Stop Believing These 5 Myths About Charging Your Phone

Almost every smartphone we know of uses a lithium-ion (Li-ion) battery, so it’s safe to say that this technology is ubiquitous. Yet this remains misunderstood. Having the right knowledge is essential and can even impact your safety, such as knowing the warning signs that a Li-ion battery is about to catch fire. Besides safety, you would want the battery life to last as long as possible since a smartphone is a daily driver. But with charging myths abound, you might inadvertently do things that shorten its lifespan because someone gave you false knowledge about what constitutes good charging habits.

The lifespan of a lithium-ion battery is affected by several factors, including temperature, age, and charging habits. When it comes to charging, in particular, it helps to know when to charge, how to do it correctly, and for how long. This leaves several questions. For example, can you leave your phone charging overnight? Can you use any type of charger (as long as it works)? Are wireless chargers bad for the battery? Questions like these have given rise to widespread myths that can easily be dispelled.

Using your phone while it’s charging seems like a reckless thing to do since you’re simultaneously charging while draining the battery. It’s not unreasonable to believe that this could damage the battery, but that’s not always the case. Yes, charging may be slower because the phone will split the energy between charging and discharging, but unless you notice it generating a lot of heat, the battery will be fine.

Even though you can use it, it matters a lot what you do. You can do some low-intensity tasks because they generally don’t require the phone to devote a lot of processing power to them. These include checking email, reading an e-book, listening to music, writing notes, scrolling social media, or browsing the internet. It’s these high-intensity tasks, like playing mobile games, streaming 4K video, or recording video, that you should avoid because they generate a lot of heat (on top of the heat already coming from the charging process).

Heat can accelerate the rate of thermal degradation within the Li-ion battery, leading to loss of capacity or damage to its internal structure reducing its lifespan. The best thing to do when your phone is charging is to leave it alone, especially if you need it to get as much juice as possible quickly.

Sure, a $5 charger works because it basically does the job it’s supposed to do, but it’s one of those cheap phone accessories that you shouldn’t waste money on. The way these chargers could be detrimental not only to the phone’s battery but also to the overall health and functionality of the phone. The saying that you get what you pay for is generally true, as cheap, off-brand chargers are usually made from low-quality materials, which poses several problems.

Due to their low cost, these chargers do not regulate voltage properly, resulting in fluctuations above or below the recommended voltage. Too much or too little voltage puts strain on the battery and can cause the battery to overheat and deteriorate more quickly. On top of that, they can wear out your charging port, fry something inside your phone, or even short out the motherboard. This is why experts recommend using only certified brand chargers, especially when it comes to fast chargers, as they generate more heat when delivering high current.

While it’s recommended to stick with original chargers, if you have to buy one elsewhere, make sure they won’t damage your phone. For example, when purchasing a fast charger for an iPhone, make sure it is MFi certified. This means that Apple has approved it for both iPhones and iPads. For Android phones, look for a USB-IF certified charger. This certification means it has undergone rigorous testing to ensure it can safely deliver power to your device.

If your phone’s battery is protected against overcharges, excessive discharge remains a real danger for its lifespan. Its internal components are not designed to handle full discharges. For example, as the battery level approaches zero, the voltage becomes unstable, falling below the recommended threshold of 2.5 volts. When fully discharged, the battery has difficulty reaching normal charging voltage, which can put strain on its internal components. Overcharging or discharging can also cause the battery’s electrodes to oxidize (lose electrons), reducing their ability to hold a charge.

To avoid stressing the battery in any case, it is best to keep charge levels between 20% and 80%. This is called the 20-80 rule, and it avoids problems that shorten a battery’s life, including thermal and chemical degradation, as well as voltage instability. Also, don’t feel the need to always charge the battery to 80% once you start. You can stop at 40%, 50%, 60% or 70%.

However, 50% is the recommended charge level, as this is when the battery reaches internal balance. But that doesn’t mean you should never discharge your battery. This is sometimes necessary when you want to recalibrate it. For example, this can be useful when you want to readjust the battery’s sensors after noticing that it is showing inaccurate readings (for example, one minute it is at 49%, then at 55% the next minute).

When you know the next day will be busy and you won’t have a chance to charge your phone, it makes sense to leave it charging overnight, especially if it’s low. Then you remember that you were told not to do it because it would cause overloading and overheating. While this was true for older Li-ion batteries, newer ones have mechanisms that prevent them from charging once they reach 100%, meaning they don’t overcharge. Instead, the phone detects when the battery percentage drops a bit and then provides it with enough charge to keep it at 100%.

If anything can impact your phone’s battery life, it constantly keeps it at 100%. This puts a strain on the battery, but modern Li-ion batteries are designed to handle this. Even so, it is possible to leave it charging overnight occasionally, but not every night. Fortunately, some modern phones have features that delay charging to 100%, such as optimized battery charging on iPhones and “battery protection” on modern Samsung phones. Be sure to enable these features if you frequently charge overnight.

To avoid excessive heat buildup, it’s best to keep a few best practices in mind. Do not place it in a poorly ventilated area while charging, such as under the pillow, in your drawer, or between books. Also use high-quality chargers and remember to remove the phone from its case, especially if it is thick.

It’s important to mention that if you’re going to charge your phone overnight, it’s best to use a wired charger. You can place your phone on a wireless charger because it’s very convenient and go to bed without thinking much about it. However, wireless chargers are not efficient, causing them to generate a lot of heat. Heat will age the battery, but if it overheats, things can get dangerous.

A wireless charger transfers energy through the air, but not all of it reaches the battery due to conversion loss. Even wired chargers experience conversion loss to some extent, but not as much as wireless chargers. For this reason, wireless chargers are generally slower and constantly generate heat. If the charger is not perfectly aligned with the phone’s charging coil, the process becomes more inefficient and generates a greater amount of heat. However, Qi2, the latest wireless charging protocol, allows for faster charging speeds and efficiency. A Qi2 brand charger also has magnetic alignment, which snaps it onto a compatible phone, aligning it perfectly with the charging coil.

As with overnight charging, use it only when necessary. Additionally, it is important to ensure that your phone stays cool when using a wireless charger by placing it on a hard surface in a cool environment and removing any thick case. Also follow the 20-80% rule, avoid using it while charging, and use a high-quality wireless charger.