0659 GMT April 03, 2020
Consumer watchdog Which? tested nine iPhone models and found that the battery life of all of them fell short of the time stated by the tech giant, Mirror reported.
iPhone XR was the worst performer of those analyzed, lasting for 16 hours and 32 minutes when Apple said it can last for up to 25 hours in some use cases.
Overall, Apple stated that its batteries lasted between 18 percent and 51 percent longer than the Which? results.
Apple said in response that it stood by its own measurements and argued that lab-based tests often did not reflect how a battery performs in the real world.
Battery performance can be affected by a number of variables, including a phone's connection to data or Wi-Fi networks, other apps in use, and even external factors such as temperature.
"With tight integration between hardware and software, iPhone is engineered to intelligently manage power usage to maximize battery life," the company said in a statement.
"Standalone battery lab tests rely on a setup that tries to replicate normal usage, but often don't reflect how a battery performs in the real world.
"Which? have chosen not to share their criteria so it is impossible for us to judge their findings."
Which? also tested the battery life of popular phone models from several other big brands, including HTC, Nokia, Samsung and Sony.
The watchdog said the testing involved charging brand new, independently bought phones to full battery and measuring how long they lasted when making continuous phone calls.
HTC phones were also found to offer slightly shorter battery life than the company's official guidelines suggested — around five percent less.
In contrast, the watchdog claimed the devices it tested from Samsung, Sony and Nokia over-performed compared with manufacturer suggested battery life.
"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, Which? head of home products and services.
"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."