Why your iPhone battery keeps dying at 25 per cent

You know the drill. You're polishing off your final pint, glance at your phone and see you've got 25 per cent battery left. 

"Great," you think. "I'll nab an Uber, order a takeaway with Deliveroo and cruise on home like a tipsy digital king."

And then, like some crap spell out of Harry Potter - BAM. Your phone dies. That 22 per cent disappeared like water through a sieve. 

What's going on? Why does your phone keep draining that last chunk of battery so quickly? Anecdotally we are hearing this is a problem that has increased significantly since iOS 10 was released. 

So, like the tipsy digital kings that we are, we thought we'd look into how to fix your iPhone battery woes once and for all. 

Identify your battery drainer

If you carry out the above calibration attempt and still find your iPhone dying super quickly, the problem may lie with an app. 

You can easily check which apps are drinking your battery juice: go to Settings > General > Battery and scroll down to see a list of the worst offenders.

Deciding whether or not to uninstall apps is always a balancing act between battery life and utility, but any towards the top of the list that you rarely use are worth binning. One of the 'biggies' may well be Facebook, which drinks through charge in a quest for notifications and location details. As does Tinder, so any of you single men might want to think about swiping upwards to turn that app off while you are going about your day. 

As an aside, a neat way of axing Facebook but maintaining a connection with your social world is to delete the app (gasp) and then set up a shortcut to the mobile version of the network via Safari. Simple, but effective. 

Update everything

Obvious, but overlooked. Apple and app builders are constantly working to improve the efficiency of software, but you can only benefit from these tweaks if you keep everything up to date. 

Head to the App Store, have a poke around updates and see what you're missing.

(Image: iStock)

Recalibrate your battery stats

iPhones work out their own battery lives through a complex set of git wizardry and tech stuff we won't go into. This internal monitoring can occasionally get out of sync, resulting in your phone thinking it's still got 20-something per cent battery left when it in fact only has three or four. 

You can reset this internal clock by doing the following:

• Let your battery drain to zero. Zilch charge left.
• Keep your phone turned off, and recharge your battery to full.
• Once you're at the sweet 100 per cent mark, you're going to want to reset your iPhone. Do this by turning your phone back on with the power cable still inserted, and then holding down the home button and lock button simultaneously. After a few seconds the Apple logo should appear and begin the restart process. 
• On powering your iPhone back up, it should recalibrate its battery levels, leaving you with a much better idea of how much charge your battery really holds.