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OS updates – the great mobile lottery

We've found mobile phones and tablets that got worse after their most recent upgrade.

Updating iOS or Android is supposed to improve your device. But we’ve found mobile phones and tablets that got worse after their most recent upgrade.

Apple and Google aren’t afraid of making some extremely bold claims when they release their annual mobile operating systems (OS). And the launches of their latest – iOS 10 and Android 7.0 Nougat respectively – were no different.ut if you ever feel that installing a new OS sometimes adversely affecs your phone or tablet’s performance, you’re not alone. We wanted to find out how much you could trust the manufacturers’ claims.

So we sent a selection of top-scoring and popular devices back to our test labs. We retested them to discover how OS updates affect a gadget’s battery life and storage capacity. Alarmingly, we found plenty of cases where the results were worse – not better – than on the previous OS.

Keep reading to see which devices win and lose in the great mobile-update lottery.

Best Buy mobiles – pick your next smartphone from the very finest we’ve tested

Android OS updates retest

The release of the Nougat operating system is staggered across Android devices (see below). Because of this, we largely focused on mobiles and tablets that we’d originally tested on Android 5.0 Lollipop, but had now been updated to 6.0 Marshmallow. The results were a mixed bag.

The highly popular Samsung Galaxy Tab S2 8 tablet lost nearly half an hour of average battery life and more than 2GB of storage when we upgraded it to Marshmallow. Its smartphone stablemate, the Samsung Galaxy S6, lost almost 1GB of storage. And Sony’s Xperia Z5 clocked 1.5 hours’ less web-browsing time from a full charge.

But it wasn’t all doom and gloom for Android users. The Samsung Galaxy Tab A, for example, got a welcome 4.5-hour boost to web-browsing battery time. And the Motorola Moto X Style’s call time increased by almost two hours. Meanwhile, the move to Marshmallow freed up an extra 2.5GB of storage on the Motorola Moto X Force. That’s enough for several films, or hundreds of songs and photos.

We then looked at the switch from Marshmallow to Nougat on the Google Nexus 6P smartphone and Pixel C tablet. The former lost almost an hour of battery life on average, while the latter gained more than an hour. It also lost 1.8GB of storage, though. Clearly, Android updates are a lottery, even on Google’s own devices.

Table notes: Models retested from Android 5.0 Lollipop to 6.0 Marshmallow, except the Google Nexus 6P and Pixel C, which we retested from 6.0 Marshmallow to 7.0 Nougat

Apple iOS updates retest

When it comes to Apple products, results for the move from iOS 9 to iOS 10 are a little more consistent.

The iPhone 6s, 5s and SE, for example, all gained an average of around 15 minutes’ battery life. The iPad Pro 12.9 gained almost two hours’ extra web browsing. However, the same device lost a significant 2.88GB of storage, while the 9.7 -inch iPad Pro gained almost 8GB.

We also have data for the iPad Air 2 and iPhone 6 using iOS 8. Between this and iOS 10, the former gained almost two hours of average battery life. The latter lost 38 minutes.

Table notes: Models retested from iOS 9 to iOS 10

Why isn’t Android Nougat available for my phone?

If you’ve got an Android smartphone or tablet, you may not yet have had a taste of Nougat. That’s because not all Android devices are created equal when it comes to OS updates.

Once Google announces a new version of Android, mobile manufacturers then have to try to make it work reliably on their devices. And if you buy your phone from a mobile-network operator, such as EE or Vodafone, there’s often an additional delay while it makes its pre-installed apps and features compatible.

Manufacturers usually claim it’s not economical for them to upgrade all their phones. And, to a degree, that’s acceptable. But when even top-end devices seem to receive OS support for only a couple of years, you’d be forgiven for wondering whether it’s just a way of encouraging you to buy a new model.

More seriously, older devices miss out on the security fixes that come as part of the updates. This leaves them potentially vulnerable to attacks from viruses and scammers.

Which? expert view – ‘Google and Apple should be more transparent’

Apple and Google dine out on the new features they give you when you update your operating system. They’re certainly welcome – as are the essential security updates that come packaged up with them.

But our data shows it’s a lottery as to how the so-called ‘upgrades’ will affect your battery life and storage. That’s annoying, especially as we’re often given little choice but to update.

We believe companies should do more to explain the possible effects on performance of every OS upgrade. We also think they should let you revert to the old software if you don’t like the new version.

As it stands, the enhanced security that OS updates offer means we still recommend installing them. But don’t necessarily rush to do so. We suggest ignoring the nagging notifications for a few weeks while teething problems are fixed.

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