iPhone 13 ProSource: Apple Inc.Apple announced new iPhone models on Tuesday in what is an annual tradition for the company ahead of the holiday shopping season.The new models, called iPhone 13, are not major advances over last year’s models.Last year’s models gained 5G connections and a new, flatter design. This year’s four new models look similar, come in the same screen sizes, have faster processors and have gained several new photography features targeted at skilled users.But Apple did present — and emphasize — one improvement on Tuesday that anyone who picks up the new models will appreciate: bigger batteries and longer battery life.The emphasis on increased battery life during Apple’s launch event on Tuesday highlights the challenges faced by the company that is expected to release a materially better device every year to drive growing sales in a maturing market where major breakthroughs are becoming less frequent.Improvements to screen image, processor speed or camera quality may appeal to some, especially photography professionals, but every year’s changes require a more discerning eye to notice them.All four new models will get at least 90 more minutes of battery life under normal use, Apple said on Tuesday. The biggest and most expensive model, the $1,099 iPhone 13 Pro Max, as well as the best-selling mainline iPhone, the iPhone 13, will get 150 more minutes of battery life than last year’s models, Apple said.For example, the iPhone 12 gets 17 hours of video playback, according to Apple’s website. The iPhone 13 manages 19 hours, which works out to nearly 12% more battery life.Battery life also remains one of the most important features to consumers, according to many polls. In one 2019 poll by SurveyMonkey, 76% of iPhone owners said longer battery life would be a feature that would get them excited to upgrade to a new phone.Another feature that rates highly on polls is storage space. Apple doubled the default storage space on the iPhone 13 to 128GB on Tuesday without raising its price.Apple is emphasizing these improvements as Wall Street wonders if Apple can keep its iPhone momentum up. iPhones accounted for about half of Apple’s sales in 2020 despite efforts to diversify into headphones, accessories, and online services.Apple also faces challenging comparisons to last year’s sales, which were elevated. In the most recent quarter that figures are available ending in June, Apple sold nearly $40 billion in iPhones, up over 49% from the same period in 2020.When Apple releases iPhones that look different, they often see a bump in sales, which some analysts call the company’s “supercycle.” Analysts are already wondering if the iPhone 13 will sell compared to last year’s model, although the iPhone 12 went on sale in October and November, later than this year’s September release date, pushing more sales into the slower summer months.Investors have concerns about a “material moderation in upgrades” to 5G phones following momentum from last year’s Apple releases, JP Morgan analyst Samik Chatterjee wrote in a note distributed shortly before Apple’s launch on Tuesday.In its presentation on Tuesday, the company said the increases are driven by bigger batteries enabled by a internal redesign, as well as Apple tweaking its processors to use power more efficiently.While Apple can’t break the laws of physics — bigger batteries mean more power — its ability to design both the iPhone’s hardware, including its chip and display, and its iOS software means that the company has full control many more of the big power hogs that zap battery life, and can optimize them to squeeze a little more juice.In a challenging sales cycle compared to last year, Apple is giving its customers what they want: more storage space and longer battery life.