On September 10, Apple released the latest iPhone 11, meanwhile, iPhone 11 charging adapter has been upgraded from the standard 5W to 18W. Some people worry that the high-power PD fast charging will shorten the life of the iPhone battery. Is this kind of worry necessary? We will do a deep analysis based on the working principle of the Lithium battery and Apple’s official instructions.
During the charging process, Li+ of the positive electrode is released to the negative electrode through the electrolyte and is embedded in the carbon structure of the negative electrode. The more Li+ is embedded, the larger the battery capacity is. In contrast to the discharge process, the negative electrode Li+ is returned to the positive electrode through the electrolyte. Excessive charging and discharging will cause permanent damage to the positive and negative electrodes. Over-discharge leads to the collapse of the negative carbon sheet structure, and collapse can cause lithium ions to be inserted during charging; excessive charging causes excessive lithium ions to be embedded in the negative carbon structure, and some of the lithium ions can no longer be released.
From the working principle, we can conclude that the main factors affecting iPhone battery life are the using environment and usage ways:
1. When the iPhone is used at high temperatures, it will cause internal polarization reaction of the battery, resulting in permanent attenuation of battery capacity.
2. The iPhone is over-discharged, causing damage to the carbon structure of the negative electrode due to excessive discharge, and the battery capacity cannot be reduced by embedding sufficient lithium ions. That is to say, the iPhone continues to be used under low power conditions, especially when the automatic shutdown is used, which will shorten the battery life.
Returning to the iPhone fast charging technology itself, there is no over-discharge in the charging process, and the possible influencing factor is the charging temperature.
The iPhone PD fast charge uses the 18W 9V/2A protocol. Compared with the standard 5V/1A protocol, both voltage and current all increase, and the faster chemical reaction will cause the battery to heat up. For that, we refer to Apple’s official instructions: The optimal temperature for iPhone battery operation is 0°-35°. Engineers use the Ugreen PD charging kit to charge the iPhone XS. The measured temperature is stable at 30.5°, which is within the normal range.
In summary, PD fast charge technology itself does not affect the iPhone battery life. The PD Charger for iPhone 11. The mains factors are the personal use habits and use environment, such as charging the iPhone after automatically shutting down, watching the video caused the phone temperature is too high, which will significantly accelerate the battery loss, and result in lower battery capacity. Also, it should be noted that all rechargeable batteries are consumables, the lifespan is limited, and the battery capacity will gradually decrease.