This blogger's simple trick could save 20 per cent of your phone's battery.

It’s happened to all of us. You’re out, using your phone to give you directions, take photos or keep your hands busy while you wait for a friend – when suddenly, you notice the battery has been sucked dry.

‘Hang on. It was on 80 per cent an hour ago,’ you say. ‘How can it now be at ‘less than 20 per cent’ now?’

It’s a fact that most of us have come to accept. But as one phone user has discovered, there may be a simple way to slow down the impending drain on your phone’s battery.

All you have to do is delete an app. The only problem? It’s a very popular app. In fact, you’re probably using it right now.

Yep, it's the Facebook app and deleting it could save 20 per cent of your phone's battery life, according to Android blogger Russell Holly.

While it's not clear if the same amount could be saved with an iPhone, presumably Apple users would also save a lot.

Holly's claims, made on tech website Android Central, have been backed up by Redditors and a writer for The Guardian.

Guardian writer Samuel Gibbs tested the theory earlier this year.  Gibbs kept his Facebook messenger app, but swapped his regular Facebook one for an app called Metal, which basically acts as the Facebook app, without being the Facebook app.

Another alternative is simply accessing the Facebook website through the Internet app. Or you could just try quitting Facebook. (Good luck.)

Want an app that is worth every bit of your phone battery?  The Mamamia Podcasts app is just that. 

Gibbs said he found that his Huawei Nexus 6P had about 20 per cent more battery over the course of each day of the week he tested it without the Facebook app.

A Reddit user also tested whether the presence of Facebook on his phone made everything else slower. According to his tests, it did.

A Facebook spokesperson told The Guardian in February that they had heard reports of people experiencing speed issues.

"We are looking into this and will keep you posted. We are committed to continuing to improve these issues.”

No word yet on whether any improvements have been made, but for 20 per cent more minutes of Instagram scrolling while you're on the train to work, it might be worth testing it out yourself.

Would you delete your Facebook app to save battery life?