Many people charge their phones overnight to start the day with a 100% battery, and experts have long warned that this habit reduces battery life.
According to Chao-Yang Wang, director of the Center for Electrochemical Engines at Pennsylvania State University, this is partly true. He notes that if you regularly charge your phone to 100%, the battery will degrade 10-15% faster than charging it at a low level, such as 90%.
Dibakar Datta, associate professor of industrial and mechanical engineering at the New Jersey Institute of Technology, said that leaving the battery plugged in after it's full keeps the battery at a high voltage, leading to "chemical aging".
According to HuffPost, this degradation happens slowly, and phone batteries are quite durable, so users don't need to worry too much. "Batteries are capable of lasting longer than other components in the phone," Mr. Wang said. Users may need a new smartphone for other reasons, such as a poor camera quality or a broken screen, before the battery dies.
“It all depends on individual needs and convenience. If you have an important day, you should charge it to 100% to have more power for longer usage,” Wang explains.
If you have to travel a lot during the day and need your smartphone to guide you, you should charge it fully before going out. But if you stay at home all day and don’t rely on your phone too much, you should only charge it to 85%.
Meanwhile, Dibakar Datta recommends not letting your battery drop to 0% too often, as it can harm your phone’s ability to maintain its charge level. Keeping the battery between 20-80% is ideal, so users can start charging at around 20%.
For better protection, batteries should also be kept at the right temperature. "I think batteries are probably 'afraid' of extreme cold or heat. The damage in such extreme conditions is probably greater than charging to 100% at normal temperatures," said Mr. Wang.
Many smartphones are designed to change the charging speed depending on the weather, and the screen sometimes shows a message that the phone is too hot to charge. Ideally, the phone should be kept at room temperature.
Experts also advise against using fast charging regularly. "Slow charging is better because charging too fast creates heat and can reduce the battery's lifespan over time," explained Datta.
Most smartphones provide information about the battery's health in the settings. Users can also ask a specialist at the store to check this information, and should replace the battery if the battery's "health" is below 80%.