Binary package “battery-stats” in ubuntu oneiric

collects statistics about charge of laptop batteries

 This package provides battery-stats-collector, a daemon which will periodically
 collect statistics about the charge of the batteries present.
 .
 It also proves a binary called battery-graph, which can be used to generate
 qplot graphs about the battery charge/discharge patters over time
 .
 Note: This requires APM or ACPI to be enabled and working in your kernel.