How long is the life of Apple's mobile phone?

If the battery capacity is less than 80%, it needs to be replaced.

When your iPhone is charged more than 500 times, that is, after using the iPhone for about 14- 18 months, the battery life will be reduced and the capacity will reach about 80%. At this time, you can consider changing the battery. Moreover, Apple stipulates that if the battery efficiency is lower than 80% during the warranty period, the battery can be replaced for free.

Battery capacity is one of the important performance indicators to measure battery performance, which indicates the amount of electricity discharged by the battery under certain conditions (discharge rate, temperature, termination voltage, etc.). (JS- 150D can be used for discharge test), that is, the battery capacity, usually in ampere hours (abbreviated as A H, 1A H = 3600c).

Factors affecting battery capacity:

1, the effect of discharge rate on battery capacity;

The capacity of lead-acid battery decreases with the increase of discharge rate, that is, the greater the discharge current, the smaller the calculation capacity of the battery. For example, a 10Ah battery can be discharged for 2 hours with 5A, that is, 5× 2 =10; Then 10A can only discharge for 47.4 minutes, that is, 0.79 hours, and its capacity is only 10×0.79=7.9 ampere-hours.

Therefore, for a given battery, discharging at different rates will have different capacities. When talking about capacity, we must know the discharge rate or rate, which is simply how much current is discharged.

2. Influence of temperature on battery capacity:

Temperature has a great influence on the capacity of lead-acid batteries. Generally, as the temperature decreases, the capacity decreases. The relationship between capacity and temperature is as follows: CT1= ct2/1+k (t1-t2). T 1, t2 is the electrolyte temperature, k is the temperature coefficient of capacity, Ct 1 is t 1 is the capacity at temperature (Ah), and Ct2 is the capacity at temperature t2 (Ah). In battery production standards, the temperature is usually designated as the rated standard temperature.

If t 1 is the actual temperature and t2 is the standard temperature, then the negative plate is more sensitive to the influence of low temperature than the positive plate. When the temperature of the electrolyte decreases, the viscosity of the electrolyte increases, the ion is greatly resisted, the diffusion ability decreases, and the electrolyte resistance also increases, which increases the electrochemical reaction resistance, and some lead sulfate can not be converted normally, which leads to the decrease of the battery capacity.