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Safe Ways to Charge Your Smartphone’s Battery

Safe Ways to Charge Your Smartphone's Battery

There’s a lot of discussion about the best (and worst) ways to charge your smartphone. Is it harmful to leave your phone charging overnight? Should you never charge your phone above 50 percent? What are the best practices to make sure your phone battery has a long life?

It can get overwhelming, particularly when articles contradict each other. How do you determine what the correct information is? Are there charging habits that put your smartphone or battery at risk? Or, is it as simple as connecting your smartphone to your charger and not stressing?

For the most part, there’s no need to stress about charging your smartphone. Smartphone technology and batteries continue to improve with time.  As technology advances, some of the warnings about harmful smartphone charging habits no longer apply, and this can lead to confusion. 

That said, there are some habits you want to avoid when charging your smartphone. By incorporating a few good smartphone charging habits, you can charge your smartphone with confidence. 

Please see some of our other articles, “What is Sustainability on an Eco-Friendly Smartphone?” and “Smartphones Exciting Future: 5G, Hardware, AI, Gaming, & Apps.”

Five Do’s and Don’ts Of Charging Your Smartphone

1. Charging your smartphone overnight won’t overcharge your battery, but there are other reasons to avoid charging all night (or day) long.

Whether or not charging your smartphone overnight hurts your device’s battery is one of the questions that gets asked most often. Unfortunately, the answer to this question varies among articles. That said, it’s likely because the answer takes a little explaining.

For older smartphones, there was a real concern that leaving your device on a charger for long periods could cause the battery to overcharge, and therefore, reduce the battery’s lifespan. 

Fortunately, experts seem to agree that lithium-ion batteries, like those used in newer smartphones, do not overcharge. First, once a lithium-ion battery reaches its full charge, it stops charging. Additionally, more modern smartphones are designed to prevent overcharging from happening. 

That said, allowing your phone to sit on the charger once it’s fully charged can lead to your phone continually trickling new energy into your phone every time the battery drops to 99 percent. This constant trickle charging of your smartphone’s battery can have negative consequences such as:

  • Reducing your battery’s overall lifespan due to increased chance of metallic lithium forming in your battery also referred to as lithium plating
  • Causing your smartphone to heat up too much. Your battery gets warm when it’s charging, so allowing it to charge for long periods can cause heat to build up. 

Recommendation: Avoid leaving your phone on a charger once it has fully charged. However, if you do leave it on the charger for long periods, don’t stress. In general, this is unlikely to cause a major problem.

What should you do to avoid problems if you need to leave your smartphone charging overnight or during the day for long periods?

If you need to leave your phone charging for long periods, try incorporating some of these strategies to minimize the risk of your phone overheating or to avoid your battery from trickle charging.

  • Turn your phone off when you’re planning to put your device on a charger for an extended period. This strategy will help you avoid your battery trickling in new energy since the battery won’t drop charge while it is turned off.
  • To avoid the potential for overheating, take your phone’s protective case off while charging.
  • Plug your smartphone into a smart plug that’s programmed to turn off after a certain amount of time.

2. Avoid Using Public USB Charging Ports When Possible.

A young woman sitting at a charging station and looking at her smartphone. Recharging mobile phones from free charge station at the airport.

When you’re traveling, it’s easy to run low—sometimes critically low—on power. Seeing a public USB charging port can seem like a lifeline in those situations. However, experts warn you to proceed with caution—these public charging ports can potentially give you more than power.

The risk is that the USB connection that you use to charge your phone can also be used to transmit data. The concern is that a hacker could use the USB ports to transmit viruses to your phone. 

The truth is that, yes, a virus or other program could be uploaded onto your phone while you’re using a public charging station, and you would not know it was happening. 

Additionally, hackers could access your data through the USB port connection.

That said, newer phones have some protections against this possibility. Both iPhone and Android typically ask for your permission before sharing data or information. On an Android phone, you’d have to enable transferring files over that connection; your iPhone will prompt you to “Trust This Computer” when you’ve plugged into a device that is trying to gain access to your phone. If you don’t give these permissions, then your phone will charge but won’t accept the data.

Additionally, do not use a cable that you don’t own or trust. Hackers can use the cable to access your data files or upload a virus. 

Recommendation: Avoid using public USB chargers or cables when possible. 

That said, here are three ways you can charge while on the go, including two options that allow you to use a public USB charging station safely.

  • 1. If you travel a lot, consider carrying a portable charger with you.
  • A portable charger or power bank allows you to charge your phone anywhere without the need for an electrical outlet or USB charging station. 
  • 2. Another option when traveling is to bring your smartphone’s adapter and cable with you.
  • You can safely plug into any electrical outlet instead of using the public charging port. There is no risk of having a virus transmitted to your device or someone hacking into your phone if you’re using an electrical outlet with your cable and adapter.
  • 3. If the public charging station offers a standard electrical outlet, you can safely plug your phone into the electrical outlet using your adapter and cable.
  • Some charging stations have electrical outlets for charging your phone. Even though those outlets are attached to the public charging station, you can use the electrical outlet with your charger without any concerns.
  • 4. You can use a USB-only charge adapter safely at public charging stations.
  • If you need to rely on public charging stations, you can buy a USB-only charge adapter to charge up safely. You plug the USB-only charge adapter directly into the USB port of the charging station. Then you connect your smartphone’s charging cable into the adapter. The data pins in the adapter are disabled. Therefore, all it can do is allow power through and not transmit data. 

3. Don’t Let Your Phone Battery Run Out Before Charging.

In general, it’s better to charge up your smartphone before it requests to go into a low power mode, and definitely before it loses all of its charge. Lithium-ion batteries wear out faster if they are repeatedly allowed to go down to zero percent. 

Overall, keeping your battery charged between 50 to 80 percent seems to be an optimal range for lithium-ion batteries. This doesn’t mean you should never fully charge your phone or that anything bad will happen if it occasionally goes lower. However, you ideally should not let your phone drop below 20 percent too often. 

Recommendation: Ideally, charge your battery before your smartphone requests to go into low power mode. Lithium-ion batteries work best when they receive partial charges, so don’t be afraid to charge your lithium-ion battery. 

4. Make Sure Your Phone Isn’t Too Hot When Charging.

It’s normal for your smartphone to get warm when charging, especially the back of your phone or case. However, your phone shouldn’t get too hot—such as very hot to the touch—while charging. If the back of your phone is too hot while charging, the problem may be a battery that’s overheating. 

That said, there can be other reasons your phone is heating up. If you’re using your phone while charging, this could cause your phone to run warmer than usual, especially if you are gaming, streaming, or using an app that heats up your phone. Please note, however, that you typically can use your phone while it’s charging. This should not cause any problems overall.

If your phone is overheating, do not put it into the refrigerator or freezer. Your phone and its battery do not function well under extreme temperatures, and it can cause damage to your phone.

Recommendation: If your phone is getting too hot while it’s charging, unplug your phone and let it cool down. 

Follow these tips to help your phone cool down faster if it’s gotten too hot.

  • Close any apps that are running. You may want to take note of which apps were running on your phone in case it was an app that was causing your phone to overheat. Some apps can use a lot of your battery. If that seems to be the problem, you may want to avoid that app and use that application over the internet if possible instead. 
  • Remove your phone’s case to allow the heat to escape faster.
  • Put your phone into airplane mode, low power mode, or turn it off until it is cooler.
  • Dim your screen’s brightness.
  • Disable Bluetooth and GPS to give your battery less to manage until it cools off.

5. If Storing Your Phone (Or an Old Phone), Have the Battery About Half Charged.

If you’re not planning to use your phone for a while or are storing your old phone, the battery will do best if you store it at about 50 percent. Additionally, try to store your smartphone someplace where the temperature remains around room temperature.

Recommendation: If you’re not planning to use your phone (or a tablet) for a prolonged period, have the battery about half charged. However, if you store your phone at a full charge, don’t panic. It likely will be fine.

Taking a Few Simple Precautions When Charging Your Smartphone Can Help Prolong Your Battery’s Life

Questions and concerns abound about how to charge a smartphone correctly. In general, you can charge your phone without too much thought. Most phone batteries are going to last around two years or so. If you tend to upgrade every few years, then your phone’s battery likely will last, even if you occasionally discharge it fully.

That said, it is important to pay attention to your phone’s temperature and to try and avoid using your device in extreme temperatures (or leaving it sitting in the sun or on a hot car dashboard). Also, charging your phone with approved chargers and minimizing the risk of viruses from charging ports can help ensure your device and its battery lasts.


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We are a website that writes helpful articles about the latest technology for emergency preparedness and power grid energy. We try new devices and analyze their quality, durability, effects, for emergency preparedness.

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We are a website that writes helpful articles about the latest technology for emergency preparedness and power grid energy. We try new devices and analyze their quality, durability, effects, for emergency preparedness.

This site is owned and operated by Fremontii, LLC. Fremontii, LLC. is a participant in Amazon Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to