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Should You Always Charge Your Phone to 100%? [Answered]

Should You Always Charge Your Phone to 100%? [Answered]

I always thought that since you have this option, you should always let your phone charge to 100%. But this is actually wrong and will do more harm especially in the long run. To help you keep your phone’s battery healthy, today we’re going to talk about the art of charging your phone!

Phone batteries don’t need to be charged to 100% to work properly. If you fully charge your phone’s battery, you will shorten its lifespan and also reduce its capacity. Ideally, you should only charge your phone’s battery to 80% and not let it get below 25%.

Charging your phone above 80% (and especially leaving it charge once it reaches 100%) will reduce both the capacity of the battery and also its lifespan. The same will happen if you let your battery percentage to go too low or fully discharge – the lifespan of your battery will be greatly reduced.

When your phone’s battery is about to reach maximum capacity, the high voltage resulting from that will put a lot of stress on it, wearing it down and reducing its capacity in the long term.

This is why our phones seem to last less and less on a full charge as time goes by: because we’re actually not supposed to do it at all!

Older phones were running on different technology and had nickel-cadmium batteries. Those had to go through a full cycle of discharge-recharge in order to work properly.

In other words, those older batteries were supposed to be allowed to get to 0%, then get a full charge to 100% in order to run in optimal conditions. But with modern, lithium-ion batteries, things are different.

But because many people started using mobile phones equipped with those old battery types, they still believe that full charging cycles and battery drains are recommended. Which is not true.

Why we should not charge your phone to 100%?

Modern phones are equipped with lithium-ion batteries, which are modern rechargeable batteries that have been constantly improved over the years.

charge your phone to 100

Despite the improvements, when you charge your phone’s battery to 100%, the resulting high voltage will result in additional stress of the said battery, reducing its lifespan and even its capacity.

This will take time, though, and not happen over night, but it’s clearly a practice that should be avoided.

Lithium-ion batteries like those installed on any phone nowadays will still lose capacity over time as they are not indestructible, even if you charge them correctly. But if you constantly charge to 100% (and leave your device charging at this point) can do even more harm.

How to correctly charge your phone?

As surprisingly as it might sound, the best option for you is to charge your phone to a maximum of 80%, but also never let it drop under 20%.

Lithium-ion batteries perform best when charged at around 65% to 75%. But since keeping the battery at these levels throughout the day is pretty much impossible, you should know that anything between 40% – 80% is also considered ok.

In order to correctly charge your phone, don’t let the battery run dry before plugging it in. Start recharging when the battery is above 20%, but don’t let the phone charge over 80%. You can charge your phone multiple times per day in order to achieve these numbers.

Now this shouldn’t be considered a rule set in stone. It’s rather a “best practice” type of thing. Your phone won’t be destroyed in two weeks if you don’t charge it as recommended above, but its lifespan might be reduced in the long term if it’s not charged correctly.

However, there are some voices claiming that modern phones are already optimized and taught to keep the battery in tip top shape even if you forget them plugged in.

For example, Business Insider had a chat with Ronald Ho, Google’s product manager, on how to correctly charge your phone’s battery.

He said that “given the current battery and charging optimizing technologies companies can build into their devices,” overcharging is not that big of an issue.

“When the phone’s battery reaches 100%, the phone’s internal battery charger will actually stop charging to prevent overcharging,” he added.

phone charging

And we did see some companies implement this indeed. For example, we have Apple’s Optimized Battery Charging Option for newer iPhones, which makes sure that you never overcharge your battery.

Even my ASUS laptop (which also runs on a lithium-ion battery) has a similar option that allows me to only charge it to 80% in order to improve battery life on the long term.

But unless you are certain that your phone does have these overcharging protections running for your battery, it’s best to play it safe and strive to always have your device correctly charged. This means keeping it anywhere between 40% and 80%.

What happens if you keep your phone charging after 100%?

You will not instantly kill your phone if you forget it plugged in and charging after it reaches 100%. But lithium-ion batteries are built in such a way that they don’t like being overcharged. When they are, they get worn down faster, resulting in a lower lifespan for the battery.

In other words, if you constantly charge your phone to 100% and let it charge afterwards, you can see a faster reduction in its battery life than if you would if you charged it properly.

Is overnight charging bad?

Yes, overnight charging is bad. Your phone will quickly reach 100% charging rate and then spend hours at maximum levels, with current still fed to the battery. This will do more harm faster, reducing the battery life faster.

At what percentage should I charge my phone?

charging smartphone

To keep your phone’s battery in perfect condition, you should start recharging it between the 40% and 80% ranges. Try not to charge it more than 80%. Also, don’t let the battery levels drop under 20%.

Lithium-ion batteries don’t like to be fully charged or fully drained. The only time when you should do a full cycle (let the battery discharge completely, then charge it to 100%) is when or if it starts behaving strangely – like shutting down when it says it still has 10% or anything like that.

But apart from that, keeping the phone battery between 40% and 80% is ideal. So try no never charge above 80%!

How often should you charge your phone to 100%?

Since phone batteries don’t do well when charged to 100%, if you only think about their well being, you should never fully charge them. But if you anticipate being away for a longer period of time, without access to a socket or electricity, you won’t kill your phone if you charge it to 100%.

Also, as mentioned above, if your device starts behaving strangely, running out of battery and shutting down automatically when it still shows 10% battery left, you should do a full cycle: charge it to 100%, then let it drain before recharging it fully. This is known as a battery reset, but in reality we rarely – if ever – need to do this.

Is it bad to charge your phone multiple times a day?

battery charging on phone

No, on the contrary! Lithium-ion batteries do best when you charge them in shorter bouts, even 5-10 minutes, multiple times per day. This prevents the battery from overheating, therefore prolonging its life.

So don’t hesitate to simply plug the phone in and let it charge for a while whenever you have the chance. Short rounds of charging will ensure that you have enough battery for your daily activities, keep the battery charged within the safe limits and help it last longer than otherwise.


It looks like there’s a lot to know about such a simple task as charging your phone, but fortunately you know everything about it.

The bottom line is that charging your phone to 100% – just like letting the battery drain completely – is not

recommended. But modern technology comes with built-in safety measures to prevent damage as much as possible even if you forget your phone plugged in overnight or for longer periods of time.

It’s still better to keep your phone between 40 and 80% for as long as possible since these are the ranges that li-ion batteries prefer, but even if you don’t manage to stick to these numbers, you will rarely – if ever – do irreversible and instant harm if you let the battery charge to 100%.

And now that you know all about batteries and charging, why not take a look at the best phones for Netflix and start your binge-watching adventure right away?