Review: Anker PowerCore Essential 20000mAh

Anker PowerCore Essential 20000 mah main photo

Anker and its flagship power bank PowerCore Essential 20000. With over 18,000 ratings on Amazon, is one of the most popular and sold power banks on the market. Is it worth its price? Is it as good as reviews say? Read on to find out.

Anker PowerCore Essential 20000 mah additional photo Anker PowerCore Essential 20000 mah additional photo 2

Pros & Cons:


  • Supporting simultaneous USB charging by USB-A type ports

  • Superb material quality and design

  • Battery efficiency on 92%, one of the highest

  • It’s able to charge most mobile phones 4 times


  • Simultaneous charging and recharging is not supported

  • USB-C Input only; no cable provided, only Micro USB / USB-A

  • Doesn’t support laptop charging

  • It does not support fast charge output to phones only standard charge speed


Power & Performance (1 to 5 stars)

Design & Build (1 to 5 stars)

Technology (1 to 5 stars)

Overall Rating (average of above)

Key Specifications of a Product

Key Specs:

  • Capacity

  • 20,000 mAh / 72 Wh

  • Dimensions (LxWxH)

  • 6.2 x 2.9 x 0.8 in / 15.8 x 7.4 x 1.9 cm

  • Weight

  • 12 oz / 342 gm

Output & Input Charging:

  • Average Charging Time of a Mobile Phone (average battery capacity 3000mAh)

  • 1 hour and 20 minutes

  • Average Recharging Time (from 0% to 100%)

  • 11 hours


  • 2 x USB-A Output: 5V/3A

  • USB-C Input: 5V/2A

  • Micro USB Input: 5V/2A

Charging Technology

  • Fast-Charging via Leading Technology

  • PowerIQ Technology

  • VoltageBoost technology delivers an optimized charge to your devices

  • Trickle-charging mode - the best way to charge low-power accessories

  • Anker's MultiProtect safety system

Flight Status

  • Under 100WH

  • Safe to take on board.

Other Features

  • 18-Month Limited Warranty

  • Lifetime Technical Support

Ideal For?

  • Traveler

  • Student

  • Adventurer

What Inside?

  • Anker PowerCore Essential 20000

  • Protective pouch

  • USB-A to Micro USB cable

  • Manual in multiple languages

  • Welcome card

Power & Performance

Battery Capacity

Battery capacity in mAh, and Watts power.

The Anker PowerCore Essential has a battery capacity of 20,000 mAh / 72 Wh. This amount of energy is enough to charge most phones 3 or 4 times.

Capacity test - discharge the fully charged power bank

Have you ever wondered if the advertised power bank has the claimed battery capacity? Does it really have 5,000 mAh or 10,000 mAh as advertised? It’s possible to check it.

To check the actual battery capacity we need:

  • The fully charged power bank

  • A USB tester that shows the current, voltage, mAh, and charging time.

  • The USB mini adjustable load receives energy from the power bank and releases it safely via the fan. This is the safe way to discharge a fully charged power bank and measure the real battery capacity.

Let’s dive deep into the test and result. Following the aforementioned procedure, I tested Anker PowerCore Essential 20000 . Here are the results:

Capacity Test Powercore Essential 20000


What I found out:

  • Discharging Time - 6 hours and 54 minutes

  • Watt-Hours - 70.5 Wh

  • Ampere hour - 13644 mAh

The real battery capacity is 13644 mAh / 70.5 Wh. This amount of mAh precisely shows the energy that you will fully use to charge your mobile phone. If you are surprised why it’s not 20,000 mAh, that’s due to converting energy from 3.7V (power bank’s battery voltage) to 5V (USB’s voltage). This natural process occurs in every power bank.

Knowing advertised and the actual battery capacity it’s possible to measure the battery efficiency which is 92%. Manufacturers frequently don’t share this information. An efficiency above 90% is considered a very good one. Having said that, 92% is an excellent score, which proves a high-quality battery.

Disclaimer: Every test may vary, but only with a small variation.

How many times to charge the most sold mobile phones in 2020?

To put the battery capacity into perspective, I will use a formula for Real Battery Capacity and calculate how many times Anker PowerCore Essential 20000 mAh can charge the top 10 most popular mobile phones in 2020. Perhaps you own one of the enlisted phones or at least you know your mobile phone’s battery capacity. From the previous test, we know the real battery capacity which is 92%.

Once we know the real battery capacity, simply divide it by the enlisted mobile phones’ battery capacity to find out how many times it can be charged.

Mobile Phone Model

How Many Times Can It Be Charged?

iPhone 12 Pro - 2,815mAh


Oppo Find X2 Pro - 4,260mAh


Samsung Galaxy S20 Plus - 4,500mAh


OnePlus 8 Pro - 4,510mAh


Pixel 5 - 4,000mAh


iPhone SE 2 - 1,821mAh


Motorola Edge - 4,500mAh


Google Pixel 4a - 3,140mAh


Huawei P40 Pro Plus - 4,200mAh


Moto G8 - 5,000mAh


The tested device can easily charge almost all devices nearly 3 times. Moto G8 has the biggest battery amongst enlisted mobile phones and it can be charged over 2 and half times, nearer to 3 times, since most people don’t wait for their batteries to die completely. For smartphones with batteries around 3,000 mAh such as Google Pixel 4a, you can count on at least 4 full charges.

If you need a power source for 3 or 4 days for one phone, the Anker PowerCore Essential 20000 will be a great choice.

Output Charging

Charging Time & Power Usage

The main purpose of power banks is charging your devices, hence this review cannot be done without testing output charging. The knowledge of the charging time of devices is crucial. Frequently is one of the most important factors while purchasing a power bank.

For these tests, I used two mobile phones:

  • Huawei P10 with a battery of 3200 mAh (Huawei SuperCharge)

  • Samsung S8 with a battery of 3000mAh (Adaptive Fast Charging)

Both phones support fast-charging technology.

To record data (current, voltage, mAh, time) I used a USB tester.

Real-life examples, testing charging phones demonstrate what you can expect after purchasing the power bank.

The Anker PowerCore Essential 20000 is equipped with fast-charging technology via leading technology and PowerIW Technology. Having said that, the expectation bar is set high. Anker is already well-known for its cutting-edge technology. Let’s find out if the tested power bank will exceed a standard charging on level 5V/2A, but without USB-C PD for output charging it might be more difficult.

Test charging via USB-A (Huawei)

Test charging via USB-A (Huawei)

The tested power bank delivered the energy in standard time on level 5V/2A. The mobile phone was charged to almost 90% an hour and 11 minutes. Perhaps another 10 minutes could have added an extra 7% of the battery. It is a good time considering a standard output and quite an old phone without the newest charging technology.

Test charging via USB-A (Samsung)

Test charging via USB-A (Samsung)

Charging Samsung S8 wasn’t as quick as charging Huawei P10. It had almost the full blast to 97% and it took an hour and 35 minutes. The power bank delivered 2,159 mAh / 11.1 Wh of energy. It’s a decent score, but I had expected it could have been charged a bit faster.

Test charging via USB-A two phone simultaneously

Test charging via USB-A two phone simultaneously

Due to the short distance between ports, I could only use one USB tester, hence data is not highly accurate, but it still shows data in the ballpark. It took nearly 2 hours to charge two mobile phones at the same time. It’s nearly 5000 mAh of energy delivered. It’s a pretty decent result.

Round-up of output charging

Overall it’s a good result. The power bank delivers energy in an acceptable time frame. The high battery efficiency guarantees the use of every single drop of juice, making this a highly efficient power bank. On the flip side, neither tested phone detected fast-charging speed. It could have allowed me to charge the phone within an hour or a bit longer.

Input Charging

Both available ports Micro USB and USB-C can accept energy on level 5V/2A. Considering the battery’s capacity, it might take around 10 to 11 hours.

I charged the power bank twice. The first test, via a standard charger rated at 5V/2A charging speed; a charger most of us have. For the second charge, I used the charger rated 65W, the fastest type of charger, able to charge compatible laptops.

10 hours and 40 minutes for the full charge via Standard Charger. It’s the expected time. The power bank received in total 18,128 mAh / 92.7 Wh.

Recharging via RAVPower Fast Charger

Recharging via RAVPower Fast Charger

This is quite surprising, RAVPower’s charger, one of the fastest to buy, that can pump up energy with the fastest possible pace, needed nearly 12 hours to charge the power bank to the maximum. Nonetheless, the power bank can accept a certain amount of energy, thus still it was expected, but within 11 hours, not 12. The power bank received 18573 mAh / 96 Wh.


Design & Build

Size & Weight

Weight in ounces and grams

  • 12 oz / 342 gm

Measurement in inches and centimeters

  • 6.2 x 2.9 x 0.8 in / 15.8 x 7.4 x 1.9 cm

The PowerCore Essential 20000 is compact enough for easy transport. At 2.9 inches wide, 6.4 inches tall, and 0.7 inches thick, it’s only slightly larger than your average smartphone with a case. This makes it small enough to slip into a backpack or laptop bag, although it’s a bit large to carry in your pants pocket. It weighs 12 ounces, which is heavier than you’d expect for the size, about twice the weight of an iPhone.

Design & Material

Those who follow Charging Kick might already know that I am a big fan of Anker design. All their power banks are robust and minimalistic. The Anker PowerCore Essential is not an exception.

Anker PowerCore Essential 20000 mah design material 1 Anker PowerCore Essential 20000 mah design material 2 Anker PowerCore Essential 20000 mah design material 3

The power bank is constructed from solid plastic. There are two color selections: black and white. It has a matte finish, prevents creating smudges and fingerprints. The texture is comfortably coarse, keeping the device firmly in hand. The edges are glossy, providing a subtle contrast to the matte front and back. The corners are slightly curved. All parts are well built, and I can't find any loose parts.

The front of the power bank has a small, glossy Anker logo on one end. On the other end, is the power button the size of a fingertip. It’s easily palpable from the rest of the device, which makes it very useful if you carry it in a pocket. It has four small LED lights built into it. Once the button is pressed, the lights start illuminating, showing the current power level. If you press and keep the button for 2 seconds, it switches on the trickle charge option to charge safely low-power accessories such as earphones or smartwatches. It’s indicated as a green light.

On the bottom of the power bank, near the power button, you’ll find four USB ports. On the left side are two USB-A, used to output charging, and on the right are USB-C and Micro USB, both used to recharge the power bank.

On the back, on the bottom, you can find a list of essential information about the power bank.

Sadly the PowerCore Essential 20000 is not waterproof and shock-proof. It’s a robust power bank, great construction, but I don’t recommend it taking to the wilderness or outdoor activities. For everyday use, it should be enough.




The Anker PowerCore Essential 20000 has two USB-A ports for output charging. Both can be used at the same time to charge two devices. A handy feature for, I would consider essential, for a big power bank. Each port is limited to 5V at 2.4A, for a total of 12 Watts. While using two ports simultaneously, it’s limited to 15 Watts. In consequence, charging two devices at the same time will slow the charging time of each charged device.
For input charging, there are two options available: Micro USB and USB-C. Both supply the same charging speed.


  • 2 x USB-A Output: 5V/3A

  • USB-C Type Input: 5V/2A

  • Micro USB Type Input: 5V/2A

Anker PowerCore Essential 20000 mah usb ports


The power bank uses Anker’s PowerIQ technology, which detects automatically the voltage of the charged device to meet the optimal condition.

Sadly the Anker PowerCore Essential doesn’t have pass-through charging, so you can’t charge your mobile phone while simultaneously charging the power bank.

It doesn’t support laptop charging.

  • Fast-Charging via Leading Technology

  • PowerIQ Technology

  • VoltageBoost technology delivers an optimized charge to your devices

  • Trickle-charging mode - the best way to charge low-power accessories.

  • Anker's MultiProtect safety system



Overall Opinion

It’s a solid power bank, which has proved the reason for its popularity on Amazon (over 18,000 ratings). Simple and great design, robust material, 4 ports (2 output, 2 input), and great battery efficiency. For someone who needs a power bank for 3-4 days, it will be an ideal option to choose. However, for this capacity and Anker’s reputation, I would expect faster charging, USB-C for output charging and enough Watt output to charge laptops via USB-C PD. Still, even without these features, I want to keep it in my collection.

Final Score