Launched in September 2017, the iPhone X has been available for over two years. Following the iPhone's performance and battery guidelines, the device is expected to lose about 20% of its battery capacity after about 500 charging cycles.Apple explains: "A normal battery can store 80% of actual battery capacity after about 500 full charge cycles when operating under normal conditions. One year warranty service includes warranty if the battery is charged. If the warranty is no longer available, Apple will provide a replacement service. "At this time, many Reddit posts mentioned that many iPhone X models users had a battery drain when the device reached the 80% limit.Although the iPhone X will continue to function after reaching the limit, a battery that is reduced in actual capacity will not only affect the battery life after each charge, but also affect the performance of the device. That's what Apple has been talking about since the 2017 iPhone user scandal.When Apple's performance management feature is enabled, users will see an alert in Settings=> Battery=> Battery Health with the following content: "This iPhone has encountered a sudden power shutdown because the battery could not provide the necessary power. The performance management system was started to prevent this from happening again."Obviously with a device like the iPhone X, reaching the limit of 500 charging cycles is easy, especially if you charge every day. Most people charge iPhones overnight so it's clear that the upper limit will easily be surpassed after two years of use.The best way for users to experience the original performance according to Apple's advice is to replace the battery with a brand new one. Currently, the price of genuine battery replacement after the Apple warranty is expired is 69 USD, if there is a warranty, users will not be charged.