Smartphones have deeply penetrated our lives and have become an integral part of it. We simply can’t live without our phones, even for 10 minutes. Most people constantly check their phones for notifications – the frequency could be as high as 10-12 times an hour. Since we constantly use our phones, the battery remains a matter of concern for every one of us. The most common question, asked by almost every smartphone user is – Should I charge my phone overnight?
This question is thought provoking at first. We all know that while charging, our phones tend to heat; also since more power is being drawn while charging, this increases the tendency to broadcast stronger radiations. Apart from that, the biggest fear is the battery degradation due to overcharging – most of the rechargeable batteries degrade over time if kept charging for long periods of time – reducing the efficiency, charge holding capacity, output voltage, etc. Also, not very long ago, faulty battery design caused numerous Samsung Galaxy Note 7 devices to explode – and in most of the cases, the phones were on charging when they did.
All of this does raise the question
“Is it safe to charge my phone overnight?”
While people would say no, experts have an opinion exactly opposite of that. Nine out ten mobile enthusiasts, technicians, developers, and engineers will say that it is not a problem to charge your phone overnight. Every smartphone today comes with a built-in battery charge detector, which keeps tracking the charging levels continuously; and once the battery reaches 100%, it cuts off the charge to battery and switches to AC power, and doesn’t use battery power to run. The device will then switch to battery power the second charging is cut-off.
While this may not be completely true for devices older than 15 years, this holds perfectly fine for every smartphone that has been in existence or has been manufactured in the past ten years. All smartphones have a charge detector, which will safely disconnect your battery from external power sources, preventing it from being damaged by overcharging.
To be on the safer side, always keep your phone away from your head at night. It is preferable to keep it at least 5-6 feet away. This helps keep the microwave radiations away from your brain helping you sleep well. It is also advisable to not use the device while charging as this not only affects the quality of charge the phone is receiving but also causes the device to heat up unnecessarily which is very bad for the health of the battery.
If you wish to keep the battery of your device to last long, it is advised by many, that you keep the battery of the phone 40%-80% levels – this prevents the ions from any one side (read anode and cathode) from taking over the majority and helps maintain the battery cycles.
Every battery has an expected number of charge cycles that it can go through before beginning to lose its efficiency. Most Li-ion and Li-polymer batteries used in the phones today have a typical charge cycle of 800-900 cycles. i.e. if you charge your phone once daily, then your battery should be good for around two years. After this, the battery will slowly degrade on its own and eventually lose its charge holding capacity and will have to be replaced.