In the world of lithium-ion batteries, smartphones take center stage.
Yet they’ve also sparked an ongoing debate: Is prolonged (or overnight) charging wreaking havoc on your battery?
A number of factors determine the lifespan of a phone battery, including its manufacturing age and chemical age. The latter refers to the gradual degradation of the battery due to variables such as temperature fluctuations, charging and discharging patterns, and overall usage.
Over time, the chemical aging of lithium ion batteries reduces charging capacity, battery life and performance.
According to to Apple:
A normal battery (iPhone) is designed to retain up to 80% of its original capacity after 500 full charge cycles when operating under normal conditions.
The research found a 2019 smartphone battery could, on average, undergo 850 full charge/discharge cycles before falling below 80% of its capacity. This only means 80 percent of the battery’s initial capacity remains after approximately two to three years of use. At this point, the battery will start to drain noticeably faster.
Should you charge your phone overnight?
Charging times vary depending on the battery capacity of your device (larger capacities require more time) as well as how much power your charger supplies.
Charging your phone overnight is not only useless, this also accelerates the aging of the battery. Full charge cycles (ranging from 0 percent to 100 percent) should be avoided to maximize the life of your battery.
Charging your battery up to 100% too frequently can negatively impact the overall battery life.
Likewise, keeping iPhone at full charge for extended periods of time can compromise the health of their battery.
Can your phone be overcharged?
In theory, lithium-ion batteries can be overcharged. This can lead to safety risks such as battery overheating and fire. The good news is that most modern phones have built-in protection that automatically prevents the battery from charging beyond 100%, preventing damage from overcharging.
However, whenever a battery drops to 99% (due to apps running in the background), it “maintenance charge” : it will start charging again to maintain a fully charged state.
Trickle charging can wear out a battery over time. This is why many manufacturers have features to regulate it. Apples iPhone offer features to delay charging beyond 80 percent. Samsung’s Galaxy phones offer the option to cap charges at 85 percent.
Can your phone explode from charging?
It’s very unlikely that your smartphone will explode from overcharging, especially since most phones now have automatic overcharge protections.
Lithium-ion phone batteries overheating when the heat generated during charging cannot dissipate. This could cause burns or, in extreme cases, cause a fire.
Using an incorrect, defective or poor quality product charger or cable can also lead to overheating, fire hazards and damage to the phone itself.
Tips to Improve Your Battery Life
Although your phone likely has built-in safety mechanisms to protect its battery, taking a careful approach will help it last even longer. Here are some ways to protect your phone battery:
install the latest software updates to keep your phone up to date with the manufacturer’s battery efficiency improvements
use original or certified power chargers, as the power output (amps, volts and watts) in off-market chargers may differ and may not meet the required safety standards.
limit your load to 80 percent of full capacity and don’t let it drop below 20 percent
do not leave your phone charging for an extended period of time, such as overnight, and unplug it from the power source if the battery reaches 100%
keep your phone in a well ventilated area while it is charging and avoid placing it or the charger under a blanket, pillow, or your body while connected to a power source
Monitor your battery health and use it to identify unusual trends, such as excessive charging time or rapid discharge
If you notice that your phone is heating up excessively or has a bulging or swollen back, contact an authorized service center to check and repair it.
If you want specific details about your phone and battery, your best option is to follow the manufacturer’s guidelines.
Ritesh Chugh is an Associate Professor at CQUniversity Australia. This piece first appeared on The conversation.