Should I keep my phone charging all the time?
Many people have the habit of leaving their phones plugged in to charge overnight or continuously while working, but does this affect battery life and device safety?
If you own a device with a built-in battery, you need to understand that it is a consumable component, meaning that its ability to charge and store energy will gradually decrease over time. This is due to many factors such as input current intensity, temperature changes related to voltage, as well as the natural chemical life cycle inside the battery. Therefore, smartphone users often wonder whether they should leave their device plugged in to charge continuously.
In fact, this is completely safe if you use the original charger that came with the phone or from a reputable brand. Newer phones have many built-in battery protection mechanisms, while the charger also has its own hardware protection layer. However, technology experts note that continuous fast charging can affect battery life.
Fortunately, most fast chargers today, even those with capacities as high as 80W, are equipped with systems to protect against overheating, overvoltage, undervoltage, and overcurrent. Thanks to that, whether you are using your device or leaving it on standby, plugging it in for a long time does not pose a significant risk.
Some smartphone models even have a split-charge feature, which automatically cuts off power to the battery and only supplies power directly to the device when needed, helping to minimize battery wear over time.
How does a phone control heat when charging continuously overnight?
Smartphone manufacturers apply many protective measures to ensure safety when charging for long periods of time. Apple claims that the iPhone will automatically stop charging when the battery is full, even if the charger is still plugged in. Charging will only resume when the capacity drops below 95% due to background power consumption.
Samsung also uses a similar mechanism, calling it “maintenance charging,” with intermittent charging cycles to ensure the battery is always full when the user unplugs it. According to the company, there is “absolutely no” risk in leaving it plugged in overnight.
Another common concern is the heating of lithium-ion batteries during charging. High temperatures can certainly affect battery life, but the increase is much smaller in smartphones than in electric car batteries.
Samsung notes that while technically unplugging the battery when it reaches 100% can extend its lifespan, the actual benefit is negligible. Thanks to the control chip and thermal sensor, the device will stop absorbing energy when the battery is full.
However, environmental factors still play a role. Fast charging can make the device warm, but the bigger risk comes from ambient temperature. Apple warns that charging an iPhone in an environment above 35°C can permanently reduce the battery life.
Potential dangers of cheap phone chargers
UK electrical safety organisation Electrical Safety First has recently published a report warning of the serious risks posed by counterfeit chargers, calling them a “particularly dangerous threat” that can lead to fires, electric shocks or damage to devices. Laboratory testing has shown that these poor quality products pose a significant risk to both users and connected devices.
Counterfeit chargers often lack key components, have faulty circuitry, and substandard insulation. Damaged insulation can cause voltage to spike from 5V to 240V, causing serious damage to the phone. Independent testing has found that 98% of cheap chargers fail mechanical and stress tests, meaning they are “completely unsafe” to use.
The difference in component quality is also evident. While genuine chargers typically have around 60 components, many counterfeit models contain as few as 25. The use of substandard capacitors, incorrect component spacing, poor wiring, and poor routing design are common faults. Poor-quality capacitors alone can fail at any time, creating a potentially fatal electric shock hazard, according to the report./.