Apple's controversial new iPhone 11 design may have had some recent improvements, but it is still taking flak. In a new report, "Which?", a highly regarded UK consumer advocacy that is an equivalent to Consumer Reports in the United States, has discovered that Apple is overstating the battery life of their iPhones by a large margin.

"Which? tested nine iPhone models and found that all of them fell short of Apple's battery time claims. In fact, Apple stated that its batteries lasted between 18 percent and 51 percent longer than the Which? results," said Which? in a statement.

They discovered one of the biggest discrepancies is the talk time. Apple claims iPhone XR provides up to 25-hours talk time but in tests done by Which? the talk time only lasted for 16 hours and 32 minutes. The discrepancy was limited to Apple. Which? tested 50 models from five different brands such as Nokia, HTC, Sony, Samsung, and Apple. The experiment showed that only HTC fell below their claims while the other brands outperformed the claims of their manufacturer, with Sony outstood them all with 21% overall score.

"With mobile phones now an essential part of everyday life, we should be able to count on our handsets living up to the manufacturer's claims," said Natalie Hitchins, Head of Home Products and Services at Which? "There are clearly questions here around how long some mobile phone batteries will last and so it's important to make sure you find an independent source of reliable information when buying your next phone."

Apple released a statement following the experiment:

 "We rigorously test our products and stand behind our battery life claims. With tight integration between hardware and software, iPhone is engineered to intelligently manage power usage to maximize battery life. Our testing methodology reflects that intelligence. Which? haven't shared their methodology with us so we can't compare their results to ours. We share our methodology for testing which we publish in detail."

Which? then published their methodology: "To complete its testing Which? charges up brand new, independently purchased phones to full battery and times how long they last when making continuous calls."

Conversely, Apple's description of its methodology is vague:

"Testing conducted by Apple in August 2018 using preproduction iPhone XS, iPhone XS Max, and iPhone XR units and software, on both GSM and CDMA carrier networks. Talk Time tests were conducted over a Voice over LTE (VoLTE) network. All settings were default except: Bluetooth was paired with headphones; Wi-Fi was associated with a network; the Wi-Fi feature Ask to Join Networks was turned off."