Question: When I buy a Dell Laptop, I get the following choice for battery: (Lithium-Ion main battery with X cells and Y Wh [included in price/at additional $] Lithium-Ionen-Hauptakku mit 4 Zellen und 24 Wh [Im Preis enthalten] Lithium-Ionen-Hauptakku mit 9 Zellen und 85 Wh [zuzgl. CHF 120.01] Lithium-Ionen-Hauptakku mit 6 Zellen und 46 Wh [zuzgl. CHF 30.00 I figured that I can calculate that a 86 Wh offers +254% of the 24 Wh lifetime, but... Is there any way to calculate to what battery time this amounts in hours ? I mean how many hours will the 24 Wh last (at normal operation - eg. writing a document - not watching video), else the +254% is a pretty useless number... Also anybody knows whether 4 cells means 4 times 24 Wh, or 24 Wh in total?