Accoring to the datasheet (http://uk.ts.fujitsu.com/rl/servicesupport/techsupport/lifebook/AMILO/Amilo-L/Downloads/ds-amilo-n-li-3710.doc) the battery lasts an absolute maximum of 3 hours 10 mins but computer manufacturers do not usually use real world tests here. There is a section under the max ba...