2. If the battery is still 79%, you can use 1 to 2 hours. If you have used this mobile phone for several years, you can only use it for one hour at most. Or if the battery capacity of the mobile phone is 79%, it will take about four hours at most to fully charge, which means that the battery is worn and needs to be replaced after sale.
When the battery health of Apple mobile phone reaches 80%, it needs to be replaced. Generally, you can consider replacing the battery after 2-3 years of use. Battery health can be seen from the battery health of mobile phones. If the displayed value is lower than 80%, it should be replaced. If it is higher than 80, it can be changed later.