Is fast charging bad for battery life?

Fast charging is becoming a standard feature on smartphones, electric vehicles, laptops and other gadgets. This is convenient as it allows you to charge your device or car in less time than you would normally have to wait.

But while fast charging is impressive, does it have any negative effects on battery life? And are fast chargers bad for your phone? Let’s break it down for you.

What is fast charging?

Quick Charge is a feature that allows you to charge your device in a fraction of the time it would usually take. Whether your phone or other device supports fast charging depends on the included charging circuitry.

Your device can only draw the power that the charging circuit was designed to handle. That’s why connecting your device to a fast-charging brick won’t necessarily make it charge faster. Of course, there can be other reasons why your smartphone is charging slowly, and you should take these into account as well.

Quick Charge makes it easy to top up your battery whenever you feel the need to recharge. With the increasing amount of time we spend on our devices and how difficult it is for a single charge to last all day, fast charging is more essential than ever.

We will use smartphones as an example in this article. On this front, there are several fast charging standards on the market. Fortunately, most are compatible with each other.


What is fast charging?

Fast charging has become an effective marketing term for different electronic products. However, you will often come across this term in smartphone marketing materials.

These materials can sometimes be misleading, tricking you into thinking your device supports fast charging, only to realize it doesn’t later. So how many watts is considered fast charging?

Smartphone manufacturers often label anything over 10 watts as a fast charge rate. However, there is no industry standard on what is considered fast charging speed. The higher the number, the faster the charging rate.

Will fast charging damage the battery?

This question usually arises due to the heat associated with bombarding your device with large amounts of energy. And as you may already know, heat is bad for your battery, especially lithium-ion batteries, which most smartphones use today. This is why fast charging systems strive to reduce heat as much as possible while increasing efficiency.

But does fast charging damage your device’s battery?

Not really. This is due to the fast charging. Fast charge batteries have two charging stages. The first phase is when they absorb as much power as possible. The first phase is usually when the battery capacity is low or empty.

This explains why, in smartphone marketing materials, you’ll see companies boasting that their fast charger takes a certain amount of time to charge the battery from zero to a certain capacity.

But once the battery’s capacity reaches that indicated level, charging speeds are reduced to avoid stress and heat that can adversely affect battery longevity. You’ve probably noticed that your phone charges faster to a certain percentage but takes longer to fill the battery; that is why.

It’s also worth keeping in mind that your phone may automatically disable fast charging if your device’s temperature rises above a certain level.

How are phone companies mitigating the impact of fast charging?

Smartphone makers have also come up with other ways to lessen the impact of the fast charging phase on the battery by using a dual-battery design. In this way, the two batteries share the high input charge during the fast charge phase, thus avoiding damage.

Another preventative measure is the various battery management software systems. Smartphones have a dedicated management system to supervise charging, preventing the battery from being damaged by high input charging. Apple’s Optimized Battery Charging is a prime example.

Essentially, the effectiveness of your phone’s battery management software determines whether or not fast charging harms your battery.

The bottom line is that fast charging won’t have a substantial impact on your battery life. But the physics behind the technology means you shouldn’t expect the battery to last any longer than using a conventional ‘trickle’ charging brick.

But that’s only one factor. The longevity of a battery varies depending on various factors. Apple support documentsfor example, say the following for his phones:

“A normal battery is designed to retain up to 80% of its original capacity at 500 full charge cycles when operated under normal conditions.”

In case you want to know, here’s how to check your iPhone’s battery cycle count.

Should you be worried about the effects of fast charging on your battery?

Not a lot. As stated above, the charging management system takes care of the battery to prevent damage. Clearly there is a chance that battery life will be affected, but it’s not to a substantial extent that warrants serious concern. So, you don’t have to worry too much.

Hopefully your doubts about fast charging are now cleared up.

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