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:
- 1 What is a Power Bank?
- 2 How Does a Power Bank Work? Features
- 3 How to recharge a Power Bank?
- 4 How to charge your devices the right way?
- 5 Power Bank actual output capacity, efficiency and performance
- 6 Pros and Cons of Having a Power Bank
- 7 How to buy the best Power Bank according to your needs?
- 8 List of the 20 Best Portable Chargers from Amazon (March 2019) 🚩
- 9 Can I carry a Power Bank on the plane?
- 10 Frequently Asked Questions (FAQs)
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.
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:
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:
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:
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:
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.
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:
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.
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.
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.
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):
Although the airlines are governed by these regulations, you can check their documentation on dangerous goods if they include other restrictions for portable chargers:
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
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.