Battery life of the FSC Amilo is OK but not exceptionally good. Especially from a sub notebook I would expect a little more working time when using the battery. This does not represent a scientific test, it is just about my experiences when working with this notebook.
With the WLAN on and the screen on the highest brightness the laptop will not survive 3 hours (approx. 2:45 hours), without WLAN and a dimmed screen battery life can be prolonged. In this case it will last about 3:15-3:30 hours.
My impression is that with Linux battery life is slightly better. With WLAN and a bright screen I can work for about 3 hours, when I dim the screen and switch of WLAN this goes up to 4 hours (3:5o – 4:00).
When I have more information on this or something has changed I will update this. Please do not forget, this is not an objective test, but my subjective impression.