Since the release of the iPhone 8, all newer iPhone models are capable of fast charging, which means you can get what Apple advertises as 50% charge in 30 minutes.
This is a valuable feature for iPhone users who need a quick boost to their phone's battery when they don't have time to leave their phone plugged in for several hours. However, sometimes, this feature may not work as intended. Here are some ways to troubleshoot the problem.
1. Make sure you are using a MFi certified USB-C to Lightning cable. You need this cable to fast charge your iPhone. For newer iPhone releases (since the iPhone 11 Pro), this cable comes in the box. However, if you have an older iPhone (iPhone 8) or if you lost the original cable, you'll need to purchase a new one. If you decide to purchase from Apple, there's no risk there, but the price can be a bit high. For third-party sellers, make sure that the cable is officially approved by Apple by checking that it has the MFi certification mark. For example, take a look at ZMI's cable and see how it has the Made for iPhone, iPad, iPod label. A cable that is not MFi certified may cause problems when charging.
2. Make sure you have a USB-C PD charger. Since the iPhone 12, Apple no longer provides a charger/power adapter in the box. To fast charge an iPhone, you need a charger with a USB-C port that also supports USB Power Delivery. It usually will say in the product title if this is the case. You can always purchase a new compatible charger directly from Apple, including the 20W USB-C charger. However, smaller and more affordable options are available. We sell several USB-C PD chargers.
3. The USB-C PD charger should support at least 18W charging. Although Apple recommends a 20W charger for best performance, the typical charging time between an 18W and 20W charger is negligible, but a 20W or higher charger may boost Apple's MagSafe wireless charging speed a bit.
4. Fast charging is not a constant charging speed. Do not expect your iPhone to continue fast charging from 0-100%. As your iPhone's battery fills up, the charging speed will begin to taper. Usually past the 50% full mark, you will begin to notice a reduction in charging speed. Around 80% full, the iPhone will switch from fast charging to normal charging. This is not a bug or issue with the iPhone or charger but a normal setting that Apple has configured. It is probably designed to protect the battery's lifespan. For a longer battery life, it is best to keep the iPhone battery level between 20-80% full.
If you are having other issues related to charging your iPhone or need further assistance, feel free to contact us.