Should You Really Charge Your Phone Overnight? All The Details You Need To Know

We have reached that point in our lives where we can’t imagine a single minute of our day without the smartphone. We constantly have something to do on it and hence this leads us to completely recharge our phone mostly at night. However, there is one catch to it that constantly worries us; the overcharging factor or the explosion of battery while we are asleep. But can that really happen?

What Can Happen To Your Phone If You Charge It Overnight?

Let’s be straight up with the most popular myth - your phone doesn’t overcharge or starts going beyond 100%. Phones of today are ‘smart’, especially in terms of how they now have built-in protection chip which stops the battery from overcharging.

But don’t be happy so soon as the threat no lies in trickle charging. This lowers the current matching the discharge rate in order to keep the battery at 100%. So, when you keep your phone at charge overnight, it keeps the battery functional which leads to more recharging and short lived batteries eventually.

The Big Issue With Overnight Charging

You may have seen smartphone giants like Huawei or Samsung boasting about Lithium-ion batteries. Yes, the ones that are claimed to have better rechargeable ability and can even charge up to 80% within a few minutes, all with the help of fast charging technology. If we compare the time to charge today’s smartphone (which is around 1-2 hours) to the number of hours you sleep and leave your phone for charging overnight, the difference is just too much for the battery to handle.

This puts stress on Lithium-ion batteries even if they are known to be the champion. But as we all know even the champions have some weaknesses, the case is just the same over here as well. Li-ion suffers when left to charge above 100%. In fact the worst starts to happen if you do it constantly month after month. Although you might not see the impact on battery health in the short run but it does decline the capacity of your battery if you want to use your phone for a number of years.


Source: Batteryuniversity.


Another most important issue that phone owners often ignore relates to how Li-ion batteries should not be charged to 100% full. It may come off as a surprise to many but anything outside 20% - 80% is just going to degrade the battery and we are going to explain how.

The Impacts of Prolonged Charging

Li-ion batteries are bound to decay right from the time you first start using your new phone and anything you do from cycling to discharging and charging, it’s life span will go down anyways. While this might have raised a thought in your mind about how can we hasten or delay the process, we have got you covered for this as well.

When you put your new phone on charge, the lithium ions start to swim across the cathode to anode, which is pretty normal. However, this is where the irreversible damage starts to take place in the form of how electrically insulating rock salts form and build up over the cathode. This process overall shrinks the capacity of battery.

Unfortunately that is not all. The buildup in fact blooms like wildflower at higher battery levels and temperature. Thus, maintaining a higher battery level degrades the battery faster, which eventually is more harmful than cycling of a battery. The problem in the end lies in high state of charge.

For When Your Phone Ends Up All Hot After Overnight Charging

By now, you may be familiar with the fact that heat too damages the battery capacity. It doesn’t matter where you charge or for how long you charge, your phone can get hot due to a number of reasons and you then get to face the consequences in the form of declining battery. Majority of heat is stoked up before reaching to 100% on fast charging, whereas the low voltage of trickle charge makes the heat negligible.


As all the matters are discussed in detail, here are now some precautions that can help you in protecting your battery.

How Can You Delay Battery Degradation Especially If You Have A Habit Of Charging Overnight

1. Make Up A Routine
It’s time to plan your nighttime charging. By that we mean if you have a fixed bedtime, make sure you charge your phone 2 hours before that (or less if you have a fast charger and your phone is compatible with it). Moreover, make sure you don’t use your phone much during the charge as heavy-duty apps can make it hot again.

2. Slow and steady
Choose a slow cable/charger over fast charging. This will lower the heat that arises from fast charging and may take a little longer for your phone to charge but your phone will be safe.

3. Just A Bit of Care
This one is simple; unplug when you wake up. If you wake up for bathroom, nightmares or you are just an early riser then unplug your charger as the first thing.

4. Smart Cable
You can also opt for smart charging cable that cuts off power automatically once the phone is charged to full.

Another pro tip related to charging point is that never use a cheap charger. By doing so, you will just be putting your phone at risk as cheap chargers do not provide stable voltage output.

Additional Steps To Stop The Phone From Heating Up During Charging

1. Charge At A Place Where Heat Dissipates
Don’t even think about keeping your phone ar charge on bed or under the pillow. That is just asking for trouble as such cushiony surfaces trap heat within minutes. Instead go for flat surfaces like table, bedside cabinet and floor.


2. Charge Your Phone Without Cover
Those thick casings that you use to protect your phone slow down cooling so try to put your phone at charge without any cover on it.

3. Always Prefer Non-Fast Charger
As fast charging heats up the phone quickly, therefore a non-fast charging process can be your best bet for overnight charging in particular.

4. Let Your Phone Be At Rest During Charge
When your phone is at charge, just don’t use it. For sure a call or messaging on Messenger or Whatsapp doesn’t matter much but not heavy graphics games at least.

Wrapping it up in a nutshell, charging phone overnight is only bad if you don’t upgrade your phone every year. The lifespan of your battery will slowly start to shrink and you would eventually end up at a repair shop for battery replacement. But steps above can save you from that day to not come soon.

More resources: Apple / Gizmodo.
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