Unsuspecting mobile phone owners may be left with flat batteries after they update their handsets, despite technology companies promising longer life and better performance from the new software.
The consumer group Which? found that when iPhones or Android phones are updated to the latest version of their operating systems, their battery life can fall by as much as three hours.
A two-year-old iPhone 6 lost 38 minutes of battery life when it was updated to the latest version of Apple’s iOS software, iOS 10. A Google Nexus 6P phone went from 12 to nine hours of battery life when the most recent version of Android was installed.
Both the iPhone and Android software claim that features in the latest versions improve battery life, rather than hurting it.
Mobile phone companies typically release major software updates every year as well as adding smaller changes throughout the year. When an update is released, users are sent notifications urging them to upgrade and are often given no way to revert to the previous operating system, meaning they are stuck with the new software even if they suffer from worse performance.
Which? said that software updates can also mean the memory of tablets and phones falling dramatically due to the extra capacity taken up by more advanced software. A Microsoft Surface Pro 3 tablet lost 30 gigabytes of storage when upgrading to the latest version of Windows – enough for thousands of photos.
The updates often include new features and important security changes that protect users from being tracked or having their details stolen, but early versions can be loaded with bugs.
Which? said mobile phone companies should do more to warn users of the side effects of updating, and allow them to revert to older software if they wish.
The group did find that battery life and storage were improved in some cases. Updating an iPad Air to the latest software improved battery life by two hours and updating a Samsung Galaxy tablet improved it by four and a half hours.
“Given how much we rely on mobile devices, companies should do more to tell us about the possible downsides of updates, as well as the benefits,” Which?’s Richard Headland said.
Apple and Google declined to comment.
This year, Microsoft was forced to pay a travel agent $10,000 (£8,000) after an unwanted automatic upgrade to her computer left it slow and prone to crashing.