Welcome to PowerBank20! An independent website where we test portable chargers – also known as Power bank – on Amazon in order to recommend the best 20 models.
We know the difficulty of choosing a quality and good-performance power bank to charge our devices due to the infinity of brands and models we can find on Amazon with different features and prices.
For this reason, we have 2 clear goals:
- Choose the 20 Best Power banks on Amazon: we constantly research the market and test new portable chargers with the aim of recommending those that really surprise us and are worthwhile.
- Turn our readers into Power Bank Experts: by reading this Guide, you’ll learn everything you need to know to buy the model that best suits your charging needs.
No time to read? No problem! In the following list, you can see the 20 Best Power banks we recommend from Amazon for the month of November 2023.
Our selection criteria is based on everything we explain in this guide and our experience after analyzing more than 50 models.
The following icons will make it easier for you to identify the most relevant features of each model:
- ⚡ QC 3.0 18W and/or PD fast charging
- 📶 Wireless charging
- 🔘 Magnetic wireless charging
- 🌞 Solar charging
- 🔌 With 220V socket
- 💻 For charging laptops
- 🚗 For starting cars
- ✅ Tested
Update: As of 2023 all models recommended in this list include USB-C as an input and output port.
We encourage you to read our Guide and share it on your social networks and, of course, if we aren’t able to solve your doubts, you can leave us your question in the comments section below and we’ll answer gladly! 🙂
- 1 What is a Power bank?
- 2 How does a Power bank work? Features
- 3 How to recharge a Power bank the right way?
- 4 How long does it take to recharge a Power bank? ⌚
- 5 How to charge your devices with a Power bank?
- 6 Power bank actual output capacity, efficiency and performance
- 7 How many times can I charge my phone with a Power bank? 📱
- 8 How to buy the best Power bank according to your charging needs?
- 9 How we choose the best Power banks
- 10 How we tested a Power bank ✅
- 11 Frequently Asked Questions (FAQs)
What is a Power bank?
A power bank is a portable charger that will allow you to recharge your smartphone anytime 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 electronic devices, you will be able to enjoy your applications, social networks, and video games without worrying about battery life.
On our website, we assist you in selecting the most suitable power bank that aligns perfectly with your charging needs. Here’s a breakdown of the various power bank options available:
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 smartphone to recharge through the USB port, the power bank identifies the connected device and supplies the necessary power such device can receive.
The following picture shows the basic components of a power bank, as you can see its construction is simple:
- PCB: an 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 voltage (~3.7V).
How to recharge a Power bank the right way?
Just like a smartphone, a power bank is recharged through a charger or adapter, i.e. one end of the charging cable is connected to the Micro USB or USB-C input port of the power bank and the other end to the USB-A or USB-C output port of the charger.
In addition, the most current power banks – especially high-capacity models – incorporate the Qualcomm Quick Charge (QC) or Power Delivery (PD) fast charging protocol in their input port.
For this reason, we must differentiate between the 2 types of recharge that a power bank has:
Now, which charger should I use to recharge a power bank faster?
Ideally, for a power bank to recharge as quickly as possible, it is necessary to use a charger capable of supplying a power (W) equal to or greater than that specified on the power bank’s input port.
Although, in practice, it is advisable to supply a higher power to prevent the charger from overheating and deteriorating in the long term.
Therefore, the first step would be to identify the maximum power allowed at the input port of the power bank:
Typically, in standard recharging (5V), the input port of a power bank usually supports maximum power of 5 watts (W) (5V/1A), 10W (5V/2A), 12W (5V/2.4A), 15W (5V/3A).
While if the input port supports Quick Charge (QC) and/or Power Delivery (PD) fast charging the power bank can charge at 18, 30, 45, and even 100 watts (W).
The following image shows the specifications of a 10000 mAh power bank:
We see that this power bank has 2 USB input ports and each of them supports a maximum power depending on the charging mode:
|Port type||Standard Charge||QC Fast Charge||PD Fast Charge|
|Micro-USB||10 W max.||18 W max.||–|
|USB-C||15 W max.||–||18 W max.|
The next step is to look for a charger that meets the following 2 requirements so that the power bank is recharged in the shortest possible time:
- Its output ports can supply the maximum powers indicated in the table above.
- It is compatible with Quick Charge and Power Delivery fast charging protocols.
Remember that for QC and/or PD fast charging, it is also required that the charging cable is compatible with the protocol in question.
Normally, this cable is included with the power bank.
But, for example, if you buy a charger with fast charging and then use an old cable you have at home, then only standard charging will be activated.
Also, don’t forget other factors such as the length, cross-section, and condition of the cable, which will also affect the charging time of the power bank.
Here is a case study with a power bank analyzed by our team:
How long does it take to recharge a Power bank? ⌚
As seen in the previous section, the charging time of a power bank depends on the charger and cable used, as well as the power bank’s own specifications.
Also, another influencing factor is the energy efficiency of the recharging process, ie:
To achieve a full recharge of the power bank, any charger will always supply more energy than is stored in the internal battery of the power bank.
This excess energy, manifested in the form of heat, will depend on the quality of the cable used and the internal circuitry of the power bank that manages the battery charging process.
The energy efficiency in recharging a power bank can be expressed by the following formula:
Recharging Efficiency = (Power bank stored energy / Charger supplied energy) x 100.
In our tests, we found that the average efficiency in the Standard Recharge process (5V) of a power bank was 85%.
This means that the charger must supply 15% more energy than the power bank’s internal battery stores.
With this information, we can use the following formula to estimate the minimum time required to recharge a power bank fully:
In addition, the following considerations must be taken into account in order to use this formula:
- The power bank charges constantly at the maximum power indicated on the USB input port.
- A charger that supplies this power is used.
- The efficiency of the recharging process is 85% (multiply by 1.15).
Logically, a power bank does not recharge at a constant power nor is it possible to know the energy efficiency when recharging, but using this formula allows us to know in advance the estimated charging time.
For example, if we are interested in buying a high-capacity power bank, for example, 20000 mAh, and we have seen 3 models with a similar price, we can use this formula to choose the model that charges faster:
|Models||Max. Input Power||Min. Charging Time|
|PB01||5 W||(74 Wh / 5 W) x 1,15 = 17 h|
|PB02||10 W||(74 Wh / 10 W) x 1,15 = 8,5 h|
|PB03||18 W||(74 Wh / 18 W) x 1,15 = 4,7 h|
Finally, in the following table we can analyze, with real data, the time and efficiency of the charging process of some models tested by our team, both standard and fast charging:
|Brand||Model||Recharge Type||USB Input Port||Charging Time (h)||Avg. Charging Voltage||Battery Energy (Wh)||Supplied Energy (Wh)||Recharging Efficiency (%)|
|Poweradd||Pilot Pro 4||Standard||Micro-USB||17.62||5.3||99.16||143.04||69.32|
|EC Technology||PB05||QC 2.0||USB-C||6.01||9.52||99.16||89.1||111.29|
How to charge your devices with a Power bank?
In this section, you will learn to identify the specifications in the USB output ports of your power bank, in order for you to choose the model that satisfies best your device’s charging needs.
As you already know, a power bank is able to charge most electronic devices with a USB port: cellphone, tablet, iPad, bluetooth headset, ebook reader, fitness tracker, smartwatch… even an E-cigarette or a laptop.
In addition, for the new generation cellphones, fast charging technologies (such as Quick Charge and/or Power Delivery) are also available in the output ports (either USB-A or USB-C) in many power bank models, therefore, we can distinguish 2 different ways to charge our devices:
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.
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 discharge 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
In order to have a better understanding of this formula, let’s see an example:
On the Model PB108 specifications of the Ugreen brand, it shows that it has a battery with a nominal capacity of 10000mAh (milliamps per hour) at a voltage of 3.8V (volts) being the stored energy of 38Wh (watts per hour), this results of multiplying capacity (Ah) by voltage (V): 10Ah x 3.8V.
If we completely discharge the Ugreen power bank, we will get the actual capacity and energy available to supply our devices:
|Type of charge||Actual output capacity||Output energy||Conversion Rate|
|Standard (5.1V/2A)||6864mAh||34.89Wh||34.89/38 = 91.82%|
|QC 3.0 (7.3V/1,9A)||4701mAh||34.34Wh||34.34/38 = 90.37%|
As you can see in the table above, the actual capacity obtained would be different depending on the tension we charge our devices: 5.1V or 7.3V.
Although it’s not a very common practice in power bank manufacturers, in this case, Ugreen already indicates us that the minimum output capacity is 6500mAh (or 33.15Wh) for Standard Charge (5.1V/1A).
Efficiency vs Performance
No matter how efficient a power bank may be, what is its purpose? really, do you know what its main purpose is?
The purpose of a power bank is to charge one or more devices as many times as possible.
Put in different words:
The more power a power bank can supply, the more devices can be charged.
Obviously, the larger capacity (mAh) a power bank has, the most energy it stores (Wh) and, thus, the greater number of devices it will charge (unless it has poor energy efficiency).
That is to say that with a 20000mAh power bank, you will be able to charge more devices than with a 10000mAh since the stored energy is larger: 74Wh vs 37Wh.
However, when comparing models with the same capacity, we should not focus only in knowing which one is more efficient, but also, which one can supply more energy, because the nominal voltage of the battery that incorporates the power bank plays an important role.
For this reason, when we talk about the performance of a power bank, we are referring to the number of possible charges the user will be able to get on one or more devices.
Commonly, the more efficient a power bank is, the more stored energy it can supply, although we may also find other less efficient models that provide more energy, i.e. they have a better performance.
The following table shows the energy and efficiency results obtained in the Standard Discharge (5V) of several power banks with the same capacity:
|Power bank||Rated capacity||Battery voltage||Stored energy||Output energy||Conversion rate|
Both models have a battery with the same rated capacity and voltage, so, they accumulate the same energy (37Wh).
In this case, the most efficient power bank will be the one with the best performance: Omars.
These models have a battery with the same rated capacity but different tension, being the stored energy larger in the Ugreen power bank (38Wh).
Although Omars is more efficient than Ugreen (93.73% vs 91.82%), it supplies less energy (34.68Wh vs 34.89Wh), so, before the user, Ugreen has a better performance than Omars.
Finally, we see that Aideaz is the power bank that supplies more energy (35.83Wh) with less stored energy (36Wh) being also the most efficient model (99.53%).
In terms of energy, Aideaz could be considered an ideal power bank:
It is capable of transferring its stored energy to the connected devices with the lowest energy waste (most efficient) and the highest possible number of charges (most performance).
How many times can I charge my phone with a Power bank? 📱
With the following tool, you can find out the number of charges that you will have on your smartphone through the Standard Charge of a power bank:
How to buy the best Power bank according to your charging needs?
In this section, we will highlight the most important features you need to take into account when buying a power bank, according to your charging needs.
Before starting, we would like you to answer the following questions that will help you to have a clearer idea of which type of power bank you are really looking for.
- What kind of device do you need to charge with a power bank: smartphone, tablet, iPad, laptop, bluetooth earphones, smartband, camera…?
- How often will you use it? Only on trips, on a daily basis…?
- How many times do you want to charge your phone with a power bank?
- Do you need your power bank to have a fast charging system?
The more capacity (mAh) a power bank has, the more times you can charge your devices but it also affects their size, weight and price.
For this reason, we say that it is important to be clear about which devices you are going to charge and how often:
For example, during trips or travels, it is recommended to use a 20000 mAh power bank to charge your smartphone and other devices without having a power plug for several days.
Tip: If you need more capacity but you are going to take a flight, please check that the power bank can be brought on a plane.
Now, if your idea is to use a power bank daily to charge your smartphone at work, college, or school… a 5000mAh power bank or a 10000mAh one it will be more than enough for a full charge, besides the practicality to carry it with you.
Are you looking for a power bank that allows you to have N number of charges on your smartphone? If so, then you can check in the previous section what power bank capacity you will need.
Generally, the amount of USB output ports of a power bank will depend on its capacity, that is to say:
High-capacity power banks (10000 mAh or more) usually include at least 2 output ports to allow multiple devices to be charged at the same time, whereas other models with smaller capacities (5000-6000 mAh) have a single USB port because they are designed to charge phones only.
Obviously, there are exceptions to this, as in the case of some models of 10000 mAh of the Anker and RAVPower brands which include only one USB port.
Choosing the number of ports of the power bank will depend on the individual needs of each user. Prior to selecting a particular model, remember to ask the following question:
How many devices are you planning to charge? Are you going to share your power bank with your relatives or friends?
It is important that the power bank be light and easy to carry so it may not become an unnecessary and useless gadget.
After all, the user is interested in carrying portable power in a device that takes up as little space as possible.
Normally, the more capacity the power bank has, the larger its size, thickness and weight.
However, the use of lithium polymer batteries (LiPo) which substitute the classic 18650 ion lithium (Li-Ion) ones, have achieved to reduce the thickness of the power banks and thus offer more compact models, with dimensions and/or thickness similar to that of a smartphone, an example of this would be the Ultra Slim models.
Currently, a power bank with fast charging technology generally has a higher tag price than a power bank that only offers standard charging. However, this has its advantages:
- 2×1: This offers both Fast Charge as well as Standard Charge for each of your devices.
- High-capacity power banks can recharge in less time.
- Current and future smartphones use fast charging technology.
Deciding on whether or not to choose a fast charge power bank will only depend on what devices you will need to charge and on your budget. Besides, many brands offer the same power bank model without a fast charge.
To sum up:
If your smartphone doesn’t have this technology and you are not thinking to change it in the near future then you may buy a simpler and more affordable power bank.
On the other hand, if you want to enjoy the fast charge in your smartphone, the power bank must be compatible with the fast charging protocol of your smartphone: Quick Charge, Power Delivery, Huawei FCP, Dash Charge…
Do you have a phone with a USB-C charging port?
The new reversible USB type C port is present in the new mobile generation and the trend is that it will keep on growing in the future as the substitute for the classic micro USB port.
Similarly, the new power banks come with the USB-C port as an additional port or as a substitute for the micro USB input port, since it may work as an input-output port.
In addition, the fast charging protocol or Power Delivery is designed to only work with this port.
This is why, if you have a smartphone with a USB C port or you are thinking to purchase a new device in the future, it is advisable to use a power bank with a USB C port.
It is always important to check the technical features of the power bank you are going to buy and compare them with similar models of other brands. For this, ask yourself the following questions:
- What type and how many USB input ports does the power bank have to recharge?
- Does it come with a micro USB, Lighting port, or does it include the new USB type C port?
- Does the micro USB port support Qualcomm Quick Charge (QC) technology or it only has the Standard Recharge (5V)?
- Similarly, does the USB-C port support Qualcomm Quick Charge (QC) and/or Power Delivery (PD) or it only has the Standard Recharge?
- In the case of Standard Recharge, what’s the maximum power admitted in this port? 5W (5V/1A), 10W (5V/2A), 12W (5V/2A), 15W (5V/3A…)?
Tip: the more power (W) the power bank admits, the less time it takes to recharge it.
- What types and how many USB output ports does the power bank have for charging devices?
- Does it have a USB-C port or only the classic USB-A?
- Do USB-A ports support Quick Charge or only work with the Standard Charge?
- Likewise, does the USB-C port support Quick Charge and/or Power Delivery or only Standard Charge?
- In the case of Standard Charge, what’s the maximum power that each port can supply? 5W, 10W, 12W, 15W…?
Tip: The more power (W) the portable charger can supply, the faster your devices will charge.
Finally, you may also find power banks with accessories and additional features that adapt to a particular need, for instance: It
- comes with an integrated cable
- has an LCD screen to visualize the charge level
- has a LED flashlight
- is water resistant or anti-shock power banks
- works as a jump starter.
How we choose the best Power banks
We find difficult to establish a single criterion to choose the 20 Best Power Banks, since many factors must be taken into account depending on each user’s charging needs and, of course, on their available budget.
However, after having compiled a large amount of information on the features and operation of many power banks in the market, we think we can establish a reliable criterion to recommend the best models.
Before starting, we would like to clarify 2 concepts that might confuse the user:
- The user should not confuse the official ranking of Amazon’s best-selling power banks with Amazon’s best power banks.
- A power bank with more ratings does not always mean that it is better than another model with a lower rating.
Here are the main factors we have taken into account to choose the best portable chargers on Amazon:
Although product appearance is not the most relevant factor, we attach some importance to packaging, i.e. how the seller presents and protects the powerbank and what information it displays in the box itself, as well as the contents of the box:
If the powerbank has a USB-C port, we will value that a cable with a USB-C connector or an adapter for it is included.
In addition, if the powerbank supports fast recharge through Power Delivery, we will value that the same cable is compatible with this technology so that the user does not have to buy an additional cable…
Also, we appreciate small details that the brand has with its customers, such as including a little carry pouch or a Lightning adapter.
Containing flammable batteries inside, the powerbank must be made of material resistant to knocks, falls and scratches and, obviously, include protection circuits against short circuits and overvoltages in order to protect your devices.
Some brands use aluminum housings while others opt for high-quality plastic and even some models are covered with rubber to isolate them from blows or to improve their grip (anti-slip).
Although powerbanks with aluminum housing have an aesthetically pleasing design, they are also more prone to scratches and dents. We prefer more robust models made of high-quality plastic.
We value those powerbanks that offer the same benefits as other models but with a smaller size and lighter weight.
We are supporters of the powerbanks that meet the charging needs of the current smartphone market: the models with fast charging technologies, wireless charging and USB type C port have a more significant presence in our ranking.
For example, we consider, almost essential, that the input port of a large capacity powerbank (>= 10000 mAh) has a fast charging system (Quick Charge and/or Power Delivery) in order to avoid long waiting times.
However, we’ve also wanted to recommend some models without fast charging (only standard charging) for those users who are looking for a simpler and cheaper powerbank.
What other features do we consider?
- Admitted power at the input port: a powerbank that recharges to 5W (5V/1A) is not the same as another that recharges at 10W (5V/2A).
- USB output ports: it should have at least 2 ports (USB-A and/or USB-C).
- Power supplied to a device: Which powerbank supplies more power per port? What is the total power it can deliver among all its output ports?
We also like to rate who is behind the product and what guarantee it offers to the customer:
- Is it a company specialized in smartphone charging devices? Or is it a seller who only imports products of questionable quality from China?
- What guarantee does it offer if the powerbank fails a year after purchase?
Until now, all the factors analyzed can be checked by the readers themselves with the product information available on Amazon.
Also, if you also read the previous sections of this guide and our buying tips, you must already be a powerbank expert!
However, there are other important parameters to analyze in order to distinguish between a good and an average model.
But, to do this, it is necessary to have the powerbank in your hands and test it thoroughly. That is our job!
For that reason, in our valuation criterion, we take into account the different tests performed on a powerbank:
- Efficiency in recharging
- Efficiency in discharging
- Maximum power/port
- Total power reached
- Standard and fast simultaneous charging
- Fast charging protocols supported
- Low Power Mode
- Charge devices and powerbank at the same time (Pass-Through Charging)
Our goal is to recommend quality powerbanks (previously supervised by our technicians) that offer the best performance at the lowest price.
How we tested a Power bank ✅
At Powerbank20, we aim to recommend to our readers the best Amazon power banks in a critical and neutral way, that is:
Without being influenced by the customer reviews of Amazon and the “advertising” recommendations of influencers and webs from the tech sector.
In order to accomplish this difficult task, we must buy, test, and compare a large number of power banks of different brands, features and prices.
Below, we will describe the technical tests performed on each power bank that will help us decide, along with other factors, which are the best ones:
Charging and discharging test
A full charge and discharge of the power bank is made by measuring each stage with a USB multimeter:
Thanks to these measurements, we can know, among other data, a power bank’s charging time, its real capacity or how efficient it’s to recharge and discharge it.
In addition, we’ve created a basic report in real time that answers the following questions of general interest for our readers.
Simply select the type of discharge: Standard (by default), Quick Charge or Power Delivery and the capacity to compare among several power banks correctly :
A device will charge faster with a power bank that can supply the power required by said device, that is:
If the device can be charged at 10W of power, the power bank should be able to supply those 10W (5V/2A) without problems.
Also, if the power bank has 2 or more USB output ports and we want to charge several devices at the same time, it is important to know the total power the power bank can supply.
In our tests, we checked the maximum power that each USB output port of the power bank can provide and the total power that all the USB output ports can supply at the same time.
Finally, we performed other checks that can make the difference between one model and another:
- Pass-Through Charging: if you can charge a device at the same time as the power bank is recharged.
- Low Power Mode: if you can charge low-power devices such as smartbands, Bluetooth headsets…
- Simultaneous Standard and Fast Charge: when we charge several devices at the same time, if the power bank is able to maintain the Fast Charge function or, conversely, disables it by working all its ports in Standard Charge.
Frequently Asked Questions (FAQs)
If you have any other questions, don’t hesitate to reach out in the comments section below!