Power cut? How to make your smartphone battery last longer

Why knowing how to conserve your phone's battery could be just as important as owning a power bank.

The UK Government has recently launched its "Be Ready campaign" (https://www.gov.uk/government/news/households-encouraged-to-take-small-simple-steps-to-stay-prepared-in-an-emergency), encouraging households to think about how prepared they would be if essential services were disrupted. Among its recommendations is a sensible one: keep a charged power bank available in case the electricity supply fails.

But something struck me when I read that advice.

What about making the battery charge we already have last longer?

After all, there's little point in having a fully charged power bank if we're unnecessarily draining our phone's battery in the first place.

Most of us charge our smartphones almost without thinking. We plug them in overnight, top them up during the day and rarely worry about running out of power. But what happens when plugging them in is no longer an option?

Our smartphones have become much more than telephones. They're our cameras, maps, diaries, news sources and, importantly, a means of contacting family and friends.

During a prolonged power cut, conserving battery power could become surprisingly important.

The good news is that a few simple changes can make a considerable difference.

Start preparing before you need to

The worst time to start exploring your phone's battery settings is when the electricity has already gone off.

Spend a few minutes familiarising yourself with the options available. Modern Android phones and iPhones have built-in features designed to reduce power consumption.

Find out where they are and how to activate them.

And, of course, if you own a power bank, keep it charged. Check it occasionally rather than discovering, when you need it most, that it's completely flat.

It's also worth downloading useful information in advance, particularly offline maps and essential documents. Keep a paper copy of important telephone numbers, too, in case your phone becomes unusable.

Let your phone do some of the work

Perhaps the simplest and most effective step is to activate your phone's battery-saving mode.

On Android devices, this is generally called Battery Saver, while iPhones have Low Power Mode.

These settings reduce certain background activities, limit some visual effects and help extend the remaining charge.

Some phones offer even more restrictive options. Google's Pixel phones, for example, have an Extreme Battery Saver mode, which pauses most apps while allowing selected essential ones to continue working.

You might notice that some functions become slower or less responsive, but that's a reasonable compromise when battery life matters.

Turn down the brightness

Your smartphone's screen is one of its biggest consumers of electricity.

Reducing the brightness can make a noticeable difference, particularly if you're someone who normally keeps the display fairly bright.

Shortening the time before the screen switches off is another useful measure. There's rarely any reason for it to remain illuminated for several minutes after you've finished using it.

If your phone has an Always-on Display feature, consider disabling it temporarily.

These are small changes, but their benefits accumulate.

Think about what your phone is doing

Even when you're not actively using your smartphone, it may be busy.

Apps can refresh in the background, notifications arrive, location services operate and accounts synchronise information.

Not all these activities are necessary during a power cut.

Consider restricting background activity for non-essential apps, reducing unnecessary notifications and switching off features you're not using.

Bluetooth, for example, can be disabled if you don't need a connected accessory. However, there's no need to switch everything off indiscriminately; modern phones manage many of these functions quite efficiently.

The aim is to eliminate unnecessary activity rather than make your phone unusable.

Stay connected, but use your phone wisely

This is where a little judgement becomes important.

Airplane Mode can significantly reduce power consumption because it disables normal mobile network connections. But it also means you won't receive ordinary calls or text messages while those connections are disabled.

During an emergency, remaining contactable may be far more important than squeezing another hour out of your battery.

If you need to conserve power while remaining available, keep mobile connectivity enabled but avoid unnecessary browsing, video streaming and lengthy calls.

Poor mobile reception can also drain the battery more quickly as your phone attempts to maintain a connection.

Where reliable Wi-Fi is available, it may be more efficient than mobile data, although this depends on the circumstances. Remember that your home broadband equipment may stop working during a power cut.

And don't assume that mobile networks will necessarily remain operational throughout a prolonged outage.

Give your phone a rest

If electricity is unavailable for an extended period, consider using your smartphone only when necessary.

Avoid streaming films, playing demanding games or repeatedly checking social media.

Instead, check for important messages periodically, use your phone for essential communications and leave the screen switched off between uses.

If you're somewhere safe and don't need to remain immediately contactable, switching the phone off for a while is another option.

Temperature matters too. Excessive heat can accelerate battery drain and cause damage, while extreme cold can temporarily reduce performance. Keeping your phone at a moderate temperature is sensible at any time.

And one final thought: keep a separate battery-powered or wind-up torch handy. Using your phone as a torch unnecessarily consumes valuable battery power.

A useful habit, not just an emergency measure

There's another benefit to all this.

Learning how to manage your smartphone's battery can be useful when travelling, spending long days sightseeing or simply finding yourself away from a convenient charging point.

And although reducing charging frequency may save a little electricity, the financial saving for an individual smartphone is relatively small.

The real benefit is having power available when you need it.

None of these suggestions requires specialist knowledge, expensive equipment or a complicated emergency plan.

Just a few minutes spent understanding your phone and making some sensible adjustments.

A power bank gives your phone more energy. Knowing how to conserve that energy could be just as important.

Here's a quick reminder.

Further information

The following official sources provide additional practical advice:

- "UK Government – Be Ready: Power cuts" (https://beready.campaign.gov.uk/be-informed-about-hazards/power-cuts/)

- "UK Government – Be Ready: Emergency preparations" (https://beready.campaign.gov.uk/be-ready-for-emergencies/)

- "Google – Get the most life from your Android device's battery" (https://support.google.com/android/answer/7664692?hl=en-GB)

- "Apple – If your iPhone or iPad battery drains too quickly" (https://support.apple.com/en-euro/120745)

About the author

Mike Young is a writer, blogger, history graduate and smartphone photographer who spent most of his working life as a dental surgeon before turning to writing and photography.

Through Mike on the Move, he shares his enthusiasm for travel, places and photography, encouraging readers to enjoy the experience rather than simply tick off destinations. He also writes about history in his companion blog, Mike Young Through Time.

© Mike Young 2026