three years old. Now I use the laptop mostly on mains power, but occasionally run it for brief periods on the battery (moving rooms or when the kids snag the cable as they walk past and pull it out).

When running on battery I get no low battery warnings, either from Ubuntu or from the laptop itself. I put this down to the battery being very old, but having got a new high capacity 8800mAh battery I'm having similar problems. There appear to be very few battery saving options in 10.04, the accuracy of the predictions are very low (according to the battery statistics) I've had the laptop spontaneously switch off after 40 minutes, and when I reboot the battery is showing 83% capacity.

The first replacement battery didn't work at all, their replacement works 'kind of' but obviously cutting out without warning is not helpful. I'm wondering if the 8800mAh battery is simply beyond the design specifications of the charging circuit in the A100 which was supplied with a 4400mAh battery pack as standard. Or is this just bad battery management in the OS?

In some laptops I've used previously there has been a battery test in the BIOS but the Toshiba doesn't seem to have any battery related options.

Any thoughts on this?