Many iPhone users like to charge their devices to 100%, probably because it is the satisfying number that ensures your device will last as long as possible, but it is not something you should do on a regular basis.
Most modern electronics, including the iPhone, use Lithium-Ion batteries, and their capacity is limited to a certain number of changes or cycles before degrading.
To see how much your battery has degraded, navigate to Settings, Battery Settings, and Battery Health.
Because your battery is at 98 percent of its full capacity, this means that 2% of your battery cells have worn out from being charged and discharged over the years.
We want to avoid wearing out our batteries as much as possible, which is why charging all the way to 100 percent and allowing the battery level to drop to 10% or less is considered bad practice.
Deep discharges deplete lithium battery cells faster than charging to 80 or 90 percent and then returning it to its charger by the time it reaches 30 or 40 percent.
This not only ensures that you get the most battery life out of your iPhones for as many days as possible, but it also prevents performance issues caused by deeply integrated batteries.
And Apple attempts to alleviate these issues with software features such as Optimize battery Charging, in which the iPhone will wait to charge past 80 percent until it knows your rate of use based on your charging routine, so it won’t set it to 100 percent for hours at a time, but if that does happen, you actually receive a notification that says your iPhone should be removed from power and discharge to impair performance.
Deep discharges, on the other hand, have a negative impact on the battery, which is where low power mode comes in. At 20%, your iPhone will automatically start drawing performance and background tasks to prevent the battery from draining any further. This means more battery life for the user.
However, it also means that the device is more likely to be connected to power before reaching an extremely low battery percentage.
So, when possible, keep your battery level between 40 and 80 percent so that when you need every minute of battery life on those busy days, your device will be there to deliver.