Time for a new battery
Recently my eeePc 900's battery has been struggling, so I figured it was time to actually test how dead it is. I charged it up fully and ran a script to log the battery's charge every 15 seconds. I then unplugged the power and left it downloading files over a wireless network. 36 minutes later it ran out of power.
I then plugged in the power turned it back on and once it had booted up I ran the same script to log the battery levels as it charged up. Turns out it took about 90 minutes to charge up again.
As it now only last half an hour I decided that a new battery was due. So I replaced it with the same spec battery and reran the tests. With the new battery it can run for 3 hours, though it does still take a long time to charge.
As I had the data to hand I decided to run it through gnuplot to produce a nice graph to visualise the differences.