So, your iPhone doesn't work like it used to. Maybe it has slowed considerably, or it powers off prematurely.
The good news: You might not need to splurge for a new device. It could just be your battery.
To check quickly, search for "Battery" in Settings. A small notice will appear at the top of the device to indicate if it needs to be replaced.
If the notice appears, you have three options: Get Apple to replace the battery, pay a third-party professional to help or replace the battery yourself.
Here's what to expect for each option:
Get Apple to replace your iPhone battery
Apple will cover the cost of a new battery if it's defective and the phone is under warranty. A new iPhone is only under warranty for a year after you purchase it. (You can extend that period by paying for an AppleCare plan.)
But if your battery is showing regular signs of wear and tear, you'll have to pay $79 for a replacement from Apple. You can mail your phone to an Apple (AAPL) repair center or drop it off at an authorized Apple service store. Both options will take 3 to 5 days.
It's important to note that Apple admitted in late 2017 that a software update deliberately slowed down older phones in some situations to extend battery life. To make amends, the company temporarily dropped the price of replacement batteries for the iPhone 6 and earlier models to $29. The price will go back up to the usual $79 in 2019.
Related: Global backlash spreads over Apple slowing down iPhones
Go the third-party route
If you don't want to wait a few days, a faster option is to use a third-party service, such as iCracked or your nearest phone repair shop.
But be wary of letting companies other than Apple access your iPhone unless it's no longer under warranty. Once an "unauthorized service" opens your device, Apple will no longer repair your phone free of charge under its warranty.
A battery fix from a third-party company can cost $50 to $80.
Related: Apple's iOS 11.3 update gives you control over iPhone slowdown
Replace the iPhone battery yourself
If you're comfortable replacing your own iPhone battery, you can purchase a battery replacement kit online.
The kits can cost as little as $10 on Amazon (AMZN). Videos on YouTube will walk you through the process.
But buyer beware: if you haven't replaced an iPhone battery before, it might be best to leave it to the pros. Apple builds iPhone batteries deep into the device. They are accessible only by removing the back of the phone, which is held shut with proprietary screws.
-- Heather Kelly contributed to this story.