Last updated: August 11, 2021

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Everyone has had this problem: you're on the road and forgot to fully charge your mobile phone at home beforehand. You want to be able to charge your mobile phone anywhere without a power socket at any time? Then you should think about buying a power bank. With a power bank, you can literally charge your phone at the touch of a button without a power outlet. What are the mistakes to avoid when using a powerbank? What are the different types of power banks you can buy?

You can find answers to the most frequently asked questions here in the big powerbank test 2021. We present various powerbank products to help you make your purchase decision. In addition, you will find helpful tips and tricks in our guide on which criteria are decisive for your powerbank purchase. No matter whether you decide on external battery blocks, outdoor power banks or battery cases, we will tell you about the advantages and disadvantages of the different charging types for your mobile phone.

The Best Powerbank: Our Picks

Guide: Questions you should ask yourself before buying a power bank

Who is a power bank suitable for?

Nowadays, many people use different mobile electronic devices, such as smartphones, laptops and tablets. If you are one of these people, you certainly know the problem that the batteries often run out quite quickly and you want to charge your battery on the go. Powerbanks are designed for this purpose, so that you can use the practical energy storage device when you are on the move.

A power bank is therefore suitable for everyone who wants to charge their electronic devices while on the move.

What and how can I charge with a powerbank?

You can charge virtually all electronic mobile devices with your power bank. However, they are most commonly used for smartphones, laptops and tablets.

What capacity do I need for my powerbank?

First of all, it is important to know how much battery capacity is in your device. The capacity of the batteries is always specified by the manufacturers in mAh (milliampere hours) and can be found in the technical details.

The capacity of the power bank should be at least twice as high as the capacity of the device to be charged in order to guarantee a complete mobile charge. Because: the powerbank generates heat during the charging process and thus loses energy. Therefore, a certain reserve should always be planned.

Of course, it is also important how often you want to charge your device.

Below you will find typical scenarios and our recommended capacity for a power bank.

Intended use Recommended capacity
For the pocket Up to 5,000 mAh
For on the go 5,000-10,000mAh
For travelling 10,000-20,000 mAh

How much does a powerbank cost?

There is a wide price range between the different powerbanks. The cost varies depending on the quality and size of the powerbank. The range can go from about 8 to 50 euros.

Inexpensive powerbanks with 5000 mAh start at just 8 euros, although it should of course be noted that low capacities are cheaper than high ones. Other factors that influence the price are brand and connections.

What alternatives are there to a powerbank?

There is no real alternative to a power bank. If you don't want to risk not being able to use your electronic device on the road, you won't be able to get around a powerbank.

A power bank protects you from unexpected battery problems when you are on the road.

Decision: What types of power banks are there and which one is right for you?

If you want to get a powerbank, there are three alternatives to choose from:

  • External Power Bank
  • Outdoor Powerbanks
  • Powercase/battery case

In the following, we will show you the advantages and disadvantages of each in more detail.

What distinguishes a power bank as an external battery pack and what are its advantages and disadvantages?

The battery pack is the typical power bank. It is an extra device that you can take with you when you need it. It is usually in the form of a box or tube with USB ports.

  • Practical for on the go
  • Can be taken along when needed
  • Different versions for every situation
  • External device

What distinguishes an outdoor powerbank and what are its advantages and disadvantages?

Outdoor powerbanks are specially designed for outdoor activities. They usually also come in the form of a small box and are specially protected against dust, splash water and impacts

  • Practical for on the go
  • Specially designed for outdoor activities
  • More expensive than conventional powerbanks

What are the characteristics of a power case and what are its advantages and disadvantages?

Powercases are battery cases that, as the name suggests, act as a cover for the smartphone and have a battery built in. They are attached to the smartphone and protect it from scratches and falls. The advantage is that you always have this case with you and don't have to take a power bank with you.

  • Always on the device
  • No extra cable needed
  • Also protects against damage
  • Cannot be used as needed

Buying criteria: Use these factors to compare and evaluate power banks

To find the right power bank for you, you need to consider the following criteria:

  • The device to be landed
  • Capacity
  • Voltage
  • Current
  • Charge indicator

The following sections go into more detail about the different criteria.

The device to be charged

Decisive for the choice of your power bank is which device you want to charge with it. A laptop has a higher battery capacity than a smartphone, for example, and therefore has different requirements for your power bank. Connections can also be different, e.g. USB to USB-C. You should pay attention to this and make sure your powerbank meets your requirements.

You should also check whether there are enough connections on the powerbank, for example if you want to charge several devices at the same time.

Depending on the device you want to charge, you should choose a different power bank. (Image source: / Steve Johnson)


The capacity is probably the main criterion of a powerbank. Put simply, the capacity indicates how often a device can be charged.

Smartphone batteries usually have a capacity of around 2500 mAh.

Depending on the manufacturer, notebooks have a capacity of around 5,000-10,000 mAh.

These values are rough guidelines. Before buying, you should visit the manufacturer's website and check the capacity of the battery in the technical details.


To avoid damage, the output voltage of the power bank should not exceed the input voltage of the device to be charged. If the voltage is too low, your device may not charge. In most cases, however, this does not matter, as modern power banks have a built-in controller that automatically adjusts the voltage to the device being charged.


The amperage determines how fast your device is charged. If the amperage does not correspond to the amperage required by your device, the charging process will take longer. If the amperage is higher, you can charge another device if necessary. Powerbanks with different connections often have different amperages.

Some powerbanks have fast-charging technology. This ensures that your mobile device is charged more quickly if the device in question supports the technology.

Charge indicator

A good power bank shows you the current charge level when needed, so you always know how much capacity is left and you don't run the risk of starting the day with an empty power bank. Most power banks have several LEDs that show the current charge level by pressing a button. Modern and expensive versions also offer displays that show the battery status in percent.

Facts worth knowing about power banks

What mistakes should be avoided when using a power bank?

Extreme temperatures

High temperature fluctuations should be avoided at all costs, as they have an extreme effect on the performance of the powerbank. This applies to both cold and heat. Therefore, make sure not to use the power bank unprotected in winter and not to leave it in the sun in summer.

Locking the power bank after charging

When you have fully charged your powerbank, you should not continue to supply it with electricity in order to avoid overheating.

Do not use the power bank when it is hot

If your power bank is unusually hot, you should first let it cool down. This usually indicates an internal defect and you should send the power bank to the manufacturer.

Image source: / Zoltan Tasi