Guide: How to choose which fast charger to buy for your smartphone

Not all fast chargers are created equal. In this practical guide, you'll learn how to choose the right one for your phone.

Guide: How to choose which fast charger to buy for your smartphone

First off, this article will not address the addictive rationale behind needing a fast charger, but the bummer moment as to when you anticipate a lightning-fast charge to get back to your normal daily consumption, only to find your battery at 46% after 2 hours. Disappointing, right? 

Like many Android smartphone users you might have invested in a fast charger with a different capacity from your device, or you might not be using the optimal charging technology for your phone.

So how do you know which fast charger is the best fit for your high-end phone? 

We have provided tips in this guide to help you.

How fast chargers work

A fast charger is a type of power adapter designed to significantly shorten the charging time of a compatible electronic device, compared to standard chargers. They work by delivering higher power levels, typically measured in watts, to the device's battery. While there's no universal standard, fast charging generally entails power delivery exceeding 5 watts (equivalent to 5 volts and 1 ampere).

Smartphones nowadays incorporate intelligent charging technology, adjusting power intake based on battery status and temperature. Even budget phones now feature faster-charging batteries to meet user demands for longer battery life and shorter charging times. 

Premium devices like the Samsung Galaxy S20 and iPhone 11 are equipped with high-power chargers that can deliver fast charging. However, it's essential to verify the accuracy of manufacturers' claims before purchasing a charger. Always conduct thorough research to ensure compatibility and safety.

What to consider before buying a fast charger

To identify a quality fast charger for your smartphone, consider the following tips:

Find out how much power your phone can handle in watts (W) 

The first thing you need to know is how much power your phone can handle in watts (W). This is usually listed on the phone’s specification sheet or manual. For example, the Samsung Galaxy S21 Ultra can support up to 25W of charging power. 

Keep in mind that the more power your phone can handle, the faster it can charge. However, this also depends on the charger’s power output. If the charger’s power output is lower than your phone’s power requirement, your phone will charge slower. 

If the charger’s power output is higher than your phone’s power requirement, your phone will only draw as much power as it can handle. Therefore, you should look for a charger that matches or exceeds your phone’s power requirement.

Check what charging standard your phone supports 

The second thing you need to check is what charging standard your phone supports. This is the protocol that determines how the charger and the phone communicate and negotiate the optimal charging speed. 

Some phones use proprietary standards, such as OnePlus’ Warp Charge or Oppo’s SuperVOOC, which require you to buy a branded charger and cable. Other phones use universal standards, such as USB Power Delivery (PD) or Qualcomm Quick Charge, which are compatible with many third-party chargers and cables. 

You should choose a charger that supports the same charging standard as your phone, or a universal standard that is compatible with your phone.

iPhone and Google-Pixel 6 Charging Spec Sheet
“USB-C chargers with power outputs of 18W or higher are usually capable of fast charging.”

Stick to reputable brands 

The third thing you should consider is the brand or manufacturer of the charger. Cheaper, low-quality chargers may not provide reliable and safe charging performance. They may overheat, damage your phone’s battery, or even cause a fire. 

Reputable brands like Samsung’s 45W and Oraimo’s PE2.0 often undergo rigorous quality testing to meet compatibility and safety standards. They also offer warranties and customer service in case of any issues. You should buy chargers from reputable brands or manufacturers that you trust.

Read product reviews 

The fourth thing you should do is read product reviews and feedback about the charger you are considering. This will give you a better understanding of the charger’s performance and reliability. You can also learn from other users’ experiences and tips. You should look for positive reviews that confirm the charger’s fast charging capability, compatibility, safety and otherwise.

Multi-device charging

The fifth thing you should think about is whether you need to charge multiple devices from a single charger. If you do, check the number and type of ports on the charger, and how much power they can share. For example, if you have a 25W phone and a 45W laptop, you need a charger that can output at least 70W in total. You also need to check that each port supports the charging standard that your devices need. 

Some chargers have multiple ports with different standards, such as USB-A and USB-C. You should choose a charger that can accommodate all your devices and charge them efficiently.

Multiple port wall adapters | eBay

Test, Test, Test

Have you bought a charger and feel you are not getting the fastest speed? The only way to diagnose the charging power of your phone is through testing. You can use apps like Ampere or AccuBattery on Android to measure the charging speed and the battery level of your phone. You can also compare the charging time with different chargers and see which one is faster. You should test the charger in different scenarios, such as when your phone is on or off, when your phone is using data or Wi-Fi, and when your phone is hot or cold. You should also test the charger’s safety and durability by checking its temperature, cord, and plug.

Charging Readouts from Ampere and AccuBattery 

Fast Charging FAQs

Will fast charging damage my battery?
Damage is rare if everything's well-managed inside. A battery's management system closely monitors the two charge phases and drops the charging speed during the second phase to give the battery time to absorb the charge and avoid issues, which is why it can take 10 minutes to get those last few percentage points. 

What percentage is the best time to recharge my phone?
30%. If you want to take a more active hand in your battery's health, plug in your phone when its battery level gets down around 30%, well above the stressfully low battery levels.

Can I use mismatched chargers?
Unless you're using counterfeit or damaged chargers and cables, mixing and matching cables and chargers is not going to harm your battery. However, you may not be charging up as quickly as possible when you use the ones that came with your device. 

How can I conserve my battery power?
You can use the usual energy-saving tricks to conserve your battery's power, such as dimming your display's brightness, turning off Wi-Fi and Bluetooth when you're not using them, restricting background data usage through settings, and keeping an eye on apps that use GPS.

Do Android phones charge faster than iPhones?
Yes, Android phones charge faster compared to iPhones, even in the absence of the fast charging feature. A review has shown that within a 15-minute charging window, devices such as OnePlus surged to 20% battery capacity from 0%, whereas the iPhone only experienced a 9% increase.


Fast charging can mean the difference between running out of power while using your phone or staying fully charged in just 20-30 minutes. So, the question is, how compatible is my fast charger with my phone? Understanding these can help you make the right choice when buying.

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