Should You Charge Your Phone to 100%?

can the battery be charged 100%

Updated: November 10, 2023

Battery degradation is inevitable. Even if you don’t do anything to the power source, it will gradually wear off. However, certain factors can speed this process up when you use it. This means that you can influence the life cycle of your battery by modifying your behavior.

There are many battery types. The rules to follow to prolong the power source life cycle will mostly depend on what is right, for one can be bad for another. As a result, various charging myths spreading on the internet can deteriorate battery performance should you put them into practice regularly.

You will hardly notice any difference if you buy the smartphone to resell it in a few months. However, if you use it for two-three years, degradation can be pronounced. Let’s have a look at the best practices to follow to prolong your battery lifespan.

When should you charge your phone?

A smartphone is designed to serve for one-two years. After this period, you will probably buy yourself a new one too:

  • get a new technology that wasn’t available at the time of purchase,
  • be able to use new Android or iOS version,
  • enjoy new, up-to-date hardware – cameras, processor, etc.,
  • have a better-looking device.

If you have a new phone every year – there is no reason to bother about charging behaviors. You will hardly notice any difference in a lithium-ion battery (most commonly used type nowadays) in the short term, continue doing your thing. There is one main advice for the rest of the people – avoid charging for extended periods (for example, overnight). Long cycles speed the degradation process up, use shorter ones instead.

The cycles and their duration will depend on your daily routine. Find long enough gaps during which you have access to the outlet. For example, you can charge in the morning after waking up before going to work.

How often should you charge your phone?

Have you heard the term “memory” regarding the phone battery? If you use a lithium-ion power source, you can forget about it. This means that you can charge it whenever you want – at 20, 60, or 80 percent, and you will never notice any capacity loss connected to this. Smartphone manufacturers have various technical ways to avoid overcharging so that you do not have to worry about this factor.

Feel free to top the battery up as often as you want. However, you should not:

  • discharge up to zero percent,
  • charge up to 100%.

When you store a phone or a battery, charge it up to half of the capacity and keep this way to avoid premature aging. This leads us to the conclusion that we should not leave fully charged battery for long.

What you should never do

Certain things sufficiently shorten battery life. To avoid deteriorating it prematurely, don’t:

  1. Leave it somewhere very cold or hot. Keep in mind that heat is the worst battery enemy – don’t charge (or leave) it in your car on a sunny day.
  2. Use fast charge for long as it generates excessive heat. Always take off the covers – especially the thick ones.
  3. Completely discharge or fully top up.
  4. Use smartphone much when it fuels up. Power it off if you can. Looking notifications or moderate browsing is fine.

Smartphones were created to make our lives easier, not harder. There is no reason to bother much about the charging rules since you will probably never use the same device for over two years. New technologies emerge very fast and are quite often used for marketing purposes. The manufacturer will rarely update OS for old devices to make you buy a new one. If you still wish to prevent your battery from aging, follow simple rules described in this article. This way, you will make sure you are making most of your battery.

Charging your phone’s battery to 100% from a low 25% — or pretty much any amount — can reduce its capacity and shorten its lifespan.

According to Battery University, lithium-ion batteries do “not need to be fully charged, nor is it desirable to do so.”

“In fact, it is better not to fully charge,” it says, “because a high voltage stresses the battery” and wears it out in the long run.



Is it bad to charge your phone to 100?

Rather no, then yes. However, it is not advisable.

Is the 40 80 battery rule real?

Yes, it is. Technically, this is a recommendation for the operation of the battery.

How many cycles does a cell phone battery last?

Usually manufacturers specify a number in the range of 400-1000 cycles.

Is overnight charging bad?

More likely yes than no, as it is not recommended to continue charging after a full charge has been reached.

What happens when phone is charged overnight?

The battery is constantly being recharged, which accelerates battery degradation.

Is it bad to charge your phone on low power mode?

It is not recommended that the battery charge level go below 15%

How do I keep my battery at 100 %?

No way. The battery degrades annually by 3-7% even if not in use. To extend battery life, it is advisable to charge the battery between 20-90% at room temperature. Also, do not allow the battery to overheat.

How many hours should a phone be charged?

It depends on your phone, charger and phone battery. We recommend reading your phone’s manual or you can measure the time it takes to charge your phone from 0 to 100%.

Should I only charge my phone to 80?

It’s advisable because this will extend the life of the battery.

How can I increase my phone battery life?

You can follow these tips:
Charge the battery at room temperature.
Do not overheat or operate at sub-zero temperatures.
Charge the battery within a range of 20-90%.
Do not use fast charging technology.

Is it okay to charge you a phone several times a day?


Is it bad to unplug your phone before it reaches 100?

No, it isn’t.

Can I leave my iPhone 12 charging overnight?

It’s not advisable.

How do I keep my iPhone battery healthy?

The same tips we gave above:
Charge the battery at room temperature.
Do not overheat or operate at sub-zero temperatures.
Charge the battery within a range of 20-90%.
Do not use fast charging technology.


Thanks to the built-in phone protection mechanisms, charging automatically stops if the battery is charged to 100%. This is not harmful to the phone, but there is some risk. You can charge your phone up to 100%, but it’s not desirable. In most cases, it is recommended that you charge the battery to 80-90%.

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About the author

Alex Gustman

My name is Alexander.
I am the author of articles, reviews and videos on the YouTube channel of I have been testing various electronic devices, mobile games and Android applications since 2012.

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  • Hmmm, I’ve been charging my Moto Z Play at night and always to 100%. It’s 5 years old and the battery still lasts two and a half days on one charge. Great phone, I guess!

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