CNET asked experts what fast chargers do to our phone’s battery over time and how to extend its life.
As we do more with our phones over more hours, the importance of all-day battery life on a single charge has become one of the key features that an average buyer looks for, after screen size. Battery life is even more important than an excellent camera, according to Kantar’s Worldpanel ComTech Q3 2019 study. The same concern applies to battery longevity over the entire lifetime of your device.
The growing emphasis on battery life is one reason why fast chargers are so ubiquitous. If the battery threatens to drain before the end of the day, refilling the battery fast is the next best thing. A 10-minute charge could make the difference between having to go into an austere power-saving mode or losing power completely before you get home.
Now that fast charging is so readily available for phones, we have questions: What does a high-capacity charger do to a phone’s battery and is there a chance that rapid charging can degrade your phone’s power-storing capability over time?
And while we’re asking, we’d like to know what else we’re doing when we charge our phones that might cause unnecessary wear and tear on your phone’s battery over time.
To discover the answers to our questions, we spoke with several battery researchers and engineers about the effects of quick charging on your phone’s battery life. Here’s what we learned.
MacDailyNews Take: As per Apple’s support pages, your iPhone’s lithium-ion battery uses fast charging to quickly reach 80% of its capacity, then switches to slower trickle charging. The amount of time it takes to reach that first 80% will vary depending on your settings and which device you’re charging. Software may limit charging above 80% when the recommended battery temperatures are exceeded. This combined process not only lets you get out and about sooner, it also extends the lifespan of your battery.
Charge your Apple lithium-ion battery whenever you want. There’s no need to let it discharge 100% before recharging. Apple lithium-ion batteries work in charge cycles. You complete one charge cycle when you’ve used (discharged) an amount that equals 100% of your battery’s capacity — but not necessarily all from one charge. For instance, you might use 75% of your battery’s capacity one day, then recharge it fully overnight. If you use 25% the next day, you will have discharged a total of 100%, and the two days will add up to one charge cycle. It could take several days to complete a cycle. The capacity of any type of battery will diminish after a certain amount of recharging. With lithium-ion batteries, the capacity diminishes slightly with each complete charge cycle. Apple lithium-ion batteries are designed to hold at least 80% of their original capacity for a high number of charge cycles, which varies depending on the product.