I have a IBM laptop that dims the screen so much, you can't see anything when outside. (Yeah, I have to use my laptop outside sometimes). My new Toshiba laptop only gets 1hr 8mins when running on the battery, with the whole machine active.

Does anyone know a cheap and simple solution to running on portable batteries for say up to 6 hours? (Could I couple 13 regular cells together and plug that into the charging input? Anybody done that?)
Any help appreciated. chrisk@bell.co.za