In the run-up to the test, we defined practical requirements and the following test criteria:
- Usable capacity
- Functional scope
- Size to capacity
In order to evaluate these criteria, we have defined several tests for the Powerbanks. First, the scope of delivery and the connections are checked. A measuring device is used to check the actual usable capacity of the devices.
The Powerbanks are completely discharged and the time required for charging is then measured. During discharging and charging, the temperature development is also recorded with a thermal imaging camera.
As the test progresses, the devices are intentionally short-circuited and overloaded to test how the Powerbanks react in such a case and whether they are still functional afterwards.
Finally, a drop test is performed from a height of one meter to see if the devices are still working properly. If, according to the manufacturer, the devices are protected from water and dust, this is checked in separate procedures.
In order to exclude mistakes and to ensure the load by the everyday use, each test takes place in several rounds.
The test criteria are given percentages depending on their importance. The final score is then objectively calculated from the test criteria using an algorithm.
Our product selection is based on observation of the current market. In addition to popular branded products, we also include insider tips in our selection. Criteria such as price and range of functions are an important factor to us. The test field is also determined by analysis and evaluation of customer reviews and external tests (e.g. Stiftung Warentest).
The devices are purchased anonymously or lent to us by the manufacturer. Dealers and manufacturers have no influence on the tests and our evaluation.
As soon as new relevant products come onto the market, our test field is extended by these. The new products go through the same test as the already tested devices.