Charging Safety: Can You Leave Your Phone Charging Overnight?
Late at night, your mobile phone is quietly charging on the bedside table, and the dim light of the screen and the breathing light flash alternately - this is a bedtime ritual that modern people are familiar with. According to relevant authoritative reports, 78% of urban people are accustomed to charging all night, but few people know that such seemingly ordinary behavior may make the charger a lurking "bedside bomb". Next, this article will deeply analyze the unknown hidden risks behind long-term plugging in, and take you to re-understand the "trivial matter" of mobile phone charging
Leaving the charger plugged in for a long time can easily cause accidents
1. Triple chain of fire hazards
No-load loss and heating: Even if the mobile phone is not connected, the internal transformer of the charger will still generate 3-5W no-load power consumption, and the continuous heating can reach 45℃
Aging of electrolytic capacitors: Long-term power supply causes electrolyte evaporation, and the capacitance decays by 8%-12% each year. Increased leakage current may cause short circuits
- Real case: A fire in an apartment in Shenzhen in 2022 was identified by the fire department as caused by internal breakdown of a charger that was plugged in for a long time
2. Equipment life reduction
- Surge impact: When the grid voltage fluctuates, the undisconnected charger is the first to be affected, and the probability of internal MOS tube breakdown increases by 3 times
- Standby power consumption: A single charger consumes about 2.5 kWh of electricity per year, which is equivalent to continuously lighting a 15W light bulb for 166 hours
Should I plug in the phone or the power supply first when charging?
Current surge protection guide
1. Correct order
plug in the charger first → then connect the phone → finally connect the power supply
2. Scientific basis
Avoid voltage surges at the moment of plugging and unplugging (up to 10 times the working voltage)
Huawei laboratory tests show that the wrong order will shorten the life of the charging IC chip by 30%
3. Reverse operation risk
plugging the phone first may cause arc discharge on the Type-C interface, and the contact oxidation speed will be accelerated by 200%
Does using up the battery before recharging protect the battery?
Misconceptions about deep cycling of lithium batteries
Unlike nickel-metal hydride batteries, deep discharge of lithium batteries (<20%) will lead to:
Intensify the peeling of the negative electrode graphite layer
Trigger over-discharge protection and cause battery dormancy
Optimal charging range
- Keep the battery level between 20% and 80% (Tesla's battery management system also uses this strategy)
- Shallow charging and discharging (30%-50% each time) can extend the battery cycle life to more than 1,200 times
Conclusion
When the phone is fully charged, please disconnect the charger immediately - this simple action can reduce the risk of fire by 67% and extend the life of the charger by 3 years. Remember:
Use a smart power strip with overload protection
Clean the oxide on the charger pins with a brush every quarter
It is recommended to retire old chargers that are more than 2 years old
When you see the charger indicator light flashing alone in the dark, please press the power strip switch decisively. Your safety awareness is the best "explosion-proof device" to protect your digital life.
