The science behind smartphone batteries: a user’s guide

In today’s fast-paced world, our smartphones have become indispensable, with U.S. consumers spending an average of over 4.5 hours on their devices each day, excluding using them for making phone calls.

As these devices become more powerful and integral to our daily lives, both for work and socially, understanding how their batteries work is essential.

Understanding lithium-ion technology

Most smartphones today rely on lithium-ion (Li-ion) batteries, a technology that revolutionized the mobile industry due to its lightweight nature and rechargeability. These batteries store and release energy through the movement of lithium ions between the anode (negative electrode) and cathode (positive electrode). When you charge your phone, lithium ions move from the cathode to the anode. When you use your phone, these ions flow back, releasing energy to power your device.

Li-ion batteries have become the standard due to their efficiency, but they aren’t without limitations. As your phone goes through charging cycles, the battery’s ability to hold a charge diminishes – a process known as battery degradation.

Capacity and performance

Battery capacity, often measured in milliampere-hours (mAh), indicates how much energy it can store. But capacity alone doesn’t determine how long your phone will last on a single charge. Screen resolution, processor speed, background apps and network connectivity (4G/5G) all play significant roles in how quickly your battery drains.

Understanding these factors can help you optimize your phone’s performance. Reducing screen brightness, closing unused apps and disabling unnecessary notifications can extend your battery life. Modern smartphones are also designed to prevent overcharging, making it safe to leave your phone plugged in overnight. A digital ammeter can provide information on the performance of your charger if you think it might not be functioning as it should be.

Battery degradation: why and how it happens

This is a natural process that occurs as your battery undergoes repeated charge cycles. According to Apple, after 500 full charge cycles, a typical lithium-ion battery retains about 80% of its original capacity. Signs of degradation include reduced battery life, slower charging and unexpected shutdowns.

To prolong the lifespan, avoid exposing your phone to extreme temperatures, and consider partial charging (keeping your battery between 20% and 80% charged).

The future of smartphone batteries

As smartphone usage continues to rise, so does the demand for better batteries. New technologies like solid-state batteries and graphene-based solutions promise longer life and faster charging times. Sustainability efforts are pushing for greener technologies and more efficient recycling methods.

By optimizing your battery usage and staying informed about the latest advancements, you can ensure your smartphone remains reliable and performs at its maximum for a greater length of time.