Cell Phone Charging 101

Tech - by Joe Weber - updated on 3/29/2024

Cell phones and smartphones are quickly becoming some of the most costly devices that we need and use daily. Knowing how to properly charge your phone is key to ensuring its battery lasts a long time and avoiding having to spend all that money for a new phone sooner than necessary. Keep reading to find out some of the best tips to ensure your phone battery has a long and healthy life.

Is It True That You Should Never Charge Your Phone to 100%?

It sounds strange but correct, even though this is something that we all do. We leave our phones on the charger until the battery is charged to 100%. Is charging to 100% harming the battery? According to Asidor Buchmann  , CEO and founder of Cadex Electronics and the founder of Battery University, charging your phone to a complete 100% charge is not ideal for the battery. Lithium batteries found in today's rechargeable phones do not like to be fully charged, especially when it's warm out and the battery can get hot.

What Is The Ideal Charging Percentage?

In a perfect world, you would never let your phone drop below 20% or charge higher than 80% for the best battery life. That's easy, right? No. For someone who lives on their phone a lot it can be quite tricky, I've gone below 20% at least three times this week. That's where low-power mode comes in handy.

Keeping your battery between 20% and 80% is not the easiest thing to do with smaller batteries like the one in your phone. While not easy for some, by following the charging tips we've laid out below you should still be able to keep your phone's battery happy and healthy for a long time.

Should I Charge My Phone Overnight?

Something that most of us do is plug our phone in when we go to bed and unplug it in the morning when we wake up. It will be a surprise to many people that this too can be harmful to your phone's battery when done frequently.

As we learned earlier, the sweet spot is between 20-80% so unless you miraculously wake up when the phone hits 80% it's better to charge your phone during the day when you can keep an eye on your charge level as it's charging.

If you, like most people. charge your phone overnight, we recommend turning on Optimized Battery Charging if your device has the option. If your phone doesn't have that feature, when the battery reaches 100% it stops charging, and then as soon as the device drops to 99% it charges back to 100%. This constant charging, non-charging cycle can be damaging to your battery over time.

What Is Optimized Battery Charging?

Apple developed a tool that is now built into all new iPhones, iPads and even new Macs to aid in the preservation of battery life and even extending it. This feature is completely automatic and is now enabled by default on new Apple devices.

Turning this feature off or on (though I don't know why you'd want to turn it off) is just a few taps away.

To turn on or off:

1. Tap Settings
2. Tap Battery
3. Tap Battery Health & Charging
4. Toggle the switch for Optimized Battery Charging

With Optimized Battery Charging turned on, your phone will use artificial intelligence to learn your daily charging routine and delay charging past 80% until shortly before you need to use the battery. This prevents the battery from being at 100% for long periods which can be harmful to the battery in the long run.

Is It Bad to Let My Phone Die?

A common misconception is that you should allow your phone battery to completely die before recharging. Don't do this. Modern lithium batteries used in phones today will wear out much faster if you constantly drain the battery to 0%, or let it die, before recharging.

The best thing you can do for your phone is what's called a partial discharge. Don't let your phone die, instead plug into a charger before it displays the prompt to turn on "low power mode", ideally around 30-40%, then unplug at around 90% to increase its lifespan.

Is It Safe to Charge My Phone Multiple Times Throughout the Day?

Yes. Lithium-ion batteries like to be charged in short spurts. If you work in an office and are up moving to meetings throughout the day, plugging your phone in for 20 minutes here and 10 minutes there may be beneficial for the health of your battery.

Now, if you need to charge your phone multiple times a day just to get through the day, then it may be time to stop into Batteries Plus for a free check-up and possibly a quick and inexpensive battery replacement.

Do "Fast Chargers" Damage Batteries?

Chances are you've seen the words "fast charge capable" if you've purchased a new smartphone in recent years. Fast (or quick) charge capability means that the phone can safely use a compatible high-capacity wall or car adapter to reach higher charge levels faster than a traditional charger.

You might think that pumping higher amounts of energy into the battery will damage it but, no, using fast chargers on phones that are built to support them is perfectly safe and will not harm your phone's battery.

What About Wireless Chargers?

Wireless chargers are a fantastic charging tool. Most new phones come with wireless charging capabilities and they are so easy to use! No fumbling with cords or having to plug anything in. Just set your phone on the charging pad and off you go. Wireless charging doesn't inherently harm your battery but wireless chargers do generate more heat than a traditional charger, which can be detrimental in the long run.

It is completely normal for your phone to get warm when using a wireless charger but it should never be hot to the touch. If your phone is hot, this could be that the phone is not placed on the charger correctly, or worst case scenario, a problem with the battery itself.

How Do I Check the Health of My Battery?

Keeping an eye on your battery's health is quick and easy. Most smartphone brands have built-in battery health monitors in their phone's software. They are pretty easy to find but they are slightly hidden in the device settings menu.

Here are the steps to check your phone battery's health on the two major brands out there.

Apple

1. Tap Settings
2. Scroll down and tap Battery
   This screen will show you the charge pattern, battery level history and the activity on the phone that uses the battery.
3. Tap Battery Charging & Health
   This screen will show you the maximum capacity your battery currently has which will get lower as your battery ages, so don't be surprised if it's not at 100%. If your battery is displaying a warning and your maximum capacity is lower than 80%, it would be wise to reach out to the experts at Batteries Plus for a replacement battery. This screen is also where you find the toggles to turn on and off Optimized Battery Charging.

Samsung

1. Go to Settings
2. Tap Battery and Device Care
3. Tap Diagnostics
4. Then Battery Status

This screen will provide details on the life of the battery (ie. Good), the capacity of the battery and whether or not the battery may need to be replaced.

Other Android Phones

You can download third-party apps through the Google Play Store that can provide details of the battery's health or on many Android phones you can dial *#*#4636#*#* from the phone screen to see detailed information about your battery.

What Charging Accessories Should I Have?

Having some helpful charging accessories on hand will make charging your phones and tablets easier.

• Extra Chargers - Especially helpful if you work from home and would like to charge your phone in your office without having to move your charger around.
• Car Chargers - Most vehicles come with USB ports now so a DC car charger is not as common as it used to be. Still, for those without USB ports, these chargers give your phone the life it needs when you're on the go.
• Wireless Chargers - Convenient and easy to use, these are great for those looking for an easy, place your phone and go charging solution.
• Power Banks - Always a great option if you're out and about and need a quick boost. Just plug in your phone and keep going. Usually small enough to fit in a backpack or purse for easy transport.
• Goal Zero Power Stations - For those who want to be prepared for anything, the Goal Zero power stations provide plenty of power to charge up your devices when the power goes out at home or while camping in the woods.
• MagSafe (Apple) - If you own a new iPhone that features MagSafe (iPhone 12 and newer) then there is nothing better than snapping the charger onto your phone and never worrying if it's placed right. Just set your phone and it uses magnets to keep it correctly aligned on the charger until you take it off.

Tips to Extend Battery Life

• Avoid "Parasite Loads"
  Try not to use your phone while it is charging. Doing so can confuse the battery by creating "mini-cycles" which will speed up the aging process of the battery.
• Close Unused Apps
  Closing out of apps that you are not using will help reduce the amount of battery that your phone consumes during the day by reducing the resources required to keep all of those apps open in the background.
• Limit the Amount of Time Plugged in at 100%
  If you have the option, use Optimized Battery Charging to avoid continuous charging after the phone reaches a full charge. If you don't have that option, consider charging the phone during the day when you can monitor the charging.
• Stay in the 20-80% Charge Range
  For the long-term health of the battery try to keep the phone in the sweet-spot range of 20-80%.
• Keep the Phone Cool
  Excessive heat damages batteries. Remove the case from your phone when you plug it into a charger and try to avoid using the phone in extreme heat. The optimal ambient temperature range for batteries is between 32℉ and 95℉.
• Use Battery Saving Features
  When you get that pop-up to turn on low power mode, power saving mode or whatever it may be called on your phone, use it! This will turn off unnecessary features to save energy and squeeze out more time. Don't be afraid to use this before your phone gets down to 20%.

Can I Replace the Battery Myself?

While it may sound tempting to just do the battery replacement yourself to save some money, there are a lot of tiny screws, and easily breakable components. The repair procedure requires strict attention to detail and care, not to mention the questionable quality of parts sold through some online resellers. No one wants this stress. This repair should be left to the experts at Batteries Plus.

Should I Replace My Battery or Buy a New Phone?

New phones can cost anywhere from a few hundred dollars to well over $1500 depending on which model and storage capacity you choose. That's a pretty hefty amount to spend out of the blue when your battery starts to wear down.

Having your battery replaced by the certified technicians at Batteries Plus is quick, most battery replacements take less than an hour, are inexpensive, convenient, and all of our repairs come with a nationwide 6-month warranty in the unlikely event that something happens after your repair.

Walk out the door with your phone working like new and saving hundreds or even thousands versus buying a new phone. Visit us online to schedule your repair or stop into one of our local Batteries Plus stores to see how we can help you.

Learn why having your repair done at Batteries Plus is a smart choice in "Why You Should Have Your Phone Repaired at Batteries Plus" and why our repair technicians are some of the best in the industry by reading "What is WISE Certification and What Does It Mean for Cell Phone Repair?".