New laptops with extended battery life are hitting store shelves. `What these laptops have in common are microprocessors that belong to a new family of Intel chips called Haswell. The chips consume less power than previous generations and promise a 50 percent boost in battery life for watching video. The improvements extend to word processing, Web surfing and other computing tasks as well.They also lack Ethernet ports for wired Internet connections and slots for DVDs. Expect to use Wi-Fi a lot, though USB ports are available to connect devices. Base models come with 128 gigabytes of storage. You can spend a few hundred dollars more for additional storage and faster processors. Put another way, you can unplug your laptop in the morning and go a full day without a charge, with some breaks for meals, exercise and errands. The 13-inch (33-centimeter) MacBook Air, for instance, promises up to 12 hours of battery life. Three Windows machines I tried promise seven to nine hours. For students, that's a full day of cutting classes - and more. For business travelers, that's a cross-country flight including delays.