How much will be charged 20000 mAh

The term power bank basically refers to an external mobile battery. It is important to find the right device for each individual requirement. Before you buy a power bank, a few questions should be answered, there are different capacities, and the charging cycles look different. A meaningful product comparison is worthwhile so that the buyer can keep track of things. It is also interesting which devices can be charged with which battery. By the way, we have put together a great infographic on our Powerbank-Test homepage.

So that the purchase decision is correct, all advantages and disadvantages should be compared. The market is full of external chargers, so good advice is needed here. First, the goal is to find out what should actually be charged with the power bank. Mostly it is about charging a smartphone, but it can also mean other devices, such as a tablet. Even GPS devices can be charged with a power bank. The same goes for cameras. This means that any device can be charged with a power bank if, for example, the input is 5 V.

The test winner among the power banks with a very good price-performance ratio is, by the way, this model from Anker!

The essentials in brief:

  • Most people think you calculate the capacity of the power bank by the capacity of the cell phone battery and get the charging frequency, for example: 20,000 mAh / 1,560 mAh = 12.8 times.
  • However, you have to note that the energy content of the power bank remains lower compared to the cell phone battery due to the lower nominal voltage. Lithium polymer batteries with a nominal voltage of 3.7 volts are mostly used in a power bank.
  • In addition, the smartphone requires a voltage of 5 volts. Theoretically, the battery voltage of the power bank has to be converted from 3.7 volts to an output voltage of 5 V at the USB port of the power bank. Energy is lost during this process - something that has to be considered.
  • With these criteria in mind, you have to work from an approx. 30% loss go out and then comes up with the above bill charge about 9 times. The values ‚Äč‚Äčalso depend on the quality of the power bank.
  • Ultimately, it is important to keep an eye on the voltage of the power bank and smartphone as well as the capacity of the smartphone and power bank battery.

Amperage and charging time

Depending on the situation, each external charger has different amperages so that the device can be charged. This must be considered. The current at the input and output has different effects. Of course, the strength of the current directly affects the time it takes for the battery to charge. The power bank can be used again quickly if the battery memory is empty. Sometimes such a product even has several USB outputs with different currents. It is possible to charge a smartphone and a tablet at the same time with a battery charger. For this, the tablet needs a connection with a higher amperage. This way the product will be charged faster.

In general, the ampere specification indicates the maximum current strength that may flow. The electrical device itself determines which amperage is required. Consumers can therefore be connected that can load the power bank with the output specification in amperes, mostly up to 2.5 A. Incidentally, according to, there will be standardized chargers from 2017, which will make it easier to charge different smartphones.

Capacities and sizes

You know the capacity of a power bank if you consider the specification in mAh. If this number is quite high, the smartphone can be charged particularly often, for example. Which capacity is suitable for the buyer is individual. There are both larger and smaller battery chargers for external use from 3000 mAh to 25,000 mAh and more. On our Powerbank main page, we have already described that at least 3000 mAh are required to fully charge a smartphone. You can also orientate yourself roughly on the capacity of the device to be charged. So it always depends on the individual needs. How often the smartphone can be charged with the external battery charger always depends on the capacity. There is even an external power bank with solar cells.

The design of the external charger

Mostly a battery charger is made of plastic, there are different designs. In many cases the surface is also made of rubber. In some cases there is a power bank made of aluminum, so everyone has to decide for themselves what they like best. There are also many accessories for a power bank. A carrier bag serves both for protection and for daily use. A standard USB cable is used for transmission, but this must be certified. The battery cells are no longer used after the complete charging process. In this respect there is no overloading. An LED display helps to see whether the external charger is fully charged.