Technology advances quickly, so it’s no wonder that you may have heard conflicting things about the proper care for your smartphone, tablet, or home computer. We hear all kinds of rumors from friends and family about leaving your phone plugged in all night or making sure to discharge the entire battery before recharging–but how can we know which information we should actually trust?
The reality is that most of these “tips and tricks” passed around for years are outdated, and in 2022, many of them are nothing but myths. Of course, these misconceptions were built on a thread of truth; they would not have become myths at all. Check out some of the most common smartphone myths below, and find out just how damaging your overnight charge truly is.
Myth: Charging your smartphone overnight will overload the battery.
Is it true? FALSE
Many people like to charge their smartphones overnight. After all, it’s a convenient time to charge, and everyone likes to have a full 100% at the start of the day. But is this overloading the battery? You may have been warned by a friend or colleague that you can “overcharge” your smartphone's battery by leaving the device plugged in for too long. What is “overcharging”? Is this really a thing?
In short, the answer is no. The latest smartphones are “smart” enough that they won’t charge beyond 100%. The device “knows” when it has a full battery and ceases charging, so you can’t “overload” it. You can, however, overheat it. Remember a few years ago when Samsungs were briefly known to catch fire? This happened because the phones were overheating.
Smartphones use lithium-ion batteries, which contain a flammable electrolyte. The devices naturally generate heat when they are on, and this heat can rise if the smartphone is left charging underneath something like a pillow, book, or bag. Though it is rare for smartphones to generate enough heat that they catch fire, it’s important to be aware that it can happen. Leaving your smartphone plugged in all night isn’t going to make it that hot… just make sure you never leave anything on top of it.
Now, it’s worth noting that leaving a lithium-ion battery plugged in for long periods does damage it, but not for the reasons you might think. More on this below.
Myth: Charging your phone or tablet overnight will damage the battery.
Is it true? TRUE
Like most batteries, the one in your smartphone comes with a limited lifespan from the start. If you have had a phone for more than a couple of years, you have probably noticed that the battery dies a lot faster than it used to. This is because lithium-ion batteries lose some capacity over long-term use. The problem with leaving your device plugged in overnight is that it will reduce battery capacity slightly faster. Here’s why:
Every lithium-ion battery only has so many charge cycles before its capacity starts to degrade–the batteries in most of the latest smartphones have about 500 cycles. A “cycle” refers to a full 100% charge, which doesn’t necessarily occur each time you charge your phone. For example, if you plug your phone in when it’s at 60%, that 40% charge is 40% of a cycle. Due to this system, you never have to worry about getting a “full” cycle. It will all add up in time.
But unless your phone is off, it will still use a small amount of power even when you aren’t using it. It needs a little juice to run its background operations. Now, if your phone is left plugged in, it will charge back up to 100% every time it drops below 100%, and this cycle will repeat until you unplug it. This small, continuous charge is commonly known as “trickle-charging.”
The “trickle-charge” may seem harmless, but it can waste your charge cycles and shorten your battery’s lifespan before it degrades. While it’s nice to wake up to a 100% charge, it may come at the cost of your battery’s longevity.
Myth: Extreme temperatures can damage a smartphone or tablet.
Is it true? TRUE
While people like to argue about how bad an idea it is to leave your smartphone plugged in all night, one thing we should all agree on is that extreme temperatures are bad! Whether it’s intensely hot or freezing cold, extreme temperatures compromise your device's performance and damage the lithium-ion battery.
If you have ever tried to use your phone in the blazing sun, you may have experienced reduced functionality due to the extreme heat. Your phone may slow down, disable the camera, or make other adjustments to regulate its temperature and keep things running smoothly. As we mentioned earlier, the lithium-ion batteries in your smartphones and tablets contain a flammable electrolyte that can catch fire if they overheat. This is why your device is programmed to make automatic adjustments when things start to heat up, and it’s also why we warned you earlier not to place anything on top of your charging phone. Even a small “trickle-charge” will generate some heat, and the device’s programming can only do so much to regulate temperature. It’s best to leave your phone or tablet to charge in a cool area with good airflow around the device.
While the cold isn’t quite as damaging as the heat, smartphone users should be aware that extremes are bad. Many people believe that freezing their device can reset their battery or improve functionality, but Battery University says that all they’re really doing is causing damage. If you charge a smartphone at sub-freezing temperatures, it can cause a permanent “plating of metallic lithium,” making the battery more prone to failure. If your smartphone is too hot to function properly, it’s best to leave it in a safe place and let the device cool down naturally.
Myth: You should always drain your phone battery to zero before charging.
Is it true? FALSE
This is a common myth that often accompanies the misconception that your phone battery has a “memory.” The memory effect means that if your phone is only partially discharged and you plug it in to charge, the battery will “remember” the charge it was plugged in at, thus shrinking the battery’s total capacity. This may have been true of the older NiMH phone batteries, but according to TechJury, the same issues simply don’t apply to the modern lithium-ion batteries in 2022.
As difficult as this may be to believe, lithium-ion batteries are actually under the most strain when they are either fully charged or completely empty. In fact, the battery will perform its best if you can keep it at a nice equilibrium of 20-80%. This sweet spot puts the least strain on the battery and actually increases the number of charge cycles it can withstand before it starts degrading.
Myth: Turning your smartphone off on occasion will help preserve battery life.
Is it true? FALSE
Modern smartphones and tablets are designed to be “always-on” devices, so it isn’t really important to power them down.
Some people suggest powering your smartphone off at night to preserve the battery, but Time says that won’t make much of a difference. These devices are not meant to be turned off regularly, so you should rarely see a need to turn your smartphone completely off.
If nothing else, turning off your smartphone or discharging the battery fully to 0% every once in a while may help calibrate the battery counter. If you find that your phone keeps dying even when it's above 0%, try turning it off and giving it a break for a little while.