If your iPhone 5 battery is acting up, it might be covered under warranty. For those who prefer to go it alone, iFixit covers the steps on how to replace the battery yourself. Not only are iPhone 5 batteries available for $10 online, the repair can take as little as 15 minutes if you're already comfortable working with your iOS hardware.
A few tools are necessary, including an iPhone penalobe screwdriver, Phillips #00 screwdriver, plastic opening tools and a small suction cup. Of course, iFixit sells a Pro Tech Toolkit designed to help the intrepid do-it-yourself fan to open and repair a multitude of modern electronic devices. These items can also be purchased individually to help safely gain access to the insides of your iPhone 5.
Remember, any self-repair will void your Apple warranty and make visiting the Genius Bar for service or AppleCare impossible. When it comes to the actual battery replacement, after removing the two pentalobe screws the front display panel is popped off the chassis using a suction cup and plastic opening tool. A couple of steps later and the old battery can be pried off of the back panel of the iPhone 5 to make room for the new unit.
iFixit provides a complete repair manual on their website, showing step-by-step how to replace the iPhone 5 battery for interested parties. Besides removing a few screws and component connectors inside the iPhone 5, the battery replacement itself is one of the more straightforward repairs. Still, perform any out-of-warranty work on your iOS device at your own risk. As always, thanks to the folks at iFixit for providing such detailed instructions.