For example, certain devices offer “optimized charging” settings that pause charging at about 80% and only complete the charge shortly before the user typically wakes up or begins using the device.
Tại sao iPhone sạc tới 80 lại dừng, nên sạc pin đến 80 hay 100
Heat: Another Major Factor
Heat is another factor that significantly affects battery health. Lithium-ion batteries are sensitive to high temperatures, and heat can accelerate battery degradation.
Charging a phone to 100% while it is also generating heat—such as during gaming, video streaming, or using heavy applications—can increase the stress on the battery even more. In addition, keeping a phone plugged in under a pillow or blanket while charging can trap heat and worsen the problem.
To reduce battery wear, it is best to charge the phone in a cool, well-ventilated place and avoid heavy usage while it is charging.
Why Overnight Charging Isn’t Always Ideal
Many people have the habit of plugging in their phones before going to bed and leaving them charging overnight. While smartphones today include protective charging circuits that prevent overcharging, the battery still spends several hours at or near 100% charge.
This prolonged high-voltage state contributes to long-term battery wear. Over months or years, this can lead to noticeable battery degradation, causing the phone to lose capacity faster than expected.
Using smart charging features or unplugging the phone once it reaches around 80–90% can help minimize this effect.
Battery Lifespan and Charge Cycles
Battery lifespan is often measured in charge cycles. A charge cycle represents the total usage of 100% battery capacity, though it does not need to occur in a single charge. For example, using 50% of the battery one day and another 50% the next day equals one full cycle.
Most lithium-ion batteries are designed to maintain good performance for around 300 to 500 charge cycles, after which their capacity gradually declines.
Frequent charging to 100% can increase stress during each cycle, potentially accelerating the rate at which battery health declines.
