FORTUNE -- Ever since buying the first-generation 11-inch MacBook Air three years ago, my wish has been two-fold: make it faster and make it last longer between charges.
Apple (aapl) took care of the performance issues in 2011, when it switched to a faster Intel processor. Paired with flash-based storage, apps launched briskly and zipped along. It was fast enough. Still, battery life remained a sore point for reviewers and critics. The company claimed the Air could get 5 hours in-between charges. In reality, with features like Wi-Fi turned on and brightness near maximum, battery life sometimes fell short, running for as little as 3 hours before having to shut down. For a notebook intended as a travel companion, that's not even juice for a cross-country flight from San Francisco to New York. (And sure, you could seriously dial down the brightness and turn off the Wi-Fi to eke out more time, but doing so meant staring at a pretty dark screen. More importantly, why should users have to do that?)
With the 2013 11-inch MacBook Air, little has changed on the outside -- it's still the same svelte aluminum body -- but Apple now promises what road warriors have wanted all along: all-day battery life. The 13-inch model is rated at 12 hours, and the 11-incher at 9. That's 4-plus hours more than the previous Airs, which if true, means users could use one of these, unplugged, from 9 to 5 and still have juice to spare.
According to Apple, the size of the battery on both the 11-inch and 13-inch Air remains the same. The new energy-saving component, and really the biggest change in an otherwise minor hardware upgrade, is Intel's (intc) newest Haswell processor chip. The Air uses an ultra low-power version of Haswell, ranging from a 1.3 GHz dual-core i5 to an optional 1.7 GHz dual-core i7, called "ULT." In doing so, battery life supposedly gets a major boost without performance taking a hit. (Indeed, thanks to flash storage that's up to 45% faster, users should expect performance at least on par, if not faster than last year.)
I'm sussing out those claims for myself. My review unit is a $1,199 11-inch MacBook Air with 1.3GHz dual-core i5 processor, 4 GB of RAM, and 256 GB of flash storage. So far? It's running like advertised. Apps launch, windows churn, and high-definition video all run a bit noticeably faster. With Wi-Fi on, the display's brightness cranked all the way up, keyboard illuminated, and a few apps open like Spotify and Evernote, the MacBook Air's battery indicator read 8.5 hours of charge left; with brightness ratcheted down to 3/4, the Air predicted 9.5 hours. Chances are those numbers will dip as we continue to put the Air through its paces, but if real-world use ends up anywhere near that, Mac aficionados may have a near-ideal travel companion to consider with this pint-sized notebook.
Check back in to Fortune.com later this week for the full review.