Q: Why does the iPhone battery drain so much? I have an iPhone 6 and consider myself a “normal” user of the iPhone. I have gone to Apple’s website and did everything suggested to slow the drain, but sometimes by 6pm I’m down below 50 perc cent. What else can I do?

A: Battery drain can be caused by a number of factors, including the age of the battery itself. The iPhone 6 was released in 2014, and if you purchased the device around that time and have been using it regularly for three years, the battery may be losing its ability to hold a charge. Having an authorised service provider replace the battery or investing in an external battery are two options for a failing power cell.

If you purchased the iPhone 6 more recently — and have been regularly upgrading its operating system as Apple produces fresh versions each year — your phone’s hardware may not be able to use the latest iOS releases as effectively as the faster processors in newer iPhones. Complaints about lousy battery life often dog new iOS versions, which in turn lead to incremental updates from Apple that are intended to provide “bug fixes and improvements.”

Apple released a significant update to the operating system on October 31, so if you have not installed it yet, upgrading to iOS 11.1 might ease some of the power-sapping issues. This iOS 11.1 update also adds dozens of new emoji characters and corrects a few performance issues. Keeping your apps updated may improve things, too.

You can see which apps and services are using the most power by opening the Settings app and selecting Battery; the information is listed under Battery Usage. Turning on Low Power Mode — and turning off power-hungry features like Background App Refresh, Hey Siri and Location Services (when not needed) can also help.

Microsoft Office Mobile Apps

Q: Do you need a paid subscription to use the Microsoft Office mobile apps? I thought they were free for Android and iOS devices.

A: The ability to use the Microsoft Office mobile apps without having to pay a subscription fee depends on the device you are using — and what you want to do with the programmes. The free touchscreen editions of Word, Excel and PowerPoint allow you to do basic tasks (like create a file and enter text into it) on most smaller tablets and phones.

You do need to sign up for a free Microsoft account to use Microsoft Office Mobile for Android, or the iOS versions of Word, Excel and PowerPoint on an iPhone, iPad or iPod Touch. The files are stored on Microsoft’s OneDrive cloud server.

However, if you have an iPad Pro, you get a full-feature version of the software for a free 30-day trial.

After the trial ends, you’d have to sign up for one of Microsoft’s Office 365 subscription plans. Prices start at $6.99 a month.

If you are working with the free versions of apps and want to unlock the rest of the editing features on an Android or iOS device, you also need to sign up for an Office 365 subscription.

Once you convert to a paid plan, you can do things like track and review changes made to documents, insert page and section breaks, use more colours, make maps out of Excel data, and take advantage of all the tools included in the Office Mobile suite.

A subscription for home or personal use does include other benefits, like one terabyte of OneDrive file storage, desktop applications and technical support.

If the price is too steep for you, Apple iWork, Google Docs, Dropbox Paper and Zoho’s office apps are among the free or inexpensive alternatives.

—New York Times News Service