Windows 7: Laptop vs Tablet

Speaking of battery time, is there a code on batteries that give you an idea of how many hours they will last? I know it depends of how you use the laptop, but I would like an idea of how long I could use the laptop on battery.

Most laptops have it listed in the "Specs" table........it's a best guess, or an average in my opinion as I don't know how they calculate it and come up with a battery life number. Laptops these days would have to be at least 5-7+ depending on what kind you got. A gaming laptop will probably be less.....and an ultraportable energy efficient laptop will probably be more. Also, some come with standard batteries and some come with batteries with more cells. Look in the specs and that should give you a good idea of what you are getting into.