Is fast charging really dangerous for our smartphone battery?

Fast charging, a sought-after feature in smartphones, often raises concerns about its impact on battery health. Does it affect its performance and lifespan? How does it work, and what are the best practices for using it? Let's see how it works, its effects on battery health, and whether you should use it.

How does fast charging impact phone battery health?

Smartphone batteries, using lithium-ion cells, store and release energy by moving lithium ions between electrodes. Charging involves three phases: trickle charge, constant current, and constant voltage. Fast charging boosts the current during the constant current phase, allowing the battery to reach a higher voltage quickly and fill up faster. However, it generates more heat, which can affect battery health.

Lithium-ion batteries naturally degrade over time due to factors like charge cycles, temperature, and charging habits. Fast charging can accelerate degradation by promoting the growth of solid deposits called dendrites on electrodes, blocking ion flow. This can reduce capacity, increase internal resistance, and lead to short circuits or fires. Overcharging, another degradation factor, can be intensified by fast charging, pushing the battery beyond its optimum voltage range.

Smartphone mitigation measures

Modern smartphones use various features to mitigate battery damage. Heat shields, thermal layers, and cooling systems prevent heat from harming the battery. Sensors, software, and chips monitor temperature, voltage, and current, adjusting charging speed accordingly. Smart charging functions optimize charging based on usage habits, preventing overcharging and extending battery life. Some phones even use advanced cooling systems like fans or liquid cooling to reduce heat and stress on the battery.

Should you use fast charging?

While fast charging can potentially harm batteries, the risk has decreased with advancements in smartphone technology. Many manufacturers incorporate precautionary measures, both in hardware and software, to protect batteries. Some smartphones delay or stop charging based on usage patterns, preventing overcharging. Certain models with advanced cooling systems and batteries designed for high power offer fast charging without compromising longevity. For example, some phones can delay charging until an hour before you wake up, as is the case with Google's Pixel, or stop charging when the battery reaches 80% and resume charging when it drops to 20%.

The impact of fast charging on smartphone batteries depends on various factors, including the device's design and the user's charging habits. While caution is advised, especially with prolonged high-power charging, advancements in smartphone technology have made fast charging safer. Using fast charging sparingly, especially when a quick recharge is needed, and opting for slower chargers during leisure times can help preserve battery health. Ultimately, staying informed about your specific device's features and recommended charging practices is key to ensuring optimal battery performance over time.