Battery life is often the decisive factor for many of us when we go out to buy a laptop. But, power efficiency of laptops hasn’t increased that much, compared to the advancement in processor speeds. And, the struggle for a long-lasting battery that can power up devices for days without recharging continues. PC-maker Lenovo has released a new infographic which predicts when this struggle may end. The infographic even predicts the emergence of batteries that will last for a week.