20 Best Power Banks from Amazon in 2019

At PowerBank20, we have made a selection of the 20 best power banks from Amazon after a deep analysis of portable chargers models and brands.

Before presenting our selection, we would like you to know better the perfomance of a power bank with our guide:

What is a Power Bank?

A power bank is a portable charger that will allow you to recharge your mobile device at any time and anywhere you want. This accessory becomes a must for travelers who spend long hours on a means of transport without being able to recharge their phone.

With the security of a portable charger for your mobile device, you will be able to enjoy your applications, social networks and games such as Fornite without worrying about battery life.

Here on our website, we will help you choose the best power bank for you that fits the needs you really need.

How Does a Power Bank Work? Features

A power bank is basically a lithium battery with a printed circuit board (PCB) that controls its operation.

When we connect the mobile to recharge through the USB port, the power bank identifies the connected device and supplies the necessary power that such device can receive.

The following picture shows the basic components of a power bank, as you can see its construction is simple:

  • PCB: integrated circuit that regulates the voltage and protects the lithium battery from overloads. It includes a USB port and micro USB to charge devices of these kinds respectively and the lithium battery of the power bank itself.
  • 18650 lithium-ion battery with a specific capacity (mAh) and voltgje (~3.7V).

How to recharge a Power Bank?

Just like a mobile phone, a power bank is recharged through a charger, connecting it to its Micro USB or USB C input port.

In addition, most current power banks, especially high-capacity models, also incorporate the Quick Charge (QC) or Power Delivery (PD) fast charging technology at their input port.

For this reason, we must differentiate between the 2 types of recharge that a power bank has:

  • Standard Charge: it is the conventional charge that is done with any charger at a voltage of 5V.
  • Fast Charge: it is a new charging system that works with a higher voltage (9V or 12V). It requires the use of a charger compatible with this technology.
Which charger should I use to recharge my power bank faster?

Ideally, for a power bank to recharge as quickly as possible, it is necessary to use a charger that is capable of supplying a power (W) equal to or greater than that indicated in the power bank’s input port.

Although, in practice, it is advisable to use a higher power in order to prevent the charger from overheating and deteriorating in the long run.

To understand it, let’s see an example using a power bank from the Tronsmart brand and a 30W charger from the Ugreen brand.

recharge power bank tronsmart trim

The following image shows the technical specifications of the Tronsmart Trim power bank.

These specifications show that this model has 2 input ports (Micro USB and USB C) and can be recharged in both Standard Charge (5V) and Quick Charge (9V) through both ports.

powerbank tronsmart trim specifications

In the Standard Charge (5V), each port supports a maximum power of 10W (5V x 2A). Therefore, we should use a charger that has an output supplying at least 10W.

In our example, we will use the standard charging port (white color) of the Ugreen charger that provides a maximum power of 12W (5V/2.4A).

The Fast Charge (9V) system of this model can be performed by means of the Quick Charge 2.0 protocol through the Micro USB or USB C port or the Power Delivery protocol by means of the USB C port.

To do this, we must use a charger compatible with QC or PD to be able to supply the power bank with a maximum power of 18W.

In this case, we can use the fast charging port QC 3.0 (green color) of the Ugreen charger that is compatible with previous versions of Quick Charge while for the Power Delivery protocol it would be necessary to use another charger compatible with this technology.

In our testing with this model, the charging times obtained in the Tronsmart Trim power bank were:

  • Standard Charge 5V: 5h
  • Fast Charge QC 2.0: 3h 30min
  • Fast Charge PD: 3h 25min
Can I charge a device while recharging the Power bank?

This function is known as Pass Through Charging and allows you to charge a device connected to the power bank while it is recharging.

Through the Pass Through Charging technology, the Power Management Integrated Circuit (PMIC) of the power bank manages the energy supplied by the charger so that a part of its charge is transferred directly to the connected device.

Generally, depending on the model, some manufacturers give priority to charging the device as soon as possible, while others give priority to charging the power bank at the expense of reducing the charging speed of the device and even increasing the power of the charger, thereby overheating the power bank.

Regardless of how the Pass Through Charging is performed, our recommendation is to avoid simultaneously charging of both devices as it affects the useful life of the power bank’s battery by spending more time recharging.

How to charge your devices the right way?

You can charge pretty much any device with an USB charging port using a power bank, including, but not limited to: cellphones, tablets, iPad, bluetooth speakers, e-book readers, smart bands, and so on and so forth.

On top of that, you can make use of the fast charging technologies (such as Quick Charge and/or Power Delivery) through the output ports (either USB-A or USB-C) of any power bank, hence, we can distinguish two different ways to charge our devices:

  • Standard Charge: the output voltage is always of 5V, this is the default charge offered by any power bank.
  • Fast Charge:  It works with a output voltage greater than 5V (such as 9V or 12V) in order to supply more power to the device during the charging process.

Note: The power bank must be compatible with the fast charging protocol implemented on the connected device, otherwise, it will trigger the default charging mode at 5V.

The following image shows the technical specs of model PBD01 by Tronsmart:

powerbank tronsmart trim specifications

It can be seen on the label the type of USB output ports: USB-A and USB-C, the range of charging tensions supported: 5V-12V and the maximum current values (A) and power (W) supplied by each port:

  • USB-A Output: DC 5-6V/3A, 6-9V/2A, 9-12V/1.5A (18W)
  • USB-C PD Output: DC 5V/3A – 9V/2A – 12V/1.5A (18W)

Note: although the type C port shows the Power Delivery protocol, we also verified that it supports Quick Charge 3.0.

That is, with this power bank we can charge devices in both Standard Charge (5V) and QC 3.0/PD Fast Charge through its 2 output ports: USB-A and USB-C.

Being that said, you may come up with the question:

What smartphones can we charge with this power bank?

Lets see some examples:

Google Pixel 3

The Google Pixel 3 has type C port and fast charging via the Power Delivery (PD) protocol only.

If we connect Pixel 3 to port C of the Tronsmart Trim power bank, its Fast Charge system would be enabled (compatible with PD) and the Pixel 3 will charge in less time than Standard Charge mode.

Instead, if we connect it to the USB-A port of the Tronsmart Trim (by using a USB-A to a USB-C cable), the Google Pixel 3 would charge at 5V (Standard Charge) since this port is compatible with QC 3.0 and the Google Pixel 3 doesn’t support Qualcomm Quick Charge protocol.

Xiaomi Mi 5

The Xiaomi Mi 5 counts with a type C port and fast charging through the Qualcomm Quick Charge (QC 3.0) protocol.

In this case, the Xiaomi Mi 5 may be plugged to the USB-A or the USB-C provided by Tronsmart Trim to be charged via QC 3.0.

Logically, for the USB-C port we would need a cable with USB -C connection in both ends.

If my smartphone charges at 1A, could the Power Bank damage it?

It will not damage your smarphone: a power bank always provides the current that the connected device needs and, of course, that it is able to supply (depending on its specifications).

The current (A) that appears in the specifications of a power bank indicates the maximum current that the power bank can supply per port at a determined charging voltage (5V/3A, 9V/2A and 12V/1.5A) but is not the current that is supplied to a device.

Power Bank actual output capacity, efficiency and performance

The indicated capacity in a power bank is the nominal capacity of its internal battery at a determined voltage, generally it is in the range of: 3.6V, 3.7V, 3.8V or 3.85V.

But the above mentioned capacity is not the actual output capacity that we have available in a power bank output to charge a device, that is:

We have already seen in the Power Bank’s specs, the range of possible voltages you may have in its USB output port: 5V, 9V or 12V.

That said, during the charging process of a device (or discharging the power bank), the internal circuit of the power bank increases the battery voltage (e.g. 3.7V) to the charging voltage of the device (e.g. 5V).

This process of conversion of voltage has an energy cost in which some energy is wasted in the form of dissipated heat.

Depending on the design and quality of the internal circuit components, the power bank will be more or less efficient to transfer its stored energy to the devices to be charged.

Therefore, we can define the discharging energy efficiency of a power bank as the energy it is able to supply based on its stored energy:

Power Bank discharge efficiency = output energy / input energy

Pros and Cons of Having a Power Bank

Are power banks necessary?

Below, we list the advantages and disadvantages of the need to have a portable charger as an accessory for our mobile phones.


The mobile phone has become the center of our lives, we communicate through WhatsApp, we manage our trips (ticket purchases, reservations …), we send emails, we buy online, we have fun on YouTube, social networks… and we now even pay through it.

For this reason, we believe that our mobile phone always has to be available at any time of the day without worrying about the lack of battery.

A portable charger is our great ally, as it allows us to stay always connected and guarantees that we will have extra energy to reach the end of the day. These are some of the most important advantages:

Its main feature is that it is a portable battery you can carry in your backpack, purse, coat … and even in your pants pocket since it takes up little space.
Have you ever run out of battery at the least suitable moment? It is a very practical accessory because of the problems it can solve for us when we do not have access to any plug.
Easy to use
A hassle-free accessory, connect the USB cable to your mobile phone and you’re done.
Small dimensions
The portable chargers we recommend always have a small and compact size so that they do not become another “piece of junk” to carry.
In general, it is compatible with any electronic device with 5V micro USB input: Android, iPhone phones, sports cameras such as the Go Pro, tablet, iPad, bluetooth speaker…


And what about the disadvantages? Like any other product, portable charges also have their drawbacks:

Have you thought about whether you really need to buy a Power Bank?

If you spend all day away from home or you often travel frequently, it may be useful to carry a portable battery, but, if in your everyday life, you see that you have enough battery in your mobile phone until you get home, you can avoid buying an extra gadget…

On the other hand, a low quality power bank can be dangerous and even explode due to a factory defect or a user’s misuse.

It is advisable to always read the manufacturer’s instructions, look for specialized brands in those products and flee from super low-priced offers.

How to buy the best Power Bank according to your needs?

The market is full of different power bank kinds and brands. It is very important to know what brand and type is best for your needs and budget.

At PowerBank20 we recommend to take the following points into account to choose the most appropriate model:

5 tips to choose a Power Bank

1. Capacity (mAh)

Generally, the capacities of portable chargers vary from 2600 mAh to 30000 mAh. Mobile phones usually have a battery between 1500 mAh up to 5000 mAh (the most recent models), while on a tablet or iPad capacity is between 8000-12000 mAh. With this you can get an idea of what your requirements are.

We recommend to choose a portable charger with twice the capacity of the device to be charged to ensure you will always have a full charge, since part of the energy is lost during the charging process, being the useful capacity lower than the stated one.

2. Price

Generally, the price is linked to the capacity of the portable charger, but also depends on other factors such as the brand, size, construction material … However, here you can find quality portable chargers from 10$.

3. Size

Size is an important point when choosing a portable charger. Normally, the greater the capacity, the bigger the size: a power bank of 5600 mAh is not the same as a power bank of 20000 mAh. Although we will always be interested in choosing a size that is comfortable to carry.

4. Portability:

Along with size, portability is one of the main reasons behind the enormous popularity of power banks.

Many brands focus on improving this factor by using more compact lithium battery cells since users with a portable charger look for a simple alternative to the lack of power in their phones without having to carry uncomfortable accessories.

5. Quality:

Something very common and attractive is to find a portable charger with high capacity and at a low price.

Although it is a smart sales tactic, the buyer does not usually understand that the fact that the capacity is high and cheap means that other components of it may not be as good as they should be.

This then affects the security of your phone, so we advise you to choose specialized brands in this type of products that also include a guarantee. Flee from cheap white-label brands!

After reading our tips, you can see that the market is full of different models, brands and qualities for portable chargers.

If you want to find the most suitable option for you, first you have to know exactly what you need to charge and how much you are willing to spend and then choose a power bank that suits that price.

List of the 20 Best Portable Chargers from Amazon (March 2019) 🚩

To save you this whole process of searching for a quality power bank and after having thoroughly studied the market of portable batteries, we have developed our list with the 20 top models you can find in Amazon in a wide range of prices, sizes and capabilities.

This is our current list for the month of March 2019. Remember that you can also visit the top-selling portable chargers on Amazon here.

How we select the best Power Banks from Amazon

We based our selection of the 20 Best Power Bank on multiple factors and technical features of the model, besides the Amazon customer’ reviews and the model’s status.

In the process of adding each portable charger to the list, we carefully look at user reviews and ratings for a specific model, its status and rating on Amazon, and we also have in mind the opinion of our own experts in consumer electronic devices.

Many of our choices agree with consumer preferences and they are also Amazon’s best seller. Although, so many deserve the award of the best power bank of March 2019, we also included portable chargers that does not belong to the list mentioned above and, nevertheless, we believe that their quality and value are enough to include them in our list.

In our research of the best portable charger, the process of assessment was based essentially in the evaluation of the following features of each picked model:

Capacity (mAh)Amperage (A)PortabilityUseful life of the batteryExtra features

The capacity expressed in milliamperes hour or mAh, shows the quantity of energy that can be stored. When you are buying an external battery, you have to consider your needs: if you plan to use it only for emergencies, batteries from 3000 mAh – 5000 mAh assortment should be pretty enough to supply 1 or 2 complete charges to your phone.

However, if you plan to use it for more than just one mobile phone or Tablet, maybe you ought to consider an external battery with a capacity of 10000 mAh or more. You must have bear in mind that a larger the capacity mean a bigger size of the battery charger.

All of our chosen portable chargers have at least 3000 mAh for compact models and 10000 mAh or more for the huge models, used to charge numerous phones or tablets.

The greatest capacity of our external batteries belongs to a power bank called RAVPower, with an amazing capacity of 20100 mAh, which should be enough to charge numerous times your phone and Tablet.

The amperage, measured in Amperes (A), shows us how fast goes the current through the USB port to the battery of our mobile. Then to a higher amperage less time of charge, this statement works for both: external battery chargers and for usual chargers.

power bank poweradd

At the moment of choosing the best external battery, you need to check that the amperage of the USB port is 1A or greater.

If you have ever tried to charge your tablet or even a phone using the USB port of your laptop, the odds are that you have seen that the battery of your device charged very slowly or did not straightaway charged at all.

The reason for this behavior is that the USB ports of a standard laptop are barely 0.5A and charging any device from a port with that amperage, in the best case, takes an extremely long time.

When you are choosing a power bank for your pone, you must ask yourself some questions around your planned purpose with the external battery.

For example:

How will you carry the power bank? Are you going to carry it in your purse, in a pocket … in your backpack? And your mobile is the only device that you will charge?

If so, you ought to choose a smaller model. There are some power bank that have the size of a lipstick.

power bank anker astro

All external batteries in our list, even the smallest models, must supply at least one full charge for your phone or more than 50% of its capacity.

All of the power bank that we have selected have the modern technology based on lithium ions (they are not liable of “memory effect” that was very common on the old models of external batteries) and they can last, at least, 500 complete load cycles (1 load cycle = from 0% to 100 % or 2x[50% to 100%]). Therefore, even with daily use, they have to last, at least, 2 years.

In some situations, you should consider external batteries that have additional characteristics that meet your special needs. In our selection, there are models that have extra features like LED flashlight, Quick Charge and even USB type-C among others.

Can I carry a Power Bank on the plane?

Many users wonder if it is possible to carry a portable charger on the plane and the answer is YES, IT IS POSSIBLE AS HAND LUGGAGE.

According to the International Air Transport Association (IATA) in its Dangerous Goods Regulations, the power bank is considered as a spare battery and can not be checked-in, it can only be carried as hand luggage, as long as it does not exceed the nominal capacity of 100 Wh(Watt-hour):

Batteries, spare/loose, including lithium metal or lithium ion cells or batteries, for portable electronic devices must be carried in carry-on baggage only.

For lithium metal batteries the lithium metal content must not exceed 2 g and for lithium ion batteries the Watt-hour rating must not exceed 100 Wh.

Articles which have the primary purpose as a power source, e.g. power banks are considered as spare batteries.

These batteries must be individually protected to prevent short circuits. Each person is limited to a maximum of 20 spare batteries. *The operator may approve the carriage of more than 20 batteries.

Although the airlines are governed by these regulations, you can check their documentation on dangerous goods if they include other restrictions for portable chargers:

AirlineHand LuggageRegulations
Alaska AirlinesCheck
Allegiant AirCheck
American AirlinesCheck
Southwest AirlinesCheck
United AirlinesCheck

How to calculate the Wh?

Typically, the power bank specification sheet usually indicates its rated capacity in Ah y Wh but if you can not find it you can always calculate it for yourself:

As you will already know, a power bank consists of a set of lithium-ion batteries with a certain capacity and a common voltage of 3,7V.
To know the rated capacity in Watt-hour (Wh), you must multiply the power bank’s total capacity indicated in mAh by this voltage and divide it by 1000:

Rated Capacity (Wh) = (mAh x V) / 1000

For example:

If our portable charger has a capacity of 20000 mAh at a voltage of 3,7V, the rated capacity will be:

Rated Capacity = (20000 mAh x 3,7V) / 1000 = 74 Wh < 100 Wh ✅

In the event that you carried in your hand luggage 2 portable chargers, you would have to add the total capacity and verify that you do not exceed 100 Wh:

  • Power bank 10000 mAh = 37W
  • Power bank 20000 mAh = 74W

Total Capacity = 111 Wh > 100 Wh ❌

Frequently Asked Questions (FAQs)

If you have any other doubt that has not be answered, you can write it in the comments below.

What can I charge with a Power Bank?
You can charge almost any kind of electronic device with an entry of 5V: mobile phones, tablets, iPhones, iPads, e-books, kindles, Bluetooth speakers, Go Pro and even electronic cigarettes.
What is included besides the Power Bank?
Usually, it is included the external battery and a USB/microUSB universal cable to recharge. It does not include a wall charger.
How do I recharge a Power Bank?
You have to connect one end of the USB cable to the powerbank and the other end to the USB port of the computer or grid circuit. On this last case, you need to use a mobile charger. We recommend you to charge with grid circuit in order to save time (takes less time to charge).
How long does it take to charge a Power Bank?
The charging time varies depending on the chosen method (PC or charger) and the capacity of the portable charger itself. Some models have LEDs that indicate the level of the battery during the charging process.
What load capacity do they have?
As any other battery, the charging capacity change from one to another. In the case of Power Bank, we recommend capacities between 2,600 mAh  – 25000 mAh.
How do I choose the most suitable Power Bank for my mobile device?

To be able to choose the most suitable mobile phone battery, you must first know what capacity of mAh (milliamperio-hour) has your mobile device and based on that, you will choose an external battery with a higher number of mAh. For example: if you want to buy a power bank charger for your mobile that has a battery of 5600 mAh and you buy one with the same amount of mAh, the device will not complete its battery charge. But, if you buy one of 20000 mAh, you will be able to recharge your mobile phone up to 100%. Remember that mobile’s battery also uses energy in the charging process.

How do I take care of / optimize my Power Bank?
  • The Power Bank needs at least 5 complete load and unload cycles   for optimization.
  • You must preserve the cable of the mobile battery in good condition, therefore, you should move away it from sharp objects and pets.
  • Al momento de la descarga de tu batería móvil la temperatura ambiente no debe superar los 45 grados centígrados y al momento de la carga no debe superar los 25 grados centígrados. At the time of downloading your mobile battery, the room temperature should not exceed 45 degrees centigrade and when you are charging it should not exceed 25 degrees centigrade.
  • Do not wash the Power Bank or expose it to abrasive products.
  • Avoid hits and falls.
  • If your mobile battery is broken, bloated or poor working DO NOT USE.

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