iPhone users are just learning of hidden ‘vampire’ setting that drains your battery

If you feel like your iPhone battery is draining quicker than it should, you may want to check your settings for a hidden 'vampire' feature you probably didn't know existed.

We've all been there. You're trying to get home and are struggling on four percent battery. You're in power saving mode, the screen is dimmed, but then just as something crucial is about to happen like calling a friend or getting a taxi, your phone dies. Nightmare.

It turns out that one feature on the iPhone could be draining the battery far more quickly than you would otherwise think. Avoiding this feature could help to keep your phone switched on for longer.

But what exactly is the feature which is so draining on the phone's battery life?

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Well, it's a programme which helps to maintain your internet connection when you're out and about. It's called 'Wi-Fi assist'.

This programme essentially fills in the gaps when your Wi-Fi gets a bit slow and laggy and helps to maintain a smooth connection.

Apple's website says: "For example, if you're using Safari with a poor Wi-Fi connection and a webpage doesn't load, Wi-Fi Assist will activate and automatically switch to cellular so that the webpage continues to load."

This is undoubtedly a useful feature. No-one likes to be stuck there waiting, staring at an empty screen begging for it to load up.

The downside is the impact on a phone's battery life and your data usage.

Good news, though! Fortunately there is a way to switch off Wi-Fi Assist if you want to prolong your phone's battery.

Of course the trade off is that if your Wi-Fi gets patchy then you'll just have to deal with it.

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It's not too difficult to do.

Firstly, you need to go into the main settings page on your iPhone, where all the important bits are.

From there go into the tab marked 'mobile data'. Once you're there, scroll down on the page. You may have to scroll all the way down past the apps which are using data.

You should then see the switch saying 'Wi-Fi Assist'. You can then turn that off.

Bear in mind that this could mean you experience a bit more lag when your Wi-Fi has an interrupted connection. However, it will help to make your phone's battery last longer.

Not only that, but Wi-Fi Assist can also sneakily use up a large proportion of your precious data when you think you're safely on a Wi-Fi network. Turning it off can help you to use less of your data plan as when you're on Wi-Fi it won't sneakily switch on.

The more you know.