The 6 best battery life laptops we've ever tested

Laptops' battery lives have gotten so much better in recent years, and our current top pick lasts 40 hours per charge. That's not a typo. It's frustrating to sit down at your laptop for an afternoon of work, only to realize that it's hovering at two percent battery. Oh, and you forgot your charger at home. Perfect . That's why battery life is one of the most important factors shoppers consider…