4 Common Battery Charging Myths You Should Stop Believing

In the age of smartphones, wearables, laptops and electric vehicles, our lives are heavily dependent on battery power. More specifically, lithium-ion batteries. Over the years, we have seen major advances in battery technology, including the emergence of new types of batteries thanks to advancements such as advances in sodium-ion battery research.

Despite this, many questions remain regarding batteries and how to get the most out of them. In fact, battery life has become one of the most important features to look for when buying a new phone, especially if you lead an active lifestyle and are often away from charging areas.

As with any basic piece of technology that we rely on every day, people have come to have preconceived ideas about batteries, how to use them, and what is best for them. While it’s certainly possible to charge your phone the wrong way and some of these ideas about batteries are based in truth – like that high temperatures can damage the battery – others seem more like myths that people continue to believe because they’ve always heard them.

This myth is originally based in truth, as it began to appear as an instruction for new electronic device owners back when nickel-cadmium (Ni-Cd) batteries were still the norm. The reason this myth continues to exist today is because of how deeply ingrained it has become among users of electronic devices, and there is a good explanation for this.

Previously used nickel-cadmium batteries suffered from what is known as a “memory effect”. This essentially meant that over time, recharging a Ni-Cd battery to a lower capacity could cause the battery to “remember” that capacity, making it the new amount of charge the battery could hold. A lot of this has to do with the way the chemicals in the battery’s contents crystallize over time. This meant that if you repeatedly used a Ni-Cd battery to 30% and then charged it to 75%, the battery chemistry would remember this as it would crystallize, resulting in reduced overall capacity.

Fortunately, this isn’t really a problem anymore, thanks to advances in lithium-ion batteries. Their chemistry is different from nickel-cadmium batteries, so their performance is not affected in the same way by these partial charge cycles. Because of this, you don’t have to worry about charging your new smartphone to 100% before using it, although it will certainly save you from having to rush to find a charger later.

Over the years, we’ve seen new features like charging limits, which help prevent your phone from charging beyond a certain threshold, usually something like 80% of the battery’s full charge. The reason these features have gained so much traction is that they are supposed to help limit wear and tear on your battery, as many believe that charging your phone to 100% will decrease the overall charging capacity.

This is another myth that seems to be related to old nickel-cadmium batteries of the past, as the memory effect could also come into play if you charge your battery to 100% too often. This was less of a problem if you completely discharged the battery, but it’s still a problem that appeared with these older types of batteries. Again, lithium ions have a completely different chemical composition, so this isn’t as much of a problem.

Yes, it is still considered bad to charge your phone to 100% and leave it on the charger, as this leads to what is called trickle charging, in which your phone slowly uses up power and then recharges it. This causes increased heat and stress on the battery in general, which can lead to additional wear and tear over time. That’s why we’ve seen features like Optimized Charging on iPhones, which determines the time you usually wake up and charges your phone the last 20% right before your alarms go off.

This is another myth that may be linked to the days of nickel-cadmium batteries. As we mentioned previously, the memory effect played a large role with these older batteries, so it is important to always fully discharge a battery and then fully recharge it to 100% to avoid having less capacity.

This is not the same with lithium-ion batteries like those found in smartphones and other electronic devices today. In fact, the opposite is true. Indeed, the biggest sign of battery wear is the reduction in its charging cycles, that is, when the battery capacity is completely exhausted. This is important because all batteries are rated with an expected number of charge cycles before the battery begins to degrade beyond its peak performance. The Galaxy S25 Ultra, for example, is rated for around 2,000 charge cycles, according to the European Product Register for energy labeling. However, these expected charge cycles do not mean that the battery will be useless afterwards, it just means that the capacity should drop to around 80%.

All of this explains why you shouldn’t fully discharge your battery before plugging it in, and that’s because each charge from 0% to 100% is a cycle. However, if you charge your phone from 20% to 80%, you’re essentially turning one charge cycle into two, because you’re not fully discharging it and then recharging it. This means that your battery capacity should ultimately last longer, as it will take you longer to run your intended cycles.

If you’ve ever read the instructions that came with your device, you may have noticed sentences that basically state that you should only use official chargers made by the device manufacturer. The reason is that, for example, if you are using a Google Pixel 10 and you only use the charger that Google offers, you are ensuring that your charger has the correct power specifications that the device is supposed to accept. This means you don’t have to worry about the charger providing too much voltage, as this could damage the battery.

However, the myth that you need to use an official charger is not entirely true. Although third-party chargers can be a waste of money and the official charger is inherently safer because it is already designed for your device, you can use other chargers. Using a third-party charger only requires a few extra steps to ensure you’re not setting yourself up to damage your battery in some way.

As mentioned, pay attention to the voltage supported by the device you’re charging and the charger you plan to use. Pushing too high a voltage into a battery that can’t handle it can cause internal damage. Additionally, the fast charging protocol used for charging is also important, if they are smart devices or those designed to be charged quickly. Different protocols will result in slower charging overall because the charger and device cannot communicate properly during power transfer. You may need to do some research to make sure these values ​​match, but once you do, you’ll have a much easier charging experience and ensure you’re charging your batteries safely.